At6702 uw

AT6702-VEHICLE MAINTENANCE
DEPARTMENT OFAUTOMOBILE ENGINEERING SEM - VII
AT702 VEHICLE MAINTENANCE
PART – A
1. What do you understand by vehicle maintenance?
Maintenance means keeping all the systems and features functioning as possible to the
manufacturers original design intent tons. Maintenance helps the vehicle to start run and stop as
the manufacturer intended, so that maximum amount of performance, reliability and service life
are achieved.
2. Explain the purpose importance of maintenance.
The purpose of vehicle maintenance can be summarized into:
(i) To keep the vehicle in good running condition
(ii) To keep the operation cost less
(iii) To provide safety on vehicle operation
(iv) To give feed back to manufactures for development and rectification
(v) To adhere to the legal requirements of vehicle operation.
After the completion of the recommended running in period for the new or reconditioned
vehicle, and during the subsequent normal working period it is necessary to give maintenance
attention to eat air specified items at regular intervals to ensure satisfactory operation and
freedom from trouble. These routine maintenance is to be done according to the manufacturers
instructions is the maintenance manual.
3. What is the mileage prescribed for first service?
With the majority of vehicles, it is used to assume that at the end of the first 500/1000 kilometers
miles if the vehicle has been driven below the stipulated maximum speed, the vehicle will have
attained it proper working condition.
4. What are the faults found in vehicle by selling agent?
The most important faults found in vehicles delivered by the manufacturers selling agents are:
(i) incorrect value stem clearances
Once there faults are rectified, the vehicle need not require much attention apart from the routine
check-up of fuel in the tank, water in the radiator, charging of battery, level of water oil etc.
5. What is the maintenance works carried out after covering first 1000km?
At the end of the first 1000 km, the engine-sump gear box, back axle casing etc: are drained and
filled up with recommended grade of lubricants. All cylinder head nuts are checked for tightness,
and the inlet and exhaust manifoldness are also checked. All working joints of the vehicle viz
carburetor dried pump clutch, brake mechanism joints are oiled well. The steering system and
spring shackles are lubricated. The cooling system is checked for leakage. Spark plugs, and
automatic ignition controls are cleaned. Fuel filters are inspected and wheel alignment and
lightness are checked.

PART – B
1. What the types of maintenance and shortly brief/them.
Types of Maintenance
maintenance or unscheduled maintenance
Preventive Maintenance
failure. Primary goal is to prevent the failure of equipment before it actually occurs. Preserve and
enhance the equipment or vehicle reliability by replacing worn components before they actually
fail.
Preparation of checkup
Identifying the parts and
done
Maintenance Records or log
includes a date, mileage as of that day, details of about the type of work done, and who
performed the service.
replacements etc are done hence monitoring activity an be done early.
Determining preventive Replacement Time
Figure: Optimum Age Replacement Model
It can be seen that the corrective replacement cost increases as the replacement interval
Increases. And the preventive maintenance cost decreases. On combining both cost we can get an
optimum point that minimizes the cost.
Checklist
A check is a simple, usually usual, confirmation that the equipment or vehicle is ready for further
use. A checklist gives us. The list of components that as to be checked at regular interval time
may be

2. Briefly explain the points to be taken care in establishing an automobile.
Service station/workshop
1. Service enhance: The approach to the service reception should be smooth.
2. Reception/Diagnosis (Service adviser)
(i) Warm and friendly Reception
(ii) Careful listening to customer’s Requests correct diagnosis.
3. Filling Repair order and Estimates (Service adviser)
(i) Accurate preparation of Repair orders
(ii) Clear Explanation of work and cost estimate agreement obtained.
– distance traveled, Fuel filling details
customer.
agreements. (gets signature from customer).
4. Work allocation/Instructions (Fore man / Technician)
(i) Work allocated for efficiency (considering technician skill level completion time-outside
work required etc).
(ii) Accurate work instructions (eg. Nature of problem). Repair procedure proper steps
completion time etc).
Upholstery seat cover works
Body Trim Bonnet (Engine Compartment cover)
Fender (Wing) The panel above the wheel and side of the vehicle
5. Repairs (Technicians)
(i) Reliable work, quickly accomplished
(ii) Work performed neatly, observing proper safety rules.
6. Final Inspection[Foreman / Chief Technician]
(i) Quality of work checked (correct items Repaired)
7. Delivery preparation (Service Advisor)
(i) Check on what work was done
(ii) Clean inside and outside of vehicle
(iii) Prepare Documentation
8. Delivery(Service adviser)
(i) Explain Details (work done, charges, spare parts)
(ii) Receive payments
9. Post service follow-up (service Adviser)
(i) Check with customer Regarding work quality
(ii) Enquire About customers satisfaction.
3. What are basic instruments needed for turning of petrol engine?
1. Compression Gauge
To measure compression pressure
Busing identified
Borden tube pressure Gauge is used.
2. Vacuum GaugeSimilar to compression Gauge.
Contraction Takes place and goal is marked reverse. 0 – 10 .

If comp pr. reduced. or low Gaskets, valve leak valve timing. Change of comp & comp Ring
crack in the cylinder head warpage due to insufficient tightening of the head
Bead is ground to avoid warpage.
Tachometer, - Engine rpm.
Speedometer - Instruments linear velocity of vehicle
Odometer - Distance trowel of vehicle
Tripmeter - Reset (distance travel of vehicle) used in autos & Taxis.
4. What is the sequential procedure for tuning a petrol engine?
 Loose spark plugs start Engine to Blow out carbon and dust, start-off Engine and Remove
plugs.
 Test Engine compression:-
 If the comp. pr is less, perform Engine service that will Eliminate the trouble of the
compression is alright Re-Install the spark plug.
 Remove distributors cap clean it. Visually check for carbon tracks and carroded terminals
chips etc. Replace it if hot in good condition.
 Spark due to current flow through ionized Gases (400v),
 Lower part is aluminium alloy (10w tension).
 Arc due to flow of current flow and material transfer and carry electrons with it.
 The upper part(cap) is Backlight (high tension).
 Due to carbon deposit – short circuit and spark Jumping
 Any crack in the cap – makes short circuit cap can’t be Recondition – it should be
Replaced.
 clean and inspect distributor Rotor, if it is not in Good condition,
o Colour of surface indicate the status of cylinder.
 11. Check Battery state of charge, water level and hold down clamps. 12. Check battery
cables for damage corrosion and loose connections. 13. it the battery is overcharged or
undercharged check the dynamo (Alternator) and
 regulator 14. check drive belt and Tighten or replace them as require
 -fn of generator or alternator

 15. Check the intake manifold bolts for tightness to proper specifications. Even a slight
 leak will reduce engine performance 16. Check fuel lines for tight connections.
 nto the fuel line when pump is
 17. Check the cooling system for water leaks collapsed hoses, correct, coolant level. 18.
Check and adjust accelerator linkage.


 Can be adjusted
 In linkage 19. Check crankcase ventilation system.






 20. Remove carbureter air cleaner and check choke value clean or replace air filter
 element if necessary.
 lter



 21. Check and adjust contact point dwell and ignition homing.
 22. Adjust idle speed and mixture.
 23. Check the lube-oil dipstick level.

 changed or not
 24. Check the working of lights and horn. Adjust the head lamp for proper focusing.
 25. Check steering system for easiness.
5. Write down the steps involved in servicing the ignition system with contact breaker
points.
1. Clean, recap or Replace spark plugs.
- clean with wire brush
- check for cruel in insulation.
2. Clean and inspect the ignition coil.
If the tower (Top) is cracked replace the coil.
3. Replace the primary wire (coil) to distributor and coil to switch it is broken make sure that
the connections are clean and Tight. 4. Clean and inspect the distributor cap. 5. Examine the
Rotor. 6. Twist the distributor shaft in the direction of rotations and release. It should snap back
it if
Does not the distribute advance mechanism must be repaired.
7. Inspect the contact points replace them it necessary check and set the gap.
- 0.4 to 0.5 gap is maintained in the contact points.
8. put a small amount of cam lubricant (white silver lube) on the distributor com. 9. check and
set the Dwell using a Dwell meter 10. Adjust the timing using a Timing light and Techometer 11.
check whether the advance mechanism works using the timing light.
6. Briefly explain the procedure for servicing the spark plugs.
Servicing of spark plug:-
1. Remove H.T wire from Spar plug to do this slightly twist the rubber protector boot which
partially covers the fluid, to break the seal, grasp the boot and pull it away from the plug
with a steady even pressure. 2. Mark each wire with the cylinder no.(user paper Tape). 3.
Remove any foreign material from around the plug hole by wiping with a rag (or) Blowing
air waste cloth. 4. Remove the spark plug and Gaskets and heap them in the order by the which
they are
Removed. An isolated plug showing an abnormal condition indicate that the problem is
with that cylinder. 5. Wipe if the exterior of the plug and inspect for proper sealing. 6. Check for
burned electrodes and dirty, foul (or) cracked insulators what does the sp face
reveal?

Fouled Condition Indication
By soot Dull black, velvety
carbon deposits
Fouled by oil Shining black wet carbon
deposit
-out value guides.
-out cyl/pistion rings
Over heated Insulator burnt whit with
pearly deposited of
metabolic parts eroded
electrodes.
(M14-spark plug
thread M10 most used one, M18 For heavy engine. 8. Adjust the Gap it necessary by bending the
ground electrode (using a spark plug gauge). 9. To clean the plug wash it with a petroleum
solvent to Remove oil film. 10. Dry the plug use an Abrasive type cleaner for the best cleaning
job. 11. clean the threads with & wire brush 12. Blow out all abrasive particles with compressed
air. 13. Use a thin stiff Blade to clean the space between the plug shell and insulator. 14. scrape
out all carbon particles turn the plug and dissolve the deposit out. Repeat until the
plug is thoroughly clean. 15. Blow out the remaining dirt with compressed air. 16. Widen the
plug Gap by bending the Ground (side) electrode so that an ignition point file
may be inserted between the electrodes.
Figure:
17. fill the electrodes until all the carbon is removed and the tip of the central electrode is flat
across the top. 18. Adjust the Gap to correct specification. 19. Ensure that the plug seating
surface in the head is clean. 20. Install the plug. 21. Tighten the plugs using a Torque wrench to
correct specification. (most) 4mm plugs are
Tightened to approximately four Kg N. 22. It torque wrench not available, Tighten the plug
finger tight. Then using a socket wrench
Tighten it approximately halt a turn. 23. Inspect the plug wires. It insulation is brittle. Replace
the wire. 24. Clean the distributor cap. 25. Re install the plug wires to the same cylinder from
which they were removed.
7. Write down the daily and weekly maintenance schedule o an automobile.

Daily Maintenance
1. Clean vehicle 2. Check engine oil level and top up if necessary 3. Check radiator water level
and top up 4. Inspect tyre for normal pressure and ensure that no tyre is fist 5. Check for fuel in
tank 6. Check up whether light and electrical accessories are functioning well 7. Check up brake
for normal functioning 8. Start engine and check up performance
Weekly Maintenance
1. Check electrolyte level in battery and add distilled water if necessary 2. Clean battery
terminals and apply vasoline to prevent corrosion 3. Check tyre pressure and inflate if necessary
to correct pressure
chamber etc. 6. Wash vehicle with water mixed with detergent or with soap water. 7. Check oil
leak if any from engine, transmission and differential and arrange to rectify. 8. Clean plays and
refit if the vehicle is petrol driven 9. Tighten joint belts and axle bolts. 10. Tighten spring and
shackle bolts and nuts if necessary 11. Adjust fan belt play if necessary. 12. Check up water
pump grease cup and repack, if necessary 13. Check whether Dynamo is functioning well.
Adjust regulator if necessary. 14. Check oil in steering box gear box and differential and top up
if necessary.
8. Write dour the monthly, quarterly and half yearly maintenance schedule an automobile.
Monthly Maintenance
1. Service vehicle at appropriate data 2. Check up and adjust free ply of brake 3. Check up and
adjust free ply of clutch 4. Soap wash vehicle, polish if the vehicle is station wagon. 5. Change
engine oil at appropriate mileage. 6. Check up and tune up vehicle (minor) petrol driven 7.
Tighten engine gear box and body mounting bolt. 8. Remove all the wheels, check brake drums,
brake linings, change brake linings and turns
up brake drums if necessary. 9. Examine all wheel bearings for what before refitment. 10.
Remove old grease and repack with fresh grease.
Quarterly Maintenance
1. Tighten body bolts and change packing if necessary 2. Blow and adjust brakes 3. Carry out
engine tune up if petrol driven vehicle 4. Check up pedals side play and rectify 5. Check up and
renew engine counting beds 6. During service, remove and clean shackle pin if necessary. 7.
Check up steering linkages and play and adjust if necessary 8. In case of diesel engines overhaul
injectors, besides the above items of wash, all the items
mentioned in the monthly maintenance schedule should be carried out during quarterly
maintenance also.

Half yearly maintenance or fitness certificate work
1. Remove gear box 2. Check differential
3. Overhaul all four wheel brakes and the Universal joints
4. Top over haul engine end decarbonizes
5. Over haul carbonator
6. In diesel overhaul injectors and pumps and recalibrate (This should be done by the
authorized agencies and preferably in air conditioned rooms).
7. Overhaul water pump
8. Overhaul dynamo and self starter
9. Overhaul exhauster or air compressor
10. Check all wirings and switches
11. Carryout body repairs, including linear work
12. Repaint vehicles, if lorry or van.
9. Explain the various types of records books and form that are being used in automobile
service station of cards.
Dealer: Place: Data of Sale: SERVICE TYPE
Ro No:
Mileage:
Kms:
Ro Date:
Engine No:
Frame No:
Mileage (Kms) 10000 30000 50000 70000 90000 110000 130000 150000 Service type
Mileage(Kms) 170000 190000 210000 230000 250000 270000 290000 310000 Service type
Mileage(Kms) 330000 350000 370000 390000 410000 430000 450000 470000 Service type
Mileage (Kms) 490000 510000 530000 550000 570000 590000 610000 630000 Service type
S.No. CHECK ITEM CHECK STATUS REMARKS 1 Basic engine components
Engine oil
Engine oil filter
R
R
2 IGNITION SYSTEM
Battery
T
3 FUEL AND EMISSION CONTROL
Pre-filter
Water sediment filter
Air cleaner filter
R
CA
C
4 CHASSIS AND BODY
Brake pedal, Parking brake
Brake pads and discs
Brake lining and Brake drums
CA

CA
CA
Brake line pipes and hoses
Brake fluid
Clutch
Power steering fluid
Ball Joints and dust covers
Tyres and inflation pressures
Lights, horns, wipers
Steering wheel linkage and gear box oil
Front and rear suspension
Tightening of bolts and nuts
R
CA
CR
CR
CA
CA
CA
CA
T
5 AC/Cooler Refrigerant NA C Clean; R Replace; CA Check & Adjust; CR Check & Replace; T
Tighten ADDITIONAL JOB: MILEAGE 1,50,000 4,50,000 TIMING BELT Replace Replace
Name of the Inspector
Signature
The status and remarks for all the items mentioned above are indicated on the check sheet
during the maintenance operation.
Vehicle Regn No: Job No:
Chassis No: Date:
Table: Road Test Report
S. No. Parameter to check Before work After work 1 Front side abnormal noise 2 Rear side
abnormal noise 3 Front/rear suspension noise 4 Steering noise 5 Brake caliper noise
body operation 10 Overheating of engine AC and Non AC
operation 11 Brakes poor / Weak line effective / noisy 12 Wheel bearings noisy
13 Drive shaft noise / vibration
14 Vehicle pulling to one side
15 Poor pick up of vehicle (with AAAC and
without AC)
TABLE: TRIP SHEET
Name and Address of the Agency REPORT TO
Mr. / Mr.-------------------------------------
--------------------------------------------------
---------------------------------------------------

Engaged by Arranged by----------------- No.------------------- Date:------------------- Vehicle
Number-----------------------------
Drive Name -----------------------------------------------
Closing Time ------------ Starting Time------------ TOTAL Time------------
Signature of the Customer
Hire Charges
Charge Per km
Driver Batta
Excess Hours
Excess Kms
Service Tax
Permit Charges
Rupees Paise
Advance Rs.-------------- TOTAL
Driver’s Signature For Agency
Road Test Report:
1. The road test inspector or the machine makes the road test report after the
completion of the maintenance operation.
2. This report contains the vehicle registration number, chassis number; job no, data of
test etc.
3. The parameters to be checked included the following:
cle.
The road test report gives a fare idea of the condition of the vehicle before and after the
maintenance operation.
Trip sheet
The trip sheet gives the entire details of the vehicle before and after a trip. The starting km and
ending km, time of start and closing of the journey time and the charges per km and also the
overall cost of trip is described in the trip sheet.
Logbook
The logbook of a vehicle gives the details of the vehicle, which will be useful not only for the
owner of the vehicle but also to the mechanic who might take the job of vehicle maintenance
latter.
The logbook contains the following details:

Conclusion:
The different statement and records required for the repair and maintenance works were prepared
and the uses of records were studied.
Vehicle Monthly Maintenance Form (T1)
Cooling system
Part Condition Comments
Radiator
Coolant
Hoses
Water Pump
Fan
Dashboard warning light
Brakes Front Brakes
Master Cylinder Brake Fluid Hoses and brake pipes Brake pedal (any play?) Disks Pads Rear
Brakes
Hand brake Hoses and pipes Shoes
Front Lights
Side light-left Side light-Right Headlight-Left Headlight – Right Full beam – Left Full beam –
Right Indicator – Left Indicator – Right
Rear Lights
Tail light – left Tail light – Right Brake light – Left Brake light – Right Indicator – Left Indicator
– Right
Charging System
Battery Fluid level Battery Terminals Alternator Fan belt Dashboard warning
Ignition System
HT leads
Distributor Cap
Rotor Arm
Coil
Spark Plugs
Tires and Wheels
Front Right
Front Left
Back Right
Back Left
Spare Wheel
Jack and Lu tool Steering

Steering fluid Steering wheel play Track rod ends Upper ball joints Lower ball joints Wheel
bearings CV Joints
Gear Box
Gearbox unit Transmission fluid – auto Gear Box oil – manual

ENGINE AND ENGINE SUBSYSTEM MAINTENENCE
1. What do you mean by engine overhauling and explain its necessity?
Overhauling a machine, strictly speaking, means going over it. When a vehicle engine is being
overhauled, it is completely taken apart, every piece is inspected and what ever piece shows
appreciable wear is reconditioned to its original shape and dimensions or replaced by a new one.
After this the engine is reassembled, put on a test stand, started, tuned up, and carefully tested.

Since it is difficult to keep and accurate maintenance log for a vehicle away from the garage
sometimes for days or week and since the operators of these vehicles need not be first class
mechanics, and because nobody is concerned how efficiently an engine works as long as it runs
and pulls the lead, a general overhauling of the engine is done at regular intervals, every 12 or 18
months as the case may be.
In general, the methods of overhaul do not differ from maintenance procedure, except that in
overhauling a more strict examination is in order as the intervals are considerably greater than in
maintenance work, a part even slightly worn, if it is not subject to maintenance inspection
periodically, should therefore be either reconditioned or replaced.
2. What is the precaution to be taken before dismantling engine.
Dismantling:
One of the important rule to be adhered in dismantling an engine is to mark all parts and identify
them as the engine is dismantled. It is particularly important to mark camshaft gears and valves if
manufacturer’s marks cannot be found. Centre and punch markings will serve the purpose.
Changing the tyres around: In order to obtain the greatest mileage from a set of new tyres
(including the spare one too) it is necessary to change then round at intervals of about 3000 miles
for rear drive vehicles and 2000 miles for front drive vehicles during this useful life.
Cuts in tyre treads: Since water and grit penetrate and destroy the cords, small cuts in tyre has
to be plugged with readily available “plastic tyre stopping large cuts should be vulcanized at tree.
Punctures: When a puncture occurs, on the road, the vehicle should be stopped and the when
changed Tube less tyres can be driven to a safe distance even though they puncture, because,
they lose their air more slowly. Small punctures can be repaired with rubber patches and rubber
solution. Minimum amount of solution is to be applied and it is allowed to dry for 5 to 10
minutes before placing the prepared patch: After this some talc is sprinkled over the patch to
prevent sticking to the outer cover major repairs of the tubes are to be done with a professional
vulcanizer.
When the vehicle is stored for a long period all the tyres are to be removed and stored an cool
dry place, or the vehicle can be jacked off the ground and the tyres can be rubbed with French
chalk.
3. Write down the stepby step procedure for engine removing and dismantling?
Removal of Engine from the vehicle
A general procedure for removing the engine from the vehicle can be summed up as follows:
(i) Drain oil from the sump (ii) Drain water from radiator and jackets, opening all taps in the
cooling system. (iii) Remove engine bonnet and where filled vertical side members. (iv) Remove
radiator (v) Disconnect cable from battery (vi) Disconnect fuel fed supply line (vii) Remove L.T.
cables from ignition system and disconnect wiring to horn. (viii) Disconnect radiator hose from
the engine side (ix) Disconnect oil pipe to instrument pressure gage and thermometer pipe (x)
Remove electric horn if liable to obstruct engine removal (xi) Take off cable connections to
dynamo and starting meter (It is better to remove both
starting motor (It is better to remove both starting motor and dynamic if readily accessible,
as this allows better access to engine mounting nuts) (xii) Remove exhaust pipe flange nuts (xiii)
Take off accelerator and air choke controls (xiv) Take out all foot boards as far back as rear of
gear box (xv) Disconnect clutch pedal operating rod and pull of spring. (xvi) Disconnect foot
brake pedal and hand brake, if anchored to engine unit (xvii) As the engine, clutch, and gear box
are built as integral unit an most medium vehicles, it is
more convenient to remove the complete unit than gear box; these operations can be

performed better on the bench than on the chassis and much time save thereby
METHOD OF REMOVING ENGINE FROM VEHICLE

At this stage it is advisable to stop and look around the engine unit to make sure that all
connections with the chassis frame, dash board, and body work have been released. The final
operation will then connecting the front universal joint (just behind the gear box) and the
earthing cable or strip between the engine unit and chassis frame, finally removing the nuts of

the holding- down studs or bolts of the engine unit mounting. Usually there are two rubber
mountings at the front end of the engine and a single large rear mounting on the gear box.
Once the engine is freed from the chassis a single or double rope or chain sting should be
adjusted carefully round it making sure that the sling comes under the strongest part of the unit
and does not foul any of the more vulnerable components like, the ignition unit, oil filter or
carburettor. Now locate the chain on the lifting hook of the crane, so that when the engine is
raised the front will be on a slightly higher level than the rear. Finally, lift the engine slowly and
at the same time push the chassis rearwards so that the clutch housing will clear the cab opening.
It is convenient to mount the engine an a suitable engine stand, which will have the following
features.
(i) It should take a range of engine sizes (ii) Convenient means for securing the engine
CYLINDER HEAD BOLT WRENCH

CAMSHAFT BEARING TOOL
VALVE SPRING COMPRESSOR
PISTON RING TOOL OIL SLIMP SCREW DRIVER
3. Explain the Procedure for Decarbonizing the Engine
The intervals at which decarbonizing of the engine becomes necessary, depend upon a number
of circumstance being governed by the performance and tendency of the engine to knock under
acceleration or hill climbing . It is unwise to post pone decarbonising, since increase engine wear
will result and the performance will also continue to fall off.
The hard carbon deposit found on motor vehicle engine consists partly of carbon from
lubricating oil and fuel and partly of hard abrasive siliceous matter carried as fine dust particles
by the air of the fuel mixture.
The procedure of decarbonising an engine is as follows:
(1) Remove the cylinder head and clean with paraffin (2) Remove the gasket and check for
scratches, indentation and other defects. (if necessary use
a spare gasket) (3) Clean the cylinder block machined faces with paraffin and dry it so as to
prevent adherence
of carbon dust. (4) Plug the water circulation orifice in the cylinder block with cotton waste so as
to prevent
dust entering.

carbon deposits from their crown with a flat scrapper, leaving a ring of carbon about 1/8”
wide around the outer periphery of the crown.
The reason for this is that this carbon which slightly overlaps the edge tends to prevent oil from
parsing upwards, tests have shown that the oil consumption in slightly reduced when this carbon
ring is left.
LEVER TYPE VALUE SPRING COMPRESSOR

TOOLS FOR COMPRESSIG OVERHEAD VALVE SPRINGS

BOLT, NUT AND WASHER- PLATE FOR REMOVING VALVE GUIDES (6)Having
remove the carbon from the two pistons, right the crank shaft until the next pair of pistons come
to top. (7) Wipe the cylinder barrels of the first pair and stuff clean rags or waste in to the top
opening, to keep out carbon scrapped from the second pair of piston. (8) Remove the carbon
from the second pair as before (9) Continue the above proceeding until all the piston are over
(10) Clean the valves and metal around them (11) Scrap the cylinder head off carbon with special
scrapper

or scriber. (14) Remove all plugs (with cotton waste) and give the parts a final cleaning with a
suitable cloth. (15) Smear each barrel with engine oil and rotate the crankshaft a few times so as
to distribute the
oil evenly over the surfaces. (16) Replace the gasket, (use a new one if necessary and cylinder
head and tighter the holding
down nuts on finger tight. (17) Tighten the cylinder head nut in the order prescribed by the
manufacturer, using the
appropriate torque by a torque wrench. (18) Replace the cylinder head fittings.
The above procedure is for, when the engine requires only decarbonising. When a complete
over haul is done, decarbonising also takes part as a routine over haul procedure.
4. Explain the procedure for Dismantling an engine?
(i) Remove cylinder head (ii) Take off all external accessories, like motor , dynamo ignition unit
or injection pump. (iii) Remove engine sump (iv) Rake off timing gear cover, after removing
pulleys, etc (v) Remove clutch unit (vi) Take out all valves with their tappets, rocker arms, push
rods, etc (vii) Remove connecting rod caps, pistons and connecting rods (viii) Take off timing
chain and remove sprockets (ix) Remove crank shaft with flywheel by taking off main bearing
caps. (x) Remove camshaft (xi) If necessary, drive out valve guides (xii) Disconnect oil pump
drive and remove oil pump at the most convenient stage in the
proceeding operations. The oil filter and cleaner are removed early on, also the disstick or oil
level gauge.
As the components are removed they should be grouped conveniently on a bench or table,
prior to cleaning. Before taking of any component, make sure that it is marked identically with
mating part.
5. Briefly mention the methods used for Cleaning the Engine components?
If relatively few engines are to be reconditioned at appreciable intervals, the paraffin bath
method of cleaning is the most economical. The group of components are immersed in a bath or
deep tray containing paraffin and scrubbed with a wire or bristle brush to remove all dirt.
INSERTING LINERS: SCREW AND NUT METHOD

‘BUMA’ TOOL FOR REMOVING CYLINDER LINERS
After cleaning the parts are placed in a metal plate or slab to dry in a warm place.
The motor garages uses a high pressure spray directly by a nozzle on a flexible hose to the parts
which are placed on perforated draining tray; small parts dealt with collectively by placing in a
special container. The dirt and grease are quickly dislodged and the paraffin is thoroughly
filtered through the detachable filter box before it drains into the reservoir at the bottom, thus
there is no need to clean any sludge from the tray or reservoir.

Caustic soda made into a solution with hot water, hot saturated, sodium carbonate solutin and
trichloro ethelen are other cleansing agents used.
6. Explain the stepby step the examination and checking of Components?
Often a careful scribing of the various engine parts will reveal indications of damage excessive
wear, surface cracks, and other defects without the need for more elaborate inspection. The
simple parts such as studs, bolts and nuts should be examined for signs of damage or stripping.
The nuts can be run down the threads as a check. Bolts, nuts and washer faces must be free from
edge burrs. The valves, springs , collar’s and retainers, are their examined for wear and shape.
The piston should be carefully inspected for surface damage and for wear effects in the ring
grooves, on the skirt portion etc. Blackened areas on the land or skirt denotes areas of gas blow-
by , and these are noted. The piston crown should be examined for cracks or distortion and the
gudgeon pin holes for signs of hammering effect.

The big end bearings of the connecting rod and the journals of the crank shaft are inspected for
signs of cracking, scoring or other surface defects. The can shaft bearings and journals are also
checked.
The timing gear teeth will indicate by visual and meshing tests, whether any undue damage or
wear has occurred. Similarly the condition of the timing chains rocket teeth are also checked.
When spares are available , they can be employed for comparison purpose with the those under
inspection.
Now the cylinder blocks and head are inspected for the following defects.
1. Cracks in the water jacket walls
2. Damaged machined faces
3. Fractured Flanges
4. Cracked Valve seatings or loose seating inserts
5. Scored cylinder barrels or ridging near the top
6. Loose or damaged cylinder head studs.
After the visual inspection the cylinder measurements one taken accurately to find out the wear.
The cylinder, piston, piston rings, crankshaft journals, connecting rod bearings, camshaft
,connecting rods, crank shaft, timing gears, chain wheels and chain are all measured for weak.
The valve stem, its seating, guide bushes etc: are also to be checked for wear.
Worn cylinders can be reconditioned by the following methods.
(1) Machining in the lathe
(2) Regrinding in the lathe or with special machines designed specifically for this purpose.
(3) Boring with cutters, using a portable machine that can be clamped to the cylinder block.
(4) Horning either by portable or fixed machine
(5) Reaming with portable or fixed machines
When cylinder liners are used, it is easy to remove the work cylinder lines and insert a new one,
and the cylinder reboring can be dispensed with. (i) Cracks in the piston crown (ii) Burning of
crown. (iii) Scored lands and skirt (iv) Blackened areas on land and skirt which are sign of gas
leakage from combustion chamber.

The other engine components that are to be examined are the various bearings viz, the crank
shaft bearings, the camshaft bearings, the connecting rod big end and small end bearings, the
crankpin, the connecting rods, the valves, their seatings, guide bushes, the rocker arm, push rods,
cam profile, timing gear, chains of chain drive where used, the ignition system of the S.I.
engines, the fuel pump and nozzles of C.I. engines etc.
After all the engine components are inspected and tested for their measurements, shapes and
performance the reassembling of the engine begins.

METHOD OF ADJUSTING VALVE STEM CLEARNACE OF OHV ENGINES
A USEFUL VALVE FACING TOOL
7. What are the special tools and basic instruments required for maintenance?
Basic Instruments Needed
For Engine:
1. Compression Gauge 2. Vacuum Gauge 3. Tachometer
For Ignition System
1. Power Timing Light 2. Dwell meter 3. Voltmeter 4. Ohm meter
For Electric System
1. Voltmeter 2. Ammeter (0-30 Amps) 3. Tachometer 4. Hydrometer 5. Batter Load Tester
For Fuel System
1. Fuel pump Pressure Gauge

For Emission Checking
Exhaust Gas Analyzer
For Cooling System
Coolant Thermometer
8. What are the common troubles / Faults that normally occur in an automobile?
Cooling System Problems and Causes:
Engine Overheating 1. Loss of coolant 2. Defective Thermostat 3. Defective water pump 4.
Collapsed Radiator Hose 5. Excessive Rust & Scales 6. Obstructed air passage through Radiator
7. late Ignition timing 8. Combustion leak into cooling system 9. Improper coolant mix 10.
Defective Temperature Gauge
Engine Runs Too Cool
1. Defective Thermostat 2. Defective Gauge
Fuel System Problems and Causes
Carburetor flooding
1. Worn needle and sear 2. Leaky float 3. Excessive fuel pump pressure 4. Improper float
adjustment
Rough Idle:
1. Improper idle Mixture 2. Poor Compression 3. Intake manifold leak 4. Defective spark plug
wires 5. Cracked distributor cap 6. Stuck PCV valve
Stumbling During Acceleration
1. Defective accelerator pump 2. Improper adjustment of Acc. Pump 3. Ignition Misfire
Sluggish Performance
1. Late Ignition Timing 2. Too rich or too lean mixture 3. Defective advance mechanism
Ignition system Troubles & causes
Engine Misfires at All Speeds
1. Defective plug wires 2. Cracked distributor cap 3. Fouled spark plug 4. Burned values
Engine Misfires During Acceleration
1. Defective plug wires 2. Fouled or worn plugs 3. Burned contact points 4. partially shorted
ignition coil 5. Open capacitor 6. Poor primary circuit 7. Carburetor Problems
Engine Misfires at high speeds
1. Insufficient Dwell angle 2. Carburetor Problems
Hard Starting
1. Burned contact point 2. Improper ignition timing 3. Low Battery 4. Low Battery 5. Open
Capacitor 6. Ignition Timing too much advanced
Starting System Problems & Causes
Battery Not holding charge
1. Internal defect of battery 2. Dirt on Terminals / Loose Terminals 3. Electrical leakage/ shorts
4. Excessive Electrical usage with car stopped / idling 5. Battery not used for long periods.
Battery Always undercharged
1. Defective alternator / Generator 2. Low voltage regulator setting 3. Infrequent or slow driving
with heavy electrical loads 4. Excessive charging circuit resistance 5. Sulphated Battery 6. Too
Many Electrical Accessories
Battery Uses Excessive Water
1. High voltage regulator setting 2. Sulphated Battery 3. High temperature
Slow Cranking Speed

1. Excessive starter circuit resistance 2. Dragging starter armature 3. Shorted armature or field 4.
Excessive engine friction 5. Worn starter Bushes
Starter Spins without Engaging
1. Defective Bendix drive 2. Dirt or Burr on starter shaft
Starter Clicks without Cranking
1. Defective solenoid switch 2. Open starter cable 3. Defective starter
Starter Switch or Solenoid Chatter
1. Poor battery connection 2. Defective solenoid 3. Excessive starter circuit resistance No
Cranking, No Solenoid Click
1. Defective starter or ignition switch 2. Broken wire, solenoid or switch 3. Defective solenoid or
switch
Charging System Problems & Causes No Charge Rate:
1. Defective alternator /Generator 2. Defective voltage regulator 3. Open or grounded field wire
4. Open circuit 5. Worn or stuck brushes
Low Charge Rate
1. Regulator out of adjustment 2. Defective regulator 3. Excessive field circuit resistance 4.
Defective alternator/ Regulator 5. Worn Brushes 6. Sulfated Battery
High Charge Rate
1. Regulator out of adjustment 2. Defective regulator 3. Defective Battery 4. High battery
temperature 5. An accessory drawing excessive current even when the engine is not running.
Problem:
Due to open primary circuit:
1. Burned or oxidized ignition points 2. Ballast Resistor burned or open 3. Ignition points not
closing 4. Breaker arm binding on pivot post, preventing closing of points 5. Breaker arm spring
weak or broken 6. breaker arm distorted or bent 7. Dirty ignition points 8. Primary lead
connection loose 9. Primary winding open 10. Open ignition switch circuit
Due to short circuited Primary Circuit
Grounded primary coil winding, grounded ignition switch or a lead will cuase excessive current
flow and will usually cause wires to burn. Possible causes for Grounded primary circuit:
1. Ignition points not opening or closing due to improper adjustment. 2. Ignition points not
opening due to worn rubbing, block on Breaker A.R.M 3. Faulty insulating bushing on breaker
ARM 4. Cracked or faulty insulator at Distributor, Primary Terminal 5. Grounded condenser. 6.
Distributor-To-Coil lead grounded 7. Primary coil winding grounded
Due to Faulty secondary ignition circuit
1. Corroded spark plug cable terminal 2. Cracked insulation on cables (H.T) 3. Ignition so weak
or ineffective 4. Moisture on ignition coil , terminals, distributor , 5. Improper type of spark
plugs 6. Cracked distributor cap or burned carbon brush in the CAP. 7. Improper connection to
spark plugs (not correct as per firing order) 8. Spark plugs damaged, Dirty or wet porcelain
cracked or gaps improperly adjusted. 9. Rotor contact spring Bent or Broken 10. Distributor rotor
grounded 11. Distributor cap centre terminal broken or missing
Due to Battery
1. Battery run down 2. Terminal loose or badly corroded 3. Improper ground 4. Battery cable
undersize.
Due to Excessive fuel supply (flooding)
Accumulation of liquid fuel in the intake manifold as well as cylinder. The engine won’t
start until, the rich mixture formed by flooding .

Reason
1. Choke not operating properly 2. Automatic choke not properly set 3. Float level set too high 4.
Dirty worn or faulty needle valve seat 5. Float sticking or rubbing against side of fuel bowl. 6.
Leak in float allowing fuel inside 7. Fuel pump pressure too high Due to insufficient fuel
supply
1. Carburetor inlet needle stuck in its seat due to gum in fuel 2. Float level too low 3. Clogged
inlet filter at carburetor 4. Faulty or insufficient capacity fuel pump 5. fuel pump strainer clogged
6. Faulty fuel pump Bowl Gasket 7. Fuel line from tank clogged or restricted
When Engine is Hot
Hard starting of engine under hot conduction is mainly due to over supply of fuel (flooding) in
rare cases an ignition coil may loose its efficiency when it is hot and cause ignition failure.
When Engine is cold
Apart from the conditions listed under engine won’t start the following conditions are also to be
checked. 1. Choke setting too lean 2. Fuel may have kerosene, water or ice 3. Ice in fuel lines 4.
Engine is cranked too slowly or won’t turn because:
a) Engine oil too thick in sub-zero weather
b) Battery too weak due to very low temp 5. Another possibility even though remote is that the
water pump is jammed with ice, which
will interfere with cranking engine if fan belt is tight.
Due to vapour lock
Flow of fuel to the mixing chamber is stopped (locked) By the formation of vapourrized fuel
pockets or bubbles caused by overheating the fuel by hot fuel pump, hot fuel lines or hot
carburetor.
High ambient temperature, hard driving defective engine cooling and high altitudes are
contributing to vapour lock.
After long period of non usage of vehicle
1. More volatile components in the fuel, have evaporated and the remaining ones are not
sufficiently volatile to form a combustible mixture. 2. Low or run down battery 3. Corrosion of
engine moving parts These troubles are more humidity climate and near salt water.
Reasons for the stalling of engine
1. Engine idle speed set too low. 2. Large air leakage in take manifold 3. ignition points need
attention 4. Vapour lock 5. Over supply of fuel (flooding) 6. Valves set too tight 7. Needle/ seat
of carburetor inoperative 8. Contaminated fuel 9. Choke sticking or improperly adjusted 10.
Faulty ignition system 11. Spark plugs damp/Dirty or incorrect gap 12. In operative distributor
advance 13. Restricted exhaust system 14. Burned, warped or sticking valves 15. Low
compression 16. Engine over heating 17. Loose or corroded wire connections 18. Incorrect idle
mixture adjustment 19. Incorrect carburetor float setting 20. Leaking EGR valve
UNIT – III
PART – A
1. Draw the carious clutch pedal positions and explain?

2. Draw the clutch release bearing and finger arrangements and explains?

PART – B
1. What is clutch slipping Explain?
Maintenance and Servicing of Clutch:
When a vehicle enters the shop for clutch troubles, one should test – drive the vehicle. While the
vehicle is being test – driven, one should check the action of the clutch pedal, listen for unusual
noises, and feel for clutch pedal vibrations.
There are five types of clutch problems – slipping, grabbing, dragging, abnormal noises, and
vibration. It is important to known the symptoms produced by these problems and the parts and
the parts that might be the cases.
Slipping:
Slipping occurs when the driven disc fails to rotate at the same speed as the driving members
when the clutch is fully engaged. This condition results whenever the clutch pressure plate fails
to hold the disc tight against the face of the flywheel. If clutch slippage is severe, the engine
speed will rise rapidly on acceleration, while the vehicle gradually increases in speed. Slight but
continuous slippage may go unnoticed until the clutch facings are ruined by excessive
temperature caused by friction.
Normal wear of the clutch lining causes the free travel of the clutch linkage to decrease, creating
the need for adjustment. Improper clutch adjustment can cause slippage by keeping the release
bearing in contact with the pressure plate in the released position. Even with your foot off the
pedal, the release mechanism will act on the clutch fork and release bearing.
Some clutch linkage are designed to allow only enough adjustment to compensate for the lining
to wear close to the rivet heads. This prevents damage to the flywheel and pressure plate by the
rivets wearing grooves in their smooth surfaces.
Other linkages will allow for adjustment after the disc is worn out. when in doubt whether the
disc is worn excessively, remove the inspection cover on the clutch housing and visually inspect
the disc.
Binding linkage prevents the pressure plate from exerting its full pressure against the disc,
allowing it to slip. Inspect the release mechanism for rusted, bent, misaligned, sticking, or

damaged components. Wiggle the release fork to check for free play. These problems result in
slippage.
A broken motor mount (engine mount) can cause clutch slippage by allowing the engine to
move, binding the clutch linkage. Under load, the engine can lift up in the engine compartment,
shifting the clutch linkage and pushing on the release fork.
Grease and oil on the disc will also cause slippage. When this occurs, locate and stop and
leakage, thoroughly clean the clutch components, and replace the clutch disc. This is the only
remedy.
If clutch slippage is NOT caused by a problem with the clutch release mechanism, then the
trouble is normally inside the clutch. You have to remove the transmission and clutch
components for further inspection. Internal clutch problem, such as weak springs and bent or
improperly adjusted release levers, will prevent the pressure plant from applying even pressure.
This condition allows the disc to slip.
To test the clutch for slippage, set the emergency brake and start the engine. Place the
transmission or transaxle in high gear. Then try to drive the vehicle forward by slowly releasing
the clutch pedal. A clutch in good condition should lock up and immediately kill the engine. A
badly slipping clutch may allow the engine to run, even with the clutch pedal fully released.
Partial clutch slippage could let the engine run momentarily before stalling.
Note: Never let a clutch slip for more than a second or two. the extreme heat generated by
slippage will damage the flywheel and pressure plate faces.
2. Explain clutch Grabbing?
Grabbing:
A grabbing or chattering clutch will produce a very severe vibration or jerking motion when the
vehicle is accelerated from a standstill. Even when the operator slowly releases the clutch pedal,
it will seem like the clutch pedal is being pumped rapidly up an down. A loud bang or chattering
may be heard, as the vehicle body vibrates. Clutch grabbing and chatter is caused by problems
with components inside the clutch housing (friction disc) flywheel, or pressure plate. Other
reasons for a grabbing clutch could be due to oil or grease on the disc facings, glazing, or loose
disc facings. Broken parts in the clutch, such as broken disc facings, broken facing springs, or a
broken pressure plate, will also cause grabbing.
There are several things outside of the clutch that will cause a clutch to grab or chatter when it is
being engaged. Loose spring shackles or U – bolts, loose transmission mounts, and worn engine
mounts are among the items to be checked. If the clutch linkage binds, it may release suddenly to
throw the clutch into quick engagement, resulting in a heavy jerk. However, if all these items are
checked and found to be in good condition, the trouble is inside the clutch itself and will have to
be removed for repair.
3. Explain clutch Dragging?
Dragging:
A dragging clutch will make the transmission or transaxle grind when trying to engage or shift
gears. This condition results when the clutch disc does not completely disengage from the
flywheel or pressure plate when the clutch pedal is depressed. As a result, the clutch disc tends to
continue turning with the engine and attempts to drive the transmission.
The most common cause of a dragging clutch is too much clutch pedal free travel. With
excessive free travel, the pressure plate will not fully release when the clutch pedal is pushed to
the floor. Always check the clutch adjustments first. If adjustment of the linkage does not correct
the trouble, the problem is in the clutch, which must be removed for repair.

On the inside of the clutch housing, you will generally find a warped disc or pressure plate, oil
or grease on the friction surface, rusted or damaged transmission input shaft, or improper
adjustment of the pressure plate release levers causing the problem.
4. What are the abnormal noises noticed in clutch?
Abnormal Noises:
Faulty clutch parts can make various noises. When an operator reports that a clutch is making
noise, find out when the noise is heard. Does the sound occur when the pedal is moved, when in
neutral, when in gear, or when the pedal is held to the floor? This will assist you in determining
which parts are producing these noises.
An operator reports hearing a scraping, clunking, or squeaking sound when the clutch pedal is
moved up or down. This is a good sign of a worn or unlubricated clutch release mechanism.
With the engine off, pump the pedal and listen for the sound. Once the source of the sound is
located, you should clean, lubricate, or replace the parts as required.
Sounds produced from the clutch, when the clutch is initially ENGAGED, are generally due to
friction disc problems, such as a worn clutch disc facing, which causes a metal – to – metal
grinding sound. A rattling or a knocking sound may be produced by weak or broken clutch disc
torsion springs. These sounds indicate problems that require the removal of the transmission and
clutch assembly for repair.
If clutch noises are noticeable when the clutch is DISENGAGED, the trouble is most likely the
clutch release bearing. The bearing is probably either worn, binding, or, in some cases, loses its
lubricant. Most clutch release bearings are factory lubricated; however, on some larger trucks
and construction equipment, the bearing requires periodic lubrication. A worn pilot bearing may
also produce noises when the clutch is disengaged. The worn pilot bearing can let the
transmission input shaft and clutch disc vibrate up and down, causing an unusual noise.
5. What is clutch rattles?
Clutch Rattles:
This condition occurs when engine is idling with transmission in neutral causes are
1. Excessive clearance at pressure plate driving lags.
2. Anti Rattle springs or retractor spring on release lovers weak, broken or disconnected.
3. Looseness in clutch pedal operating linkages
4. Loose flywheel.
6. What are the causes for noise when clutch pedal is released? 1. Misalignment of
transmission with engine causing slight wobble of clutch disc hub.
Noticeable at engine idling or at low speed. 2. Disc hub loose fit on splined clutch shaft. 3. Disc
damper springs weak or broken. 4. No pedal play. 5. Weak or Broken pedal return spring. 6.
Weak or Broken Release sleeve spring. 7. Clutch linkage sticky 8. Clutch pedal sticky. 9. Clutch
release sleeve sticks.

7. What are the causes for clutch pedal is depressed?
1. Dirty, worn, damaged, broken or inadequately lubricates clutch release bearing. 2. Some
conditions as above for clutch shaft rear bearings or crank shaft spigot bearing.
Gear Box:

8. What are the Problems of gear boxes?
Slipping of gears at high 1 second gear (3 speed G. Eng)
1. G.B. mounting bolts loose.

Slipping of Gears at low / Reverse Gear 1. Fist / Reverse Gear Damaged 2. Improperly mated
splines of inside of first and reverse gear and / or external splines on
second and third synchronizer sleeve.
Sticking in gear:
1. Clutch not releasing completely. 2. Low lubricant level. 3. Corroded levers. 4. Tight main
driving gear spigot bearing. 5. Defective synchronizer sleeve. 9. What are the troubles with
fully synchronized gear boxes?
Troubles with fully synchronized gear boxes:
When diagonising gear noise note the gear position in which the noise occurs. Noise in all gear
position may be due to worn or damaged constant mesh gear box gears or bearing. Noise in only
one gear can usually traced to the particular gear involved other causes of noise are:
1. Misalignment due to loose mounting bolts. 2. Dutch housing misalignment 3. Diat or metal
chips in lubricant. 4. Not enough lube oil in G.B. 5. Improper Lubricant.
Noise in all gears:
1. Incorrect lubricant level. 2. Incorrect type of lubricant 3. Counter gear bearing worn or
damaged. 4. Counter gear worn on damaged. 5. Clutch gear bearing worn or damaged. 6. Main
shaft bearing worn or damaged. 7. Clutch gear worn or damaged. 8. Transmission misalignment
or loose. 9. Synchronisors worn or broken. 10. Main shaft gears worn or damaged.
Noise in reverse:
1. Reverse idler gear or shaft worn or damaged. 2. Reverse sliding sear worn or damaged. 3.
Shift linkage out of adjustment. 4. Shift linkage bent or damaged. 5. Shift linkage parts loose. 6.
Shift levers, shaft or forks worn.
Hard Shifting:

Jumps out of Gear:
1. Shift linkages out of adjustment. 2. Shift linkages bend or damaged. 3. Shift linkage parts
loose. 4. Shift levers shaft or fork worn. 5. Shift cover loose or gasket damaged. 6. Transmission
misalignment or loose. 7. Synchronizer worn or broken. 8. Clutch gear bearing retainer broken.
9. Clutch gear bearing worn or damaged. 10. Clutch spigot bearing worn or damaged. 11. Main
shaft worn or damaged. 12. Main shaft bearing worn or damaged.
10. Explain the various problems encountered in a propeller shaft?
Usually the problems that arise in propeller shafts are noise and vibrations which are the result of
incorrect universal joint angles, unbalanced parts or loose or worn parts. They may also arise due
to damaged propeller shaft tabes or material such as under coating stioking to the tube to cause
unbalance.
Checks:
The following checks should be made after a through visual inspection. Such an inspection gives
many dues like damages to the shaft tube, loose joints etc.
1. Chech the universal joint angle
2. Chech the propeller shaft run out
Run out near the joint should be less than 0.01 inches.
Run out in the centre of shaft should be less than 0.015 in.
A bent propeller shaft results due to accident which should be replaced.
Check the shaft for unbalance. It may be done in a garage.
3. Check looseness of all joints / parts. 4. Check every 600 miles that the four bolts holding the
propeller shaft to the rear axle are
tight.
Servicing:
The propeller shaft and universal joint servicing should be done periodically proper cleaning and
greasing of joints should be done carefully. In case the universal joints are fitted with grease
nipples – grease then every 3000 miles.
11. Write down the Trouble shooting of a propeller shaft?
Trouble Cause Remedy 1. Vibration and Noise
2. Noise occurring at standing. Start or during casting.
a. Brken or worn bearing of universal joint spider.
b. Distorted propeller shaft.
c. Unbalanced propeller shaft
d. Loose propeller shaft
a. Worn or damaged universal joint.
b. Worn propeller shaft position.
c. Loose propeller shaft.
d. Loose flanged xohe of universal joint.
Replace
Replace
Replace
Retighten
Replace
Replace
Retighten
Retighten

12. Explain the rear axle problems?
Noise when polling straight ahead:
1. Not enough oil. 2. Wrong grade of oil. 3. Poor quality of oil. 4. Excessive Backlash in crown
wheel and pinion. 5. Crown wheel (Ring Gears) and pinion worn. 6. Pinion shaft Bearings worn
of cease. 7. Excessive end play for pinion shaft. 8. Crown wheel and pinion misalignment due to
bent axle housing or distorted
differential case. 9. Ring gear (crown wheel) warped. 10. Differential bearings worn or loose. 11.
Ring gear rivets or screws loose. 12. Non matching ring gear and pinion. Knocking or clicking:
1. Flat spot on ring gear or pinion tooth or tooth chipped or metal lodged on tooth.
2. Flat spot on bearings.
3. Loose axle shaft keys.
4. Loose splined shafts
5. Mismatched differential case halves.
Intermittent noise:
1. Warped Ring Gear.
2. Loose Ring Gear Rivets or Screws.
3. Ring Gear improperly installed on differential case due to dirt or Burs between the two.
Noise on turns:
1. Differential planet gears or sun gears chipped broken or scuffed.
2. Planet gears (differential) Binding on pinion shaft.
3. Differential gears (planet or sun) Become loose due to worn usefulness though wean
bushing or shaft.
4. Excessive backlash between differential gears.
5. Excessive Axle shaft and play.
6. Contact surfaces between differential sun gears and case burred. Scored or damaged.
Vibrations:
1. Rough rear wheel bearing 2. Unbalanced or damaged propeller shafts. 3. Type unbalances. 4.
Worn universal joint in propeller shaft. 5. Incorrect drive line angle. 6. Improperly indexed
propeller shaft at companion flange. 7. Companion flange run out too much.
Oil leakage at axle ends:
1. Oil level too high. 2. Oil too light or poor quality. 3. Axle shaft oil seals worn. 4. Axle shaft
bearing retainer loose 5. Cracked Reoa Axle housing. 6. Vent (if provided) clogged.
13. What are the reasons for hard steering?
1. Low or uneven type pressure. 2. Steering gear or connections adjusted too tight. 3. Insufficient
or incorrect lubricant used. 4. Excessive castor. 5. Suspension arms bent or twisted. 6. Front
spring sagged. 7. Frame bent or broken. 8. Steering knuckle bent. 9. Kingpin frozen in bushing.
10. Excessive misalignment or steering shaft coupling. 11. Misalignment or steering column and
gear.
14. What are the causes for excessive play or looseness of steering?
1. Gear connections adjusted loose or worn. 2. Steering knuckle bushing worn. 3. Front wheel
bearing improperly adjusted or worn. 4. Worn Ball joints. 5. Worn or loose steering shaft
bearings. 6. Worn control arm bushing. 7. Steering wheel loose on shaft. 8. Loose linkage. 9.
Excessive backlash. 10. Worn intermediate rod or tie – rod 6ockets.
15. What are the reasons for poor returability?
1. Front End Need Lubrication. 2. Too Tight adjustment of steering Gear. 3. Front End
Alignment of steering Gear. 4. Misalignment of steering gear to column.

Rattle or chuckle in steering gear:
1. Insufficient or incorrect lubricant. 2. Excessive Back lash 3. Worn or loose shaft bearing. 4.
Pitman Arm or Drop Arm Loose on shaft.
16. What are the causes for erratic steering on application of brakes?
1. Oil or brake fluid on lining. 2. Improperly adjusted brakes. 3. Weak spring at front 4. Low or
uneven tyre pressure. 5. Insufficient or uneven castor. 6. Bent steering knuckle. 7. Shift linkages
out of adjustment. 8. Shift linkages bend or damaged. 9. Shift linkage parts loose. 10. Shift levers
shaft or fork worn.
17. What are the reasons of vehicle pulls to one side?
1. Low or uneven tyre pressure. 2. Incorrect or uneven castor or camber. 3. Improperly adjusted
wheel bearings. 4. Uneven front height of vehicle. 5. Incorrect Toe – in. 6. Oil or brake fluid
inclining. 7. Unevenly adjusted Brakes. 8. France Bent or Broken. 9. Rear wheels not cracking
front wheels. 10. Loose u – bolts or sheared centre bolt of rear springs. 11. Broken or weak rear
springs.
18. What is steering wandering?
Tendency of a can to veer away from a st Para without driver control frequency steering
movement is necessary.
Low or uneven tyre pressure.
Normal drng:
Lack of tracking means the run with are not following a page
When braking:
When the brake shoes are unevenly adjusted or when a stucn w cylinder or caliper piston cases
the shoes at one w to apply less broking 19. What is steering kick back?
Steering shock – consist of sharp of rapid movement of the steering w that occur when the front
w encounter obstruction in the road, incurred tyre inflation.
Noises:
Rating (connected with suspension system.
20. What are the reasons for long pedal travel or pedal goes up to floor level?
S.No Causes Remedy 1 2 3 4 5
Excessive clearance between linings and drum
Weak hose. (Bulging the hose)
Leaking wheel cylinders.
Leaking in master cylinders
Leaking stop light switch.
Adjust brakes
Replace with new
Service with repair kit
Service with repair kit
Replace
6
8
9
Air in hydraulic system. [ Farest wheel cylinder]
Blocked master cylinder cap end hole.
Low fluid level in master cylinder
Wear of brake pedal bush

Bleed the system.
Clean or replace
Clean or replace
Replace.
21. What are the reasons for spongy pedal and write down the remedies.
S.No. Causes Remedy
1
2
3
4
5
6
7
8
9
Air in hydraulic system
Improper lining excessive between lining and shoe
Distorted shoes.
Bell mouthed, worn out, weak or cracked drums
Clogged master cylinder, filter cap, vent hole
Weak hose
Weak cylinder (master) mounting.
Bent master cylinder push rod and clevis bent
Unbedded linings (lining not in full contact)
Bleed
Reline
Replace
Replace the drum
Clean or replace and bleed
Replace
Check and strength master ness
cylinder
A place push rod and dews
Bed linings.
Brakes pulling (vehicle pulls to one side)
S.No Causes Remedy 1. Uneven adjustment of brake Adjust all the brakes evenly. 2. Tyres
improperly inflated.
Inflated to recomerenced for feelence with
recommended grade of lining all 3. Tyre tread unevenly worn on either
side or different
Replace with recommended grade of lining
all
4. Grease fund soahed living on brake
opposite to the direction of pulling.
Replace lining after remedying the causes of
grease or thick leak 5. Linings of difference grades an either

side of brake
Replace with recommended grade at linings
all rounds 6. Unbedded linings Bed linings 7. Shoes wrongly fitted Install loading and traviling
shoes correctly. 8. Rivers loose in lining River properly 9. Wheel cylinder pistons seized Service
or replace wheel cylinder. 10. Wheel cylinder diameter different on
opposite side
Replace with correct cylinder.
11. Clogged on restriction in hydraulix
hose or pipe
Clean and replace pipe line
12. Weak a broken shoe return springs Check and replace weak open coiled or
checked springs 13. Drums oval or eccentric True up or replace 14. Loose back plate mounting
bolbs, loose
shoe abutment or adjuster housings
Tighten back plate mounting bolts and
adjuster housing mountings. If abutment is
loose replace back plate. 15. Improper steering Geometry Reset 16. Loose or worn tie rod end
Tightener replace 17. Loose king pin and bushes Replace as a set 18. Loose wheel bearing,
steering or a
clamp nuts
Adjust or tighten
19. Weak shock absorber Replace
22. What are the causes and remedies of Brake fade?
Brake fade: Fade is a temporary reduction of brake effectiveness resulting from heat.
1. Incorrect grade of lining Replace with proper grade 2. Distorted shoe Replace 3. Overload
vehicle Reduce reload 4. Drafting brakes Adjust (or) rectify the problem 5. Thin drums Replace
6. Contaminated third Orange the fluid 23. What are the causes and remedies for
1. Back plate bend or shoes
slightly twisted
Replace parts
2. Metallic parts (or) dust
embedded in lining
Band paper the lining and
drum and remove metal
particles if any (or) replace
timings down if necessary. 3. Loose rivers (or) linings not
hold evently against shoe
rim/gab bet lining & shoe rim)
Reline shoe properly
4. Drum not true, weak (or)
distorded
True up (or) replace drums.
5. Incorrect grade of lining Replace lining with
recommended lining. 6. Shoe scrapping on back plate
shoe pad
Lubricate shoe pads with high

melting point graphite grease 7. Weak (or) Broken hold down
spring
Replace defective parts
8. Loose wheel bearing Adjust bearing 9. Loose back plate (or) wheel
cylinder
Tighten
10. Over adjusted steady post Adjust properly 11. Glazed lining Surface lining with sand paper
12. Highly polished drum Skim down 24. What are the causes and remedies for when
Braking?
Shapping noise in the front end:
1. Deep grooves in back plate shoe
pads
Replace back plate
2. Lack of lubricate in moving parts Lubricate all moving parts on the back
plate with high melting point 3. Loose drum (or) back plate Graphite greasts tighten 4. Loose (or)
worn out front end
parts m ) thumping
Tighten (or) replace defective parts.
1. Loose back place, drum (or) axle
is bolts
Tighten
2. Grabbing lining Replce with recommended
grade of lining
3. Shoe releasing spring unequal
wear
uneven brake drum inner
diameter
Replace spring
Shim the down (or) wep tera
25. What are the causes and remedies for Grinding noise in braking?
1. Shoe vim foaling with the
drum
Check shoe retracting springs
for correct fit
2. Weak shoe hold down spring
(or) bent pint
Replace parts
3. Bent shoe web Replace shoe 4. Foreign material in lining Remove & replace lining 5. Worn
out (or) broken lining Repalce with lining kib, skim
(or) replace
6. Rough drum surface Drum it scorced skim drum 7. Improper adjustment of steady
past
Adjust properly.
Body Maintenance:
26. Explain the procedure for servicing the wheel cylinder of braks?

Install all the other components with the wheel cylinder and fin it on the wheel.
Bleed the system to remove air.

1. Pedal does not return fully Lubricate (or) recondition
pedal shaft & bushers. 2. No clearance but push rod
and master cylinder piston
Adjust brake pedal free play
3. Improperly adjusted service
brake (or) hand brake
Check & adjust
4. Recuperating and feed port Service master cylinder
clogged in master cylinder 5. Swollen seals Flush the system and replace
all rubber parts
6. Seized wheel cylinder piston Cylinder services (or) replace
wheel cylinder
7. Improper Brake fluid Replace 8. Weak (or) Broken shoe
return spring
Replace
9. Blocked filler cap and hole Clean (or) replace the cap.
28. What are the causes and remedies for one wheel drag?
1. Weak or broken retracting springs Replace the springs 2. Clearance between shoe & drum to a
small
in a wheel
Adjust
3. Loose wheel bearing Adjust 4. Wheel cylinder cup seals swollen & piston
seized
Service with kit
5. Excessive ovality of drum True the drum clean and flush 6. Obstructed hydraulic Replace
shoes 7. Distorted shoes Replace with proper linins 8. Incorrect grade of lining 9. Draging of
Rear brake Adjust 10. Mal adjustment Lubricate & 11. Parting Brake cable seized adjust
29. What are the causes and remedies for hard pedal or poor braking?
1. Causes Remedy 2. Incorrect linning Adjust properly 3. Grease or oil soaked lining Replace 4.
Un bedded living Bed lining properly 5. Glazed lining Sand paper the lining surface 6. Pedal
binding on the shaft Lubricate (or) condition 7. Seized master cylinder or
wheel cylinder discon
Service with kit.
8. Wrongly fitted shoes Install leading & trailing shoes
correctly
9. Bell mouthed barrel shaped
(or) polished drum
Replace (or) reborb the down.
30. What are the causes and remedies for reduced brake pedal travel?
S.No Causes Remedy 1. Master cylinder recrepeting
hole blocked
Service the master cylinder 2. Swollen cup seal in master
Flash the system and replace

all insber pads. 3. Weak shoes retracting spring Service & replace inserted part 4. Wheel cylinder
Replace the spring 5. Lining swelling Replace lining. 31. What are the causes and remedies
for Judden in brake pedal?
1. Excessive ovality of drum True the drum 2. Loose drum on hub Tighten 3. Worn (or) loose
bearing Replace or adjust 4. Rusty drum De rust (or) replace
Batteries which are not too badly sulphate may often be reconditioned by charging at a
very low rate from
1
5
to
1
10
their normal charging current. The charging should be continued until
the battery begins to gas freely when it should be discharged through high resistance at about
1
3
to
1
4
ampere note.
Other battery troubles which may occur are internal short circuiting of the plates due to the
For charging the battery the instructions of the manufacturer are to be strictly followed. A
battery in good condition can be given a rapid or boost charge such that it is charged in
1
d
to 1
hour . The acid temperature should not exceed 110 F during this, process.
For the regular maintenance of the battery the following equipments instruments and materials
and required.
i) Battery charger
ii) Hydrometer
iii) Voltmeter with loading resistors
iv) Distilled water
v) Acid solution (H2SO4)
vi) Terminal cleanser
vii) Wiping cloth etc
Maintenance of the vehicle tyres:
Automobile types are costly items and are subjected to rapid wear maintained properly periodic
inspection for the correct inflation pressure, wheel alignment, toe-in, camber, etc, will prolong
the life of the tyre. For removing a tyre with tube, the tube is first deflated and then both the
beads are pushed off then rim seatings with a tyre lever. The bead on the valve side should be
first loosened with a tyre lever and pushed in to the rim well on the opposite side of the wheel to
the valve. Using a second tyre lever, about 2” away from the first the bead should be prised over

the rim and then the rest of the bead will readily come over the rim. When a tube is inserted into
its cover, it should be slightly inflated before attempting to replace the tyre bead in position.
Excessive or irregular tyre wear can be due to several different causes which includes.
(i) In correct inflation pressure (ii) Wrong steering mechanism geometry (iii) Incorrect camber,
castor and toe-in (iv) Bad driving of the car (v) Unbalanced wheel and tyre (vi) Worn stearing
mechanism and king pins.
The tyre inflation pressure depends upon the size of the tyre, the load on the tyres and the
maximum speed at which the vehicle is driven. Some causes of excessive tyre wear
(a) Under inflation
(b) Over inflation
(c) Excessive camber
(d) Excessive toe-in
If the tyre pressure is much lower than the correct value, then the type walls will flux more and
greater stress will occur on the type cords, causing, greater heat to on the weaken the casing .
The result will be uneven wear on the read, reduced vehicle performance, greater roll on curves
and higher fuel consumption. There will be greater tread contact area with the ground.
The higher inflation pressure causes greater tyre chord stresses and increased wear on the centre
of the tread. It also tends to reduce the further over inflated tyre is more susceptible to cuts and
brusises.
Excessive wheel camber will cause greater wear on the outer ribs of the tyre. For excessive
negative camber the inside tyre ribs will wear more.

If the toe-in is greater than the correct distance given by the manufacturer, then the front wheel
tyre will develop fins on the outside edges which will shorten the tyre life. If the front wheel
have too much toe-out the tread ribs will shown fins, but on the opposite sides of the ribs.
If a car with correct camber angle is regularly driven on a well cambered road the left hand front
tyre will tend to wear more than the other tyres.
Severe acceleration, breaking, steering action and springing movements will cause irregular
spotty wear on the front tyres as if they were tonehed in places with high speed grinding wheel.
When a vehicle wheel, driven at moderate speed strikes the side of a road kerb or any other solid
object the impact will often fracture the tyre casing chood, with the result of a later tyre fail by
blow ow.
If the wheel unit is out of balance, road shocks of a vibratory kind known as tramp and steering
shimmy may occur. The forms is due to wheel unbalance in the radial sence and the latter due to
unbalanced region out of centre.
When the complete tyre and wheel is tested for balance, the lighten side of the wheel is revealed
and the correct balance is effected by placing lead weights specially designed for the purpose, on
the rims lighter side.
The rate of tread wear increases fairly rapidly with the vehicle speed. The following figures by
the Dunlop Rubber company emphasigs this
Average speedMileage obtained

Other factors affecting tyre wear include condition of road surface, road curves and graduals,
and temperature. The rate of wear on warm, roader is twice to that if cold roads.

Method of sealing small punctures of tubeless tyres with rubber sealing plug.

Method of changing tyres around to obtain maximum mileages

Method of adjusting valve stem clearance of OHV Engines
A useful valve facing tool
Figure: Mechanic toe gauge used to measure the distance between the centres at the front
and back of the tires. The difference is distances is the total toe (Mutsubishi Motor Sales of
America. Inc) Of frame bracket. When the shims are inside the frame bracket (Figure) adding
shims moves the

Adding shims at one bolts and removing from the other moves the outer end of the uppercontrol
arm forward or backward. This increases or decreases caster figure:
Note:Some trucks have an I-beam front axle and leaf springs (figure) instead of upper and lower
control arms. Caster is adjusted by installing tapered caster shims between the spring and the
axle. If the shims are installed backward, the axle will have excessive negative caster. The drive
may complain of difficulty in keeping the truck in a straight-ahead position, wander and pull.

2. Cam-Bolt Adjustment Figure shows one arrangement using offset or eccentric cam bolts to
adjust caster and camber. The two bushings at the inner end of the upper control arm attach to
the frame brackets with two cam bolts. Tuning the cam bolts the same amount in the same
direction changes camber. Figure: Caster and camber adjustments on some vehicles using
shims (Chevolet Division of General Motors Corporation).

Turning only one cam bolt or turning both cam bolts in opposite direction changes caster. On
some vehicles , the cam bolts are in the inner ends of the lower-control arms.

Figure: Caster and camber adjustments by turning offset, or eccentric, cam bolts (ATW)
3. Pivot-Shaft Adjustment This arrangement has slots in the frame at the two points where the
upper control-arm pivot shaft attaches bolts and moving the pivot shaft in or out changes camber.
4.Struct-Rod AdjustmentChanging the length of the suspension strut rod changes caster .
Turning the cam bolt on the inner end of the lower control arm changes camber. Caster and
Camber Adjustments (Strut suspension).
Many vehicles with MacPherson struts do not have camber and caster adjustments. Other have a
cam bolt at the lower end of the adjust camber.(Figure). Turning the cam bolt moves the top of
the wheel in or out. If no camber adjustment is provided, some manufacturers recommend

enlarging the bolts holes in the bottom of the strut. On some MacPherson strut Suspensions,
caster and camber are adjusted at the upper strunt mount (figure) Moving the strut toward the
front or rear changes caster. Moving the strut in or out changes camber.
Toe Adjustment:
After making caste rand camber adjustments, check and adjust toe. Front wheel toe is measured
with the steering wheel centered and the wheels straight ahead. Figure shows a mechanical too

gauge that measures total toe. Its length is adjusted so the pointers are at the centers of the tires.
The total toe is the difference in distance between tire centers at the rear and at the front.
To adjust toe, loosen the tie-rod locknuts (figure) Rotate the rods until the toe measurement is
set to specifications. Do not allow the boots on the ends of the steering gear to twist while
making the adjustment. Then tighten the tie –rod locknuts to the specified torque.
Steering- Wheel Centering
When all four wheels are properly aligned and there is not thrust angle, the steering wheel will
be centered while the vehicle is moving straight ahead (figure). If not, the steering wheel can be
centered by adjusting the tie rods. Adjust the tie rods to steer the front wheel in the same
direction the steering wheel is off center. For example, if the steering wheel is off center to the
right, adjust the tie rods to make the front wheels steer toward the right.
To make the adjustment, loosen the locknuts and turn both tie rods the same amount in the same
direction. (Figure). On one car, only 1/5 turn of the tie rods moves the steering-wheel rim 0.250
inch [6 mm] or 2 degrees.

Caster Adjustment slide the upper plate toward the front of car until the desired caster reading is
obtained. Camber Adjustment slide the Large Lock nut toward or away from the Engine until the
desired camber reading is obtained.
Figure: Adjusting caster and camber on a MacPherson strut by repositioning the upper
strut mount (Moog. Automotive, Inc).
Figure: Adjusting to by changing the length of tie rod (Chrysler Corporation).

Figure: Tie rod adjustments to center the stering wheel (Chrysler Corporation).
Rear-Wheel Alignment:
Many front-wheel drive vehicles have stub axles or spindles on which the rear hubs and wheels
mount. Rear wheel camber and too may be adjustable. Rear-wheel caster is usually set to zero
and is not adjustable. Rear-wheel caster is usually set to zero and is not adjustable. Various
methods of adjusting rear-wheel camber and toe are described below. Refer to the vehicle service
manual for rear-wheel alignment procedures on specific vehicles.

1. Adjusting Rear-Wheel Camber in some vehicles, camber is adjusted by turning a cam bolt
in the inner end of the lower-control arm or spindle-support rod. On other vehicle, shims placed
between the spindle and the mounting plate provide the camber adjustment.

Figure: Adjusting rear-wheel camber by turning a cam bolt in the inner end of the lower-
control arm, or spindle support rod. (Chevrolet Division of motors Corporation).

Figure: Using shims to adjust rear-wheel camber and toe, adjustments at the left-rear
wheel are shown. (Chrysler Corporation).

(a) Adjusting control arm postion
Figure: Adjusting rear wheel toe by (A) adjusting control arm position and (B) shimming
the trailing arms. (Buick Division of General Motors Corporation, Dana Corporation)

PART – A
1. Explain the importance and various features of battery maintenance.
Maintenance of the vehicle battery
Most of the vehicles use the lead-acid battery using separate packs of positive and negative
plates immersed in a solution of sulphuric acid.
The battery must be properly maintained at all times, since any failure of it will put the vehicle
out of action. The various maintenance item for a typical battery are illustrated in the figure.
The electrolyte solution of the battery is mark by adding gradually 1 volume of commercial
sulphuric acid of 1.835 density to 3 volumes of distilled water to give a final cool solution of
check 1.28 to 1.29 density of the electrolyte at fully-charged, half charged and completely,
discharged conditions are 1.28 to 1.29, 1.19 to 1.21 and 1.11 to 1.13 respy: all at 80o F.
The acid density is frequently checked with a hydrometer, which consists of an outer glove tube,
with a rubber to dip into the acid and an inner calibrated glass float to read the acid density.
Lower reading from any one cell of the battery indicates a faulty cell.
The acid level is to be kept just above the top of the plates. If the level drop through evaporation
as in hot weather or through are charging, distilled water n to be used to bring up the acid level.
However if the level falls during charging when the acid is splashed out due to gassing, or the
acid accidentally spilt, fresh acid solution is to be used. When the vehicle is in used, the battery
should be checked and of necessary topped-up every month or so.
2. Draw the cut section view-of a battery and the maintenance activities or each component.
Figure:

Voltage of the battery measured across its terminals cannot indicate the condition of the battery,
under a special form of voltmeter which apphes an electric load by means of shunting resistance
which taken a heavy current discharge for a short time is used. A fully charged battery cell
should read 215 to 2.2 volts otherwise it is defective.
The battery should never be left in a semi-or fully discharged condition for long. It is advisable
to give the battery an occasional charge when the car is not used. Of the vehicle is to be laid up
for a long period, the battery can be stored by the dry method. To do this the battery is first fully
charged and then the electrolyte drained out. The pitch seal is removed with the aid of a hot iron
and the wooden separators taken out, dried and stored in a dry place. The battery plates are also
dried. When the battery is again required, it is reassembled, filled with electrolyte and charged.
Every twelve months when in normal use, empty out the electrolyte, wash out the sediments
from the sediment wells with distilled water and refill with fresh electrolyte and charge.
The battery terminates must be kept clean from the corroded products, otherwise it will act as a
insulator. For this terminals can be coated with Vaseline or thick grease.
A white deposit formed on the plates in an indication of the neglect of the battery. This is due to
sulphation, lead sulphate being formed.
Batteries which are not too badly sulphated may often be reconditioned by charging at a
very low rate from
1 1
to
5 10
. Their normal charging current. The charging should be continued
until the battery begins to gas freely when it should be discharged through high resistance at
about

1 1
to
3 4
ampere rate.
Other battery troubles which may occur are internal short circuiting of the plates due to the
breaking away of the paste from the plates and its lodgement between the plates and buckled
plates due to excessive vibration or constant overchanging.
For charging the battery the instructions of the manufacturer are to be strictly followed. A
battery in good condition can be given a rapid or boost charge such that it in charged in
1
to 1
2 hour. The acid temperature should not exceed 110o F during this process.
3. What are the equipment required for battery maintenance.
For the regular maintenance of the battery the following equipments, instruments and materials
are required.
(i) Battery charger (ii) Hydrometer (iii) Voltmeter with loading resistors (iv) Distilled water (v)
Acid solution (H2SO4) (vi) Terminal cleanser (vii) Wiping cloth etc.
4. What are the causes for self state starter not tuning up? Explain briefly.
If the lights become dim or go our when the starter switch is closed, the battery maybe too weak
to operate the starter. In this case a push start is needed. Cars equipped with alternators cannot be
push started if the battery is complete dead because alternators retain no residual magnetism.
Due to starter circuit
1. Low battery 2. Connections loose, dirty, corroded or broken at battery terminals, starter switch
terminal or
battery ground strap. 3. Short circuit across starter terminals. 4. Neutral start switch out of
adjustment or defective.
Due to starter switch
1. Starter switch stuck 2. Defective solenoid 3. starter switch makes poor contact due to dirt,
corrosion, bent parts or weak spring 4. Starter switch fails to close circuit because of sticking or
broken contact part 5. Neutral safety switch out of adjustment or defective. Due to armature
and field circuits
1. Armature winding burned out, shorted, grounded or open circuited. 2. Field coils burned out,
shorted or grounded. 3. Broken wire in armature winding or brush pigtail lead 4. Broken wire in
field winding or broken lead 5. Loose dirty or corroded connections in field circuit.
Due to commutator and brushes
1. Brush pigtail leads loose or broken 2. Starter brushes cracked crosswise 3. Arm type brush
holder sticks 4. Brush sticks in sliding brush holder 5. Bent brush holder causes poor contact 6.
Starter brushes worn badly 7. Brush leads shorted or have loose, dirty, broken or corroded
connections 8. Poor brush contact due to weak or broken springs 9. Brushes coated with oil 10.
High (Raised) Mica between commutator serviced prevents brush contact. 11. Commutator bars
loose and or solder melted. 12. Commutator dirty, corroded or broken
Due to engine resistance
1. Piston sticking to cylinders in overheated engine 2. Piston stuck to cylinders due to gummy oil
3. Jamned generator armature 4. Combustion chamber full of water 5. Sold ICE in water pump 6.
Broken engine moving parts 7. Due to cold weather and too heavy oil
Due to armature binding

1. Loose field poles 2. Armature shaft frozen in bearings 3. Loose end plates 4. Windings thrown
out of armature slots 5. Armature locked magnetically to field poles because of loose bearing or
worn / beat shaft 6. Bendix spring retaining screen loose and jammed against housing 7.
Cracked/Distorted drive housing 8. Starter misaligned 9. Jamming due to burredteeth on pinion /
Ring gear 10. Starter pinion (sliding gear type) Jams due to incorrect endwise clearance. 5. What
are the reasons for high engine oh consumption.
1. External oil leaks 2. Leaky piston rings (Due to wear) 3. Leaky piston rings (Due to sticking
caused by gummy Deposits. Free the rings with
suitable solvent). Blue smoke indicate badly leaking rings. 4. Worn piston and cylinders 5.
Cylinder block distorted by Tightening cylinder head bolts unevenly. 6. Excessive clearance
between valve stems and guides. 7. Worn main bearing / conrod bearing. 8. Oil pressure too high
(wrong setting of oil pressure relief valve or clogged relief passage) 9. Loose piston pins 10.
Grade or oil too light (Hard driving on hot day will also consume more oil) 11. Clogged crank
case ventilation system 12. Intake manifold leak together with valve door gasket leak 13. Oil
level too high 14. Piston ring gaps not staggered 15. Incorrect ring size 16. Piston rings out of
round broken or scrod 17. Ring lands damaged 18. Ring grooves damaged and rings struck in
ring grooves.
6. What are the reasons for frequent changing of a battery?
Battery requires frequent charging
Insufficient current flow to battery
1. Defective generator / Alternator 2. Incorrect Voltage regulator setting 3. Regulator contacts
oxidized or burned 4. Sulphated battery 5. Corroded battery terminal 6. Regulator not grounded
7. Slipping fan belt, 8. Loose connections/Grounds in lighting or ignition circuits 9. Blown
regulator fuse 10. Wrong size generator drive pulley 11. Shorted or open alternator rectifiers 12.
Grounded stator wire in alternator.
7. What are the reason excessive starting load causing abnormal current flow from battery.
1. Frequent use of starter motor. 2. Excessive use of starter motor (difficult starting) 3. Faulty
starter motor 4. Excessive engine friction 5. Excessive lighting loads 6. Abnormal accessory
loads 7. Internal Discharge of battery
8. Write down the steps involved in servicing the ignition systemwith contact points.
1. Clean, Regap or replace spark plugs 2. Clean and inspect the ignition coil if the tower (TOP) is
cracked replace the coil 3. Replace the primary wire (coil to treasure 4. Clean and inspect the
distributor cap 5. Examine the rotor 6. Twiss the distributor seat in are of rotation and reliable it
mechanical must be repaires. 7. Inspect the contact points replace then is necessary, check and
set the cap. 8. Put a small amount of 9. Check and set the dwell using dwellmete 9. List out the
causes for the ignition systemtroubles and causes.
Engine misfire at all speed
1. Defective plug wires 2. Cracked distributor CAP. 3. Fouled spark plug 4. Burned valves
Engine Misfires during acceleration
1. Detective plug wires 2. Fouled or worn plugs 3. Burned contact points 4. Partially shorted
ignition coil 5. Open capacitor 6. Poor primary circuit 7. Carburetor problems
Engine Misfires At High Speed:-
1. Insufficient Dwell angle 2. Carburetor Problems
Hard Starting: 1. Burned contact points. 2. Improper Ignition timing 3. Defective Ballast
Resistor 4. Low Battery 5. Poor chohe action 6. Open capacitor 7. Ignition timing too much
Advanced

10. Ignition timing too much Advanced enumerate the starting system problems and their
causes.
Battery not holding charge
1. Internal Deffect of the battery Electrolyte op.gravity under fully discharged 1.28 STP
20oC.
Short circuit Antimony Green 3. Sediment at Bottom short circuit 4. Sulphation.
Gel Electrolyte
1. Sulphation Under certain condition Sulphbe is former
Hard nature
Subsequent penetration at electrodyle.
3. Electrical Leakage / Shorts 4. Excessive Electrical usage with car stopped / idling 5. Battery
not used for long periods.
Battery uses excessive water
1. High voltage Regulator setting 2. Sulphated Battery 3. High Temperature
11. Briefly mention the charging systemproblems and causes.
No change rate
1. Defective alternator / Generator 2. Defective voltage regulator 3. Open or grounded field wire
4. Open circuit 5. Worn or stock brushes DC – Generator – cutout necessary Ac – Alternator – In
built Rectifier Welding Transfer – Selenium Rectifier – 1 wayflow mercury rectifier.
1. Alter nor or Generator 2. Rectifier 3. Cables 4. Battery 5. Drive bolt
Low charge rate
1. Regulator out of adjustment 2. Defective Regulator 3. Excessive field circuit Resistance 4.
Defective Alternator / Regulator 5. Worn Brushes 6. Sulfated Battery
High charge Rate
1. Regulator out of adjustment 2. Defective Regulator 3. Defective Battery 4. High Battery
Temperatures 5. An accessory drawing excessive current even when the engine is not running.
12. Explain all the reasons for engine not starting up.
Due to open primary circuit
1. Burned or oxidized ignition points 2. Ballast Resistor burned or open 3. Ignition points not
casing. 4. Breaker arm binding on pivot post preventing closing of points. 5. Breaker arm spring
weak or broken 6. Breaker arm distorted or bent 7. Dirty Ignition points. 8. Primary lead
connection loose 9. Primary winding open 10. Open ignition switch circuit Due to short
circuited primary circuit
Grounded primary coil winding grounded ignition switch or a lead will causes wires to burn.
Possible causes for grounded primary circuit:-

1. Ignition points not opening or closing due to improper adjustment. 2. Ignition points not
opening due to worn rubbing block on breaker arm. 3. Faulty insulating bushing on breaker arm.
4. Cracked or faulty insulator at distributor primary terminal. 5. Grounded condenser 6.
Distributor to coil lead grounded. 7. Primary coil winding grounded.
Due to faulty secondary ignition circuit
1. Corroded spark plug cable terminals 2. Cracked insulation or cables 3. Ignition coil weak or in
operative 4. Moisture on Ignition coil terminals distributor cover spark plug pordains or on
distributor. 5. Improper type of spark plugs 6. Cracked distributor cap or burned carbon brush in
the cap. 7. Improper connection to spark plugs (Not correct as per firing order) 8. Spark plugs
damaged dirts or wet porcelien cracked or gaps improperly adjusted 9. Rotor contact spring bent
or broken 10. Distributor rotor grounded. 11. Distributor cap centre terminal broken or missing.
Due to battery
1. Battery run down 2. Terminal loose or badly corroded 3. Improper ground 4. Battery cable
undersize
Due to excessive fuel supply (flooding)
Accumulation of liquid fuel in the intake manifolds as well cylinder. The engine won’t start until
the rich mixture formed by flooding is pumped out. 13. Explain the procedure for servicing of
the distributor.
1. Remove the distributor cap by snapping the hold down clips 2. Inspect the cap wipe inside of
the cap cracked chipped or carbon tracked caps must be
replaced. 3. If any of the metal terminal is broken or badly burned, replace the cap slightly
corroded or
blackened terminals can be cleaned with fine sand paper. 4. Remove the rotor visually check for
cracks, burning or corrosion of the metal tips or
mechanical interference with the cap. 5. Check mechanical advance springs and counter weights
turn the upper half of the
distributors shaft in the direction of rotation release the shaft it should snap back if sluggish
the springs are to replaced 6. Check the vacuum advance by pressing you finger against the
contact breaker assembly
and moving the base plate in the direction opposite to the shaft rotation the base plate
should swivel with out binding. 7. Inspect the contact points for build-up and crater spots
alignment, colour and weak direct
may be cleaned with a few strokes of a fine cut contact point file blue burkes points
indicates a bad capacities it is customary to replace capacities. 8. Test the vacuum advance 9.
Check distributor contact points and clean them. 10. Re-install distributor cap and replace wiring.
11. Check battery state of charge water level and hold down clamps. 12. Check battery cables for
damage, corrosion and loose connections. 13. If the battery is over charged or undercharged
check the dynamo (Alternator) and regulator 14. Check drive belts and tighten or replace them as
required. 15. Check the intake manifold bolts for tightness to proper specifications even a slight
leak will
reduce engine performance. 16. Check fuel lines for tight connections. 17. Check the weekly for
leak 18. Check and accelerator linkage 19. Check crank case ventilation system. 20. Remove
carburetor air cleaner and check choke valve clean or replace air filter element if
necessary. 21. Check and adjust contact point dwell and ignition timing. 22. Adjust idle shed and
mixture 23. Check the lube-oil dipstick level 24. Check the working of lights and horn. Adjust
the head lamp for proper focusing. 25. Check steering system for easiness.

14. What are the various electrical testing equipments required for an automobile
workshop.
Ignition System 1. Power timing light
ves on .
2. Dwell meter:-
3. Voltmeter:-
4. Ammeter:-
sure the current
5. Ohmmeter:-
For Electrical System
1. Voltmeter 2. Ammeter (0-80 Amps). 3. Tachometer 4. Hydrometer 5. Battery load Tester
Battery load Test done an automotive.
Hydrometer (To check the specific gravity of Electrolyte for a specific Temp)
Eg.1.28 at 20oC.
Open volt test
Each cell have 2.1 volts
Cadmium Test
High current Test
Starter motor register is 300 amps for cracking the engine.
PART – A
1. Write down the Maintenance of the fuel injection Sequential system?
Fuel Tank
Feed Pump:
Check rubber sealin
Filters
Fuel Injection Pump:-
ure pipes.
2. Write the cooling systemproblems and causes?
Problem:
- 85 C
Normal Reasons for Engine overheating:

mproper lubrication (High engine friction)
Cooling System problems and Causes:
Engine Overheating:
1. Loss of coolant 2. Defective thermostat 3. Defective water pump 4. Collapsed radiator hose 5.
Excessive Rust and seales 6. Obstructed Air passage Through Radiator 7. Late Ignition Timing
8. Combustion leak in to cooling system 9. Improper coolant Mix 10. Defective Temperature
Gauge
Engine Runs Too Cool:
1. Defective Thermostat 2. Defective Gauge
3. Write down the fuel systemproblems and causes?
Fuel System problems and causes:
Carburettor flooding:
1. Worn needle and seat 2. leaky float 3. Excessive fuel pump pressure 4. Improper float
adjustment. (In olden days tickler mechanisms)
Rought Idle:
1. Improper Idle mixture 2. Poor compression 3. Intake manifold leak 4. Defective spark plug
wires 5. Cracked Distributor cap 6. Stuck PCV valve
Stumbling During Acceleration:
1. Defective Accelerator pump 2. Improper Adjustment of Acc. Pump
3. Ignition misfire
Sluggish Performance:
1. Late ignition Timing
2. Tool rich or too lean mixture
3. Defective Advance mechanism
3. How will you check the cooling system?
Cooling system checks & test:
Check the coolant level. If it is low min the proper solution of antifreeze and water in an
antifreeze container and fill it to the specified level
Check the strength of antifreeze solution by wing either float hydrometer or a ball
hydrometer.
Float hydrometer:
Place the end of the rubber tube into the coolant sequeeze and release the rubber bulb. The
height of the float indicates the strength of he antifreeze. A thermometer and scale on the
4. How will you check the thermostat
Testing the thermostat
stamped on the thermostat, the thermostat should open. Then subonerge the thermostat
in the same solution after it has cooled to 5.5 C below the temp stamped on the
thermostat. It should close completely. If the thermostat does not open or close properly
replace it.
hard, rotted or swollen.
for exhaust gas leakage into Dc Cooling system is done by holding the exhaust

gas analyzer probe over the radiator mouth. If any leakage is there analyzer will detect it.
- check Tester. Install the tester on the radiator
filler neck. With the engine running, squeeze and release the bulb. This draws on air
sample from the cooling system through the text fluid. The test fluid is blue, if exhaust
gas is present the fluid turns yellow.
Figure:
5. Explain the pressure testing if the cooling system?
Pressure testing if the cooling system:
Fill the radiator to about 13 mm below the bottom of the filler neck. Then wipe the neck sealing
surface and attach the tester. Operate the pump to apply a pressure that doe not exceed 3 PSI
above the manufacturer’s specification. If the pressure old standy the system is not leaking. If the
pressure drops, there are leak in the system.
Make a pressure test of the radiator cap using the pressure tester. If the cap hold the pressure he
cap work properly else replace it.
belt if needed.
6. Explain the cleaning of cooling system:
Remove the thermostat and reinstall the thermostat housing and

are two types of ethylene –glycol anti freeze, high silicate and low silicate. High silicate are wed
in aluminum cylinder head engineer and low silicate are used in engines with carrion cylinder
block and header
8. Enumerate the lubricating System Troubler, and Services?
Problems:

–Pressure
A weak or broken relief valve spring
A struck pressure – relief valve
Wrong spring in the pressure relief valve
A clogged oil line
Thick oil.
Lubricating System Service
Park the vehicle on a level surface
Turn the engine ff check the oil level by withdrawing the dip stick. Also check any dirt
particle are present in the oil by rubbing the oil. If needed replace the oil.
Change the oil periodically. How often the oil, should be changed depends primarily on
how the vehicle is used. There are normally two recomendature.
Schedule – I
Changing engine oil & oil fitter every 5000 km if
Schedule – 2
Changing the oil every 12,500 km , if the vehicle is used several km daily and none of the
items in schedule 1. apply.
il change, according to the
old gasket material
Check the oil pump if badly worn, services the pump or replace it.
9. Write down the procedure for changing engine oil
Change in oil:
Raise the vehicle on a lift

Place a new maintenance sticker on the vehicle write in the odometer reading, the date,
and the type of oil used.
Oil-Filter Service:
Change the oil filter wire every oil change or every other oil change according to the operating
conditions. Most filter are unscrewed and a new filer installed by hand. You may need an oil-
filter wrench to loosen the old filter. Clean the filter mount and recess with a clean shop towel.
Make sure the old filter sealing gasket does not remain on the ( ) coat the sealing gasket on
Oil Pan service:
Whenever the oil pan is removed for ( ) or oil pump service, clean the pan, oil pick up and oil
pump. Remove all old gasket material from the gasket surfaces on the pan and block. Check
10. Write down the procedure to dinging with sketches?
All blows are made by swinging with a wrist action in a circular motion, rather than a follow

In dinging operations the dolly is placed inside of the damaged panel and held against its, surface
by pressure exerted by the foe arm.
Choose a dolly with the same slightly smaller radius than the curvature of the sheet metal being
repaired.

The general purpose dolly is placed in the damaged flange (r what is left only) and a downward
as well as outward pressure is applied on the dolly.

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