brake

1. Technician Level 2 – Module 5
Brake & Suspension System - LCV

2. Introduction
 Participant Name
 Dealership Name
 Location
 Experience in Tata Motors (In years & months)
 Specialization in which Models / Aggregates
 Hobbies
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3. Program Objectives
At the end of this module the participants will be able to:
 Understand the Construction & Components of S Cam Full Air Brake Systems in 709/909
 Identify & Describe the Function & Operation of S Cam Brake Components in 709/909
 Perform Checking, Inspection, Dismantle & Assembling of S Cam Brake Components
 Understand & Perform Checking on Exhaust Brakes
 Identify & Describe the Function, Layout of Hydraulic Brake System in Winger & 407
 Perform Adjustments, Maintenance on Hydraulic Brake System
 Overhauling the Rear Brake System - 407
 Understand & Identify the Suspension Types 7 Components of LCV
 Perform Overhauling of Front & Rear Suspension of LCV Vehicles
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4. Program Agenda
 Introduction to S Cam Brakes - LCV
– Description & Operation
– S Cam in LCV
– Layout & Types of S Cam
– Technical Specifications
 Components & Description of S Cam Brake System
 Hand Brake System S Cam Brakes
 Adjustments & Settings of Brakes S cam
 Overhauling of S Cam Brakes Front -709/909
 Introduction to Hydraulic Brakes
 Overhauling of Rear Brakes -407
 Overhauling of Park Brakes
 Introduction to Suspension System LCV
 Overhauling Suspension System - LCV
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5. S cam Service Brakes
Introduction to Brake System - LCV
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6. Classification of Brake System
 Any Brake System can basically be classified as below:
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Brake System
Foundation
Actuation
Fully Air /S Cam Brakes
Vacuum Assisted
Hydraulic Brakes
Dual Air Over Hydraulic
Brakes
Drum Brakes
Disc Brakes

7. Classification of Brake System & Application
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Brake System
Foundation
Actuation
Fully Air /S Cam
Vacuum Assisted
Hydraulic
Dual Air Over
Hydraulic
Drum
Disc
709 & above
• WABCO
• KNORR BREMSE
Ace to 407
• BOSCH
• Brakes India
Ultra Truck
• Brakes India
Rear Brakes in all models
Front Brake
• Xenon
• Ace
• 207
• Ultra

8. Brake System- Model Matrix
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Model Winger
Xenon 2.2L/
3.0L/ RX
407 /
410
709 /
909
Ultra Bus 712
/ 912 / 812
Ultra truck
912 / 812
LPT
1109
LPT
1613 TC
LPT
2518TC
Hydraulic
Front
Disc  
Drum 
Rear Drum   
Air brake
Front Drum     
Rear Drum     
DAOH
Front Disc 
Rear Drum 

9. Introduction to Fully Air/ S cam Brake System
 The “S” cam brake is the most common
type of foundation brake used on
commercial vehicles with Full air brake
systems.
 This is a drum brake that uses air brake
chambers and linkage to press the brake
shoes against the surface of the brake
drum.
 The stroke of the air brake chamber
pushrod acts on the slack adjuster
attached to the end of the camshaft.
Pushrod stroke causes the camshaft to
rotate.
 The “S” shape on one end of the camshaft
forces the brake shoes apart and against
the brake drum
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10. Description & Operation (S-Cam) - 709/909/1109
 The S-Cam brake is of sound rugged construction combining simplicity with Strength,
designed for use on Light commercial vehicles.
 The brake is operated by a ‘S’ form cam, which is an integral part of the cam shaft, the shaft
being mounted in bronze bushes in the cast torque plate. The force is applied to the shoes
through rollers seated between the shoe webs.
 A slack adjuster, which provides a quick and easy method of adjusting the brakes, to
compensate for lining wear, is fitted to the splined end of the cam shaft.
 The brake is actuated by air chamber through push rod connected to the slack adjuster.
 The brake with twin we shoes are of pressed steel construction and are pivoted on to two
hardened steel fulcrum pins which are torque plate. Two semi, circular shields cover the rear
of the brake assembly to protect the brake components from dust/road pebbles.
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11. Typical Layout of Fully Air /S Cam Brake System
1. Compressor
2. DDU with Unloader Valve
3. Front Air Tank
4. Rear Air Tank
5. Dual Treadle Valve
6. Brake Chamber - Front
7. Spring Brake Actuator - Rear
8. System Protection Valve
9. Hand Brake Valve
10. Exhaust Brake Air Cylinder
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Secondary Circuit Primary Circuit Parking Circuit

12. Different Types of S cam Brake Layouts
Vehicle: Two axle vehicle with drying & distribution unit- Layout of 709/909
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13. Different Types of S cam Brake Layouts
Vehicle: Two axle vehicle with air dryer & purge tank
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14. Different Types of S cam Brake Layouts
Vehicle: Two axle vehicle with drying & distribution unit and load sensing valve
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15. Different Types of S cam Brake Layouts
Vehicle: Two axle vehicle with air dryer & purge tank and sensing valve
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16. S cam Brakes in LCV Vehicles
 S Cam Brake System  709/909
 1109/1112
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17. Technical Specifications - 709/909
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General Specifications
Service brake
Dual circuit, S-cam full air brakes
Leading/trailing shoe drum brakes.
Parking brake Integral with spring brake actuator on rear axle graduated control.
Engine exhaust brake Pneumatically operated coupled with service brake
Drum dia. (Front & Rear) 325 mm
Lining width
Front: 118 mm
Rear: 118 mm
Lining thickness wearable lining thickness 15.6 mm tapered approx. 10 mm
Lining area
Front: 1236 cm2
Rear: 1236 cm2
Total: 2472 cm2
Brake actuators (Front: Air brake
chambers)
Type:
12 (for LP/LPT709E)
10.5/12 (SFC 709)
Stroke: 53 mm

18. Technical Specifications - 709/909
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General Specifications
Brake actuators (Rear: Spring brake
actuators)
Type:
9/9 for LP/LPT709,
10.5/12 (SFC 709)
Stroke: 53 mm
Air tank capacity Purge tank: 3.4 liters
2 nos. for all vehicles Front and rear: 15 liters each
Air compressor piston 77 mm dia. X 30 mm stroke
Air delivery at 3000 engine rpm 209 lpm (free delivery)
System pressure
Cut out: 7.4 ± 0.2 bar
Cut in: 6.2 bar min.
Low air pressure (service and
parking brake) warning signal
Operation below 5.4 ± 0.5 bar.
Parking brake hold off pressure 4.2 ± 0.4 bar.

19. Actuation System-S cam Air Brakes
Components, Description & Functions
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20. Air Compressor
 Air compressor is attached to the engine.
Air is admitted inside after air filter. The
crank shaft inside moves the piston which
compresses the incoming air. The entire
system is lubricated by engine oil.
 The reed valve between head and block
opens and close the inlet air and
compressed air. Due to any problem if the
reed valve does not operate, the pressure
gets dropped
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Video

21. Air Tanks
Air Tanks:
 To store the compressed air coming from
Air Dryer.
 There are two tanks one for front and one
for rear brakes
Draining water from air tank
 To drain the condensed water from all
the air tanks, pull the lever till the water is
drain off completely.
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22. Drying and Distribution Unit (DDU)
DDU combines function of the Air Dryer with
unloader valve, purge tank and Quadruple
System Protection valve (QSPV).
 Air Drying : Removes moisture completely
from the compressed air
 Unloading : Regulates system pressure by
exhausting the compressor delivery air to
atmosphere when system pressure reaches
maximum permissible pressure and allows
recharging of the system when the system
pressure reduces.
 Safety Valve : In case of any malfunction of
the un-loader, protects the compressor &
system by blowing off the excess pressure.
This device is integral with un-loader
mechanism.
 Quadruple System Protection Valve (QSPV) :
This function is integrated into the DDU,
which protects the healthy circuits of the
air brake system, in case of failure in one of
the circuits. The non return valves in this
position prevent back flow of stored
compressed air upstream.
 Purge Tank : This tank which is integral
with the DDU stores dry air for
regeneration of desiccant bed
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23. Drying and Distribution Unit (DDU)
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24. DDU Cycles
 During Charging, the compressor pumps air into
the service reservoirs . The water molecules in the
air get adsorbed on microscopic pores on the
surface of the desiccant beads . A portion of the
dried air is stored in the purge volume contained
in the sheet metal purge tank . During unloading
cycle at 8.1, the Unloader exhausts the
compressor delivery air to the atmosphere.
 Pressure difference between the air pressure
stored in the purge volume and below desiccant
bed, the Pressurized dry air from the purge
volume expands and flows back through a small
orifice in the purge valve over the desiccant bed.
This expansion and flow of dried air in the reverse
direction collects the moisture adsorbed by the
desiccant during the charging cycle, regenerating
the desiccant. The moisture collected by the
desiccant, condensed water, oil and other
containments are also exhausted to atmosphere in
each unloading cycle.
 Charging Cycle
 Regeneration Cycle
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25. System Protection Valve
Function
 The function of system protection valve is
to charge four lines from a common
compressor and prevent back flow of
compressed air from any line. In the event
of failure of any one of the lines, this valve
helps to maintain the other lines intact to
their operating pressure.
 The system protection valve should in
addition, also determine the order in which
the individual circuits are filled.
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26. System Protection Valve
Description
 The system protection valve consists of a
valve body, a diaphragm assembly, six spring
loaded hemispherical valves, graduating
spring and top cover. The body has one inlet
port connecting the delivery of the
compressor and four delivery ports. Two
ports are connected to two independent
reservoirs feeding air pressure to the dual
brake valve. One port is connected to the
hand brake circuit and another port is
connected to auxiliary circuits like exhaust
brake.
 The body provides valve seats for the four
elements. Each element has a spring loaded
hemispherical valve. A diaphragm assembly
locates the valves. The top cover locates the
graduating springs and secures the
diaphragm assembly through five hexagonal
head screws. A dust cover is provided t
prevent dust entry into the elements.
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Video

27. System Protection Valve
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Air pressure at Inlet below
opening pressure
Air pressure at Inlet above
opening pressure
When One air circuit fail

28. Dual Brake Valve
 It has two separate supply and delivery
circuits for service and secondary braking,
which provides the driver with a graduated
control for applying and releasing the vehicle
brakes.
 Ensures uninterrupted supply of air pressure
to secondary circuit even in case of primary
circuit failure as well as uninterrupted
supply of air pressure to primary circuit even
in case of secondary circuit failure.
 It also features an integrated mechanical
switch to activate brake indicator lights
The normal working cycles consist of
 Apply condition
 Balanced condition
 Release condition
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Video

29. Dual Brake Valve -Working
Apply Condition (Both Circuits Healthy):
 Primary circuit:
– The supply pressure always acts below the
bottom of the bonded valve and is
prevented from going to the delivery by the
inlet valve seat.
– When the pedal is pressed and the primary
piston pushes the bonded valve down
opens the inlet to delivery
 Secondary Circuit:
– Primary delivery pressure is taken as the
pilot pressure and acts on the relay piston
and pushes the relay piston.
– The relay piston pushes the bonded valve
and secondary supply goes to the delivery
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30. Dual Brake Valve -Working
Balanced Condition (Both Circuits Healthy):
 Primary circuit:
– When the pressure below the piston and
above the piston is equal, the piston moves
up.
– Bonded valve closes the exhaust and
primary piston closes the inlet.
– Constant primary delivery is maintained.
 Secondary Circuit:
– When the force below the relay piston and
above the relay piston is equal, The relay
piston moves up. Bonded valve closes the
secondary inlet and relay piston closes the
secondary exhaust
– Constant secondary delivery is maintained
 Balanced Condition:
– Inlet is closed
– Exhaust is closed
– Constant delivery is maintained
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31. Dual Brake Valve -Working
Released condition(Both Circuits Healthy):
 Primary circuit (Released condition):
– When driver removes the force acting on
the pedal,
– The air below the piston pushes the piston
and opens the exhaust valve. Air pressure
from the delivery goes to the exhaust.
 Secondary Circuit(Released condition):
– When the primary delivery gets exhausted,
the air pressure above the relay piston
decreases and the relay piston moves up
and opens the secondary exhaust
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32. Quick Release Valve
Function
 The Quick Release Valve ensures faster
exhaust of air pressure from the brake
chambers / spring brake actuators.
Description
 The Quick Release Valve is mounted close to
the brake chambers / spring brake actuators.
When brake is applied, the exhaust passage
on valve seat is closed by the diaphragm and
air pressure is admitted to the brake
chambers / spring brake actuators to which
the unit is connected. When the brake is
released, exhaust passage is opened and air
pressure from the brake chambers / spring
brake actuators is exhausted to atmosphere
through the valve instead of exhausting
through the brake valve.
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33. Relay Valve
 Function of relay valve is to release fast air
pressure from the brake chambers / spring
brake actuators Relay valve is used when
braking distance is higher from source.
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34. Brake Chamber - Front
 This is a chamber with diaphragm and return
spring. Air enters in the chamber applies the
force on diaphragm and rotate the actuators.
The spring is provided to return thr
diaphragm after release the brake.
 Brakes Applied: When the Brake Valve is
operated, air pressure enters the Brake
Chamber behind the Diaphragm and the
Push Rod rotates the Slack Adjuster, the Slack
Adjuster rotates the Cam Shaft and Cam
thereby spreading the Brake Shoes, thus
applying the brakes.
 Brakes Released: When the Brake Application
is released, Air Pressure in the Brake
Chamber is released, the Brake Chamber
release Spring and Brake Shoe return Springs
return the Brake Cam, Cam Shaft, Slack
Adjuster and Brake Chamber Push Rod to the
released position.
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Video

35. Spring Brake Actuator- Rear
 It is divided in two parts namely parking
brake having bigger spring with diaphragm.
Another part is attached to actuator acted
by another diaphragm. Both are
interconnected.
 This assembly is a combination of
diaphragm brake chamber and spring
actuator with mechanical rear wind off
arrangement. While the diaphragm is for
actuating service brakes and spring loaded
piston is for secondary / parking brake
actuation, the mechanical wind off
arrangement is for releasing the spring
brake in case of emergency viz. to release
spring brakes temporarily should occasion
arise where the vehicle has to be moved
after a failure in the brake system.
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Video

36. Spring Brake Actuator- Rear
Operation of Spring Brake Actuator:
There are three condition sin which the Operation can be explained:
 Condition-1: Normal Vehicle Running
 Condition-2: Service Brake Application & Release
 Condition-3: Parking Brake/Safety Brake Application & Release
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37. Spring Brake Actuator- Rear
Condition-1: Normal vehicle running condition:
 Service side
– Service brake push is kept in its rest
position by means of a return spring and
the brakes are in the released condition.
 Spring side
– The graduate hand control valve should be
kept in Brakes ‘OFF’ position. Supply air
acts via port 12 on the ram in the spring
chamber and compresses the heavy coil
spring and brakes are in the released
position.
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38. Spring Brake Actuator- Rear
Condition-2: Service brake application & release:
 When the brake pedal is pressed, compressed air is applied via port
11 to the pressure side of the diaphragm which actuates the push
plate sub assembly that displace against the force of the return
spring, and braking force is generated.
 The amount of force exerted is dependent on the supply air pressure
from the dual brake valve and on the effective diaphragm area,
which is deflection / stroke dependent.
 On release of the service brakes, air returns through port 11 and
exhausts through the dual brake valve, thereby the return spring
causes the push plate sub assembly and diaphragm to move back to
rest position and brakes are released.
 The breather holes are provided in the Non-pressure plate to
maintain pressure equalization with the atmosphere so that no
dynamic counter pressure / vacuum can be built up when the
service brake is actuated / released.
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39. Spring Brake Actuator- Rear
Condition-3: Parking brake/ Safety brake
application & release:
 When the parking brakes are applied
(Graduated hand control valve kept in brakes
‘ON’ position), air from spring side is
exhausted through port 12, causing the
expansion of compressed heavy coil spring
and also the ram moves towards the fork
end. This in turn displace the diaphragm,
which causes the service brakes push plate
sub-assembly to displace against the force of
the return spring and braking force is
generated. The amount of force exerted is
proportional to the reduction in air pressure
at port 12.
 In order to maintain pressure equalization at
the spring of the spring chamber, during
actuation / release of spring brake, the spring
side of the spring chamber is connected to
atmosphere through an external breather
tube connected to the non pressure plate.
Manual wind off feature:
 In the event of loss of air pressure in the
brake system, the spring brakes will be in the
applied condition. In order to release the
spring brakes, a wind off rod is provided
which can be used for manually releasing the
spring brakes.
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40. Spring Brake Actuator – Applied Conditions
 Emergency/Hand Brake Applied Position  Spring Brake Mechanically Wound Off
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41. Spring Brake Actuator – Don'ts
For parking & emergency braking:
 Ensure the spring brake chambers in wind in condition
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Spring Brake Chamber Wind off condition Spring Brake Chamber Wind in condition

42. Park Brakes: Graduated Hand Control Valve
Function
 The purpose of this valve is to gradually
charge and exhaust air from spring brake
chamber for releasing / applying the parking
or emergency brakes in a truck or a tractor.
Description
 The valve mainly comprises of an inlet
exhaust valve, a cam, a cam follower. These
are housed in a valve body and a top cover.
The cam is actuated by a lever with a knob.
The position of the lever is locked by means
of a sleeve which gets located in a
corresponding slot in the top cover. The top
cover is provided with a gaiter to prevent
dust entry into the valve. A dial is provided to
the valve to indicate the ‘ON’ & ‘OFF’
positions of brakes.
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Video

43. Park Brakes: Graduated Hand Control Valve
Off Position:
 Parking brake is operated by air supply
from system control valve and it sends air
continuously to the rear brake actuator.
This position is called as ‘Parking brake
OFF’ .
On Position:
When brake is applied, the supply stops and
air gets cut from actuator spring chamber. This
position is called as ‘Parking brake ON’.
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44.  Air Compressor Cylinder Head Assembly
 Air Drier Assembly
 Automatic Load Sensing Valve
 Brake Chamber, Front, Type -10.5 & Type 12
 Drying and Distribution Unit (DDU)
 Dual Brake Valve
 Graduated Hand Control Valve
 Spring Brake Actuator, Rear, Type
 System Protection Valve
Remove & Refit, Inspection, Checking of S Cam
Components – 709/909
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Remove & Refit,
Inspection, Checking of S
Cam Components-
709/909

45. Foundation Brakes-S cam Air Brakes
Components, Description & Functions
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46. Layout of S cam Foundation Drum Brakes
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47. Introduction to Foundation Brake System - LCV
Types of Foundation Brake System – Drum Brakes
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Duo-servo brake Hydraulic brakes DAOH (Dual Air Over
Hydraulic) brakes
Pneumatic brakes
When a primary side leading
shoe is pressed against the
drum by the wheel cylinder,
the force that makes it rotate
together with the drum
wedges the secondary side
leading shoe into the drum to
achieve braking action.
Xenon / Winger. leading
shoe is pressed against the
drum by the wheel cylinder.
It is H2LS type on auto
adjusting system. It is not to
sensitive to liner gap
adjustment, liner
adjustment is done by
wheel cylinder adjuster
mechanism.
S shaped cam (S-cam in
short) for brake shoe
movement

48. Introduction to Foundation Brake System - LCV
Leading and Trailing Shoe
 Leading (or primary) shoe is moving in the
direction of rotation of S cam when it's
being pressed against the drum.
Leading and Leading Shoe
 Leading brake shoes are pressed against
the drum in the direction of rotation.
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Leading
Trailing

49. Exploded View of Rear Drum Brakes - General
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50. Exploded View of S-Cam Brake (Front) - 709/909
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51. S-Cam Brake Shoe (Front) - 709/909
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M16 (2 Nos.) M12 (4 Nos.)
Sr. No. Description
1 Leading brake shoe assembly
2 Trailing brake shoe assembly
3 Brake support
4 Top return spring
5 Bottom return spring
6 Cam shaft
7 Brake chamber MTG bracket
8 Dust cover

52. Exploded View of S-Cam Brake (Rear) - 709/909
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53. S-Cam Brake (Rear) - 709/909
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Sr. No. Description
1 Leading brake shoe assembly
2 Trailing brake shoe assembly
3 Brake support
4 Top return spring
5 Bottom return spring
6 Cam shaft
7 Dust cover

54. Slack Adjuster- 709/909
Introduction
 The function of slack adjuster is to provide a
quick, easy method of adjusting brakes to
compensate for brake lining wear.
Description
 The Slack Adjuster consists of a forged steel
body, a worm gear operated by a worm
through a worm shaft. The worm shaft is
prevented from unintentional rotation by a
worm shaft lock.
Operation
 Slack Adjusters perform a two-fold function:
1. They serve as a lever during normal braking
operation.
2. They provide a quick and easy method of
adjusting brakes.
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55. ASA Installation Process – Haldex
S-ABA Exploded view
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Sr. No. Description Sr. No. Description
1 Housing 28 O-Ring
2 Bushing 40 Rivet
3 Worm Wheel 46 Plastic Insert
4 Worm Shaft 47 Compression Spring
5 O-ring 48 Spring Support
10 Needle Bearing 49 Adjusting Screw
11 Front cover 50 Toothed Plate
12 Control Unit Assembly 51 Companion Flange
12a Control Arm 52 Gear Wheel Spring
17 Coil Spring 53 Gear Wheel
18 Thrust Washer 54 Regulator Shaft
20 Rear Cover 55 Control Disc
24 Torx Screw 56 Clutch Wheel
27 Gasket

56. ASA Installation Process – Haldex
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Block wheels to prevent vehicle from
rolling
Check the push rod is fully retracted
Apply (min 6 kg/cm2) air to release
spring brake.
Clean ‘s’ cam shaft splines.
Apply Grease an ‘s’ cam shaft splines. Check there is no excessive play or
wear in camshaft / bushes
(recommended maximum play 0.5
mm) clevis pin/ bushes and control
arm anchorage attachments.
Space washers with dia. 60 mm or more
should be installed ‘s’ cam shaft.

57. ASA Installation Process – Haldex
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Install Anchor Bracket loosely at
suitable area (Don’t tighten anchor
bracket)
Install the brake adjuster on the ‘s’
cam shaft with the adjuster Hexagon
pointing away from the Brake chamber
Rotate the Adjuster Hexagon worm
shaft clockwise until the brake Chamber
clevis hole line up with adjuster arm
hole
Install the Clevis Pin Space washers with dia. 60 mm or
more should be installed against
control lever
Add Shims/Spacer according to
maintain (0.5-2 mm) Axial Play & Lock
S-ABA with Circlip

58. ASA Installation Process – Haldex
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Move the Control Arm to align with
Anchor Bracket Slot & Tighten all the
Anchor Bracket Fasteners.
Rotate the Adjuster Hexagon worm
shaft clockwise until Brake Linings
Contact the Brake Drum.
Rotate the adjuster Worm Shaft
Anticlockwise 270 degrees or ¾ of a
turn. A Minimum of 18 NM Torque is
required to overcome the internal
Clutch, A Ratcheting Sound will occur.

59. ASA Installation Process – Haldex
Do’s
 Always do the Installation in spring brake
release condition only. (Apply min 6kg/cm.
sq Air to release.
 Always check for no excessive play or wear
in cam shaft (Recommended maximum
play 0.5 mm)
 Always Install space washer with diameter
60 mm against control lever.
 Always tighten all anchor bracket fasteners.
 Always rotate the adjuster Hexagon worm
Shaft anticlockwise more than 270 deg or
¾ of a turn.
Don’ts
 Never do the installation in spring brake
applied condition.
 Never keep any of the fasteners loose.
 Never rotate the adjusters Hexagon worm
shaft less than 270 deg. Or ¾ of turn.
 Never use high torque gun to adjust the
brakes.
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60. ASA Installation Process – MEI
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1 2 3 4
Block the wheels from rolling.
Ensure Air pressure is above 7.0
Ksc.
Check the push rod is in fully
released position.
Install anchor bracket loosely.
DO NOT TIGHTEN ANCHOR
BRACKET.
All grease on camshaft splines.
Fit then SASA on to the
camshaft with the 12 mm
adjusting HEX in the opposite
side of brake chamber. Use at
least one inner washer & outer
washer as necessary & secure
the circlip. Ensure end play of
slack adjuster on cam shaft is
more than 0.5mm. Rotate 12
mm adjusting HEX clockwise &
align clevis hole. Do not pull the
slack adjuster or the clevis to
align the holes. Fix the clevis
pinbolt &secure.
Rotate control arm until the
screw aligns with Anchor
bracket slot. Tighten all anchor
bracket fasteners.
Rotate the 12 mm adjusting HEX
clockwise until lining contacts
drum.
Back off 1800, by turning the 12
mm adjusting HEX counter
clockwise.
Minimum 18 Nm is necessary to
over come internal clutch
resistance.
Ratcheting sound will be heard.

61. Automatic Load Sensing Valve
Function
 The Automatic Load Sensing Valve (ALSV)
has been designed to regulate the braking
force on a particular axle in proportion to
the load on that axle, and is controlled by
the variations in the spring deflection of
mechanical suspension systems. In ALSV,
the regulation of delivery pressure takes
place automatically in response to the
change in the load on the axles of the
vehicle.
7/28/2022 TML 61

62. Automatic Load Sensing Valve
Operation
 The ALSV is mounted on the vehicle chassis and the operating lever is connected to the axle
through a simple linkage. When the vehicle is empty, the distance between the axle and the
ALSV is greatest and the lever end is in its lower most position. As the vehicle is loaded, the
distance between axle and chassis decreases, and the lever end moves upwards causing the
cam to rotate which in turn moves the tappet to a position corresponding to the vehicle load.
 When a brake application is made, air at brake line pressure is fed through inlet port into the
upper chamber forcing the moving fin with piston downwards, which closes delivery from
exhaust and connects inlet to delivery. The air now flows into the chamber below diaphragm
and flows out through delivery ports to brake actuators. At the same time, air flows into
chamber above diaphragm through the opened in-shot valve and acts on the upper side of
the diaphragm. Thus pressures above and below the diaphragm are equalized. This pressure
control provides un-modulated output at low inlet pressure. If the inlet pressure increases
further, the in-shot piston is pressed further against the in-shot spring load and in-shot valve
closes. There will not be any further increases in pressure above the diaphragm.
7/28/2022 TML 62

63. Automatic Load Sensing Valve
Operation..
 As the moving fin with piston moves down, the diaphragm begins to move away from the
stationary fin, pushed away by the fanned out portion of the moving fin. This alters the
effective area of the diaphragm supported by the moving fin with piston, until the force under
the diaphragm, which depends on the pressure and the effective area, equals that acting on
the top of the moving fin piston and the inlet valve closes. Balance is therefore achieved with
a lower delivery pressure than that applied at the inlet port, keeping the valve assembly in
the “lapped” condition with the inlet and exhaust closed. The applied pressure is thus
regulated in proportion to vehicle spring deflection.
 As the effective area of the diaphragm depends on the position of the moving fin attached to
the piston, which in turn depends on the position of cam attached to lever, the output
pressure to the brake actuators will be increased or decreased according to the load on the
axle.
7/28/2022 TML 63

64. Automatic Load Sensing Valve
Operation..
 When the brake is released, the pressure in the ALSV supply line (between the Dual Brake
Valve and ALSV) falls and will result in loss of balance of air forces on the moving fin piston.
This results in unseating of the valve from the tappet, allowing air below the diaphragm to
exhaust to atmosphere through the hollow tappet and out of the exhaust. A silencer is
provided to reduce the noise due to exhaust.
7/28/2022 TML 64

65. Automatic Load Sensing Valve- Adjustment
 In Unladen vehicle condition With and
without load body (Ensure after load body
LCRV to be readjusted) loosen screw after
B rotate link A by sliding rubber connector
over link C Such that point P on Dial D
Coincides with point Q
 Tighten the screw B
 Ensure link C is properly attach & lock with
lock pin on rear axle bracket
Note:
 Gap setting: Notch to be matched with rib
7/28/2022 TML 65
Sr No. Model VC Holes Fitted
1 LPK 909/27 28214527000R 1 D
2 LPT 709/38 26420938000R 1 D
3 LPT 1109/36 21902936000R 1 D
C
B
A
Q
P
D
P
Q

66. Electrical Indicators & Gauges - 709/909
In S-Cam full air brakes, following indicators gauges are provided for warning about any failure in
the system.
 Low air pressure indicator (Red)
– Two low pressure (LP) switches are connected separately for front and rear air circuits at dual brake
valve.
– Both switches are connected to one (low air pressure) indicator on instrument panel.
– When pressure is below specified value indication comes on panel.
 Hand brake indicator (Red) and beeper
– One LP switch is connected at graduated hand brake valve outlet.
– This is connected to (hand brake) in indicator on panel.
– When pressure is below specified value or whenever hand brake is applied, (Hand Brake) indication
on panel and audio beeper signals come together.
7/28/2022 TML 66

67. Electrical Indicators & Gauges - 709/909
 Mechanical stop light switch
– A mechanical stop light switch is mounted below brake control lever mounting box.
– Whenever brake pedal is depressed for applying brakes, stop light switch comes into operation and
lights at rear tail lamps glow.
– This also providers signal to exhaust brake solenoid valve.
 Two air pressure gauges
– Two air pressure gauges are provided separately for front and rear air brake circuits.
– Air connections are taken from dual brake valve.
7/28/2022 TML 67

68. Electrical Indicators & Gauges - 709/909
 Engine Exhaust Brake Indicator
– Exhaust brake operation is coupled with service brake.
– Whenever brake pedal is depressed for applying brakes, exhaust brake also gets applied and
indicator lamp (E) glows on the instrument panel.
– Stop light switch provides signals both for rear tail lamps as well as for exhaust brake solenoid
valve.
– Solenoid valve opens, allowing the compressed air to flow to air cylinder thus, operating the
exhaust brake, if isolator switch is kept ‘ON’.
 Isolator Switch (Exhaust Brake)
– In certain situations like starting of vehicle on an up-gradient, simultaneous acceleration and partial
braking of vehicle are required, Isolator switch can be used to cut off air supply to exhaust brake, by
putting in off (disengaged) position.
– Isolator switch should be put on (engaged), as soon as isolation requirement is over.
7/28/2022 TML 68

69. Lubrication & Maintenance of Air Brakes
7/28/2022 TML 69
Sr. No. Operation Frequency in kms
1 Drain off condensed water from air tanks 9,000
2
Dismantle pneumatic aggregates of brake system clean, inspect & replace parts if
necessary. Apply grease to components while re asly 72,000
3
Check performance of brake by applying / releasing the brakes. Check and if necessary
adjust parking brake. 5,000
4 Check the vacuum booster gaiter for proper fitment and damage replace if necessary. 20,000
5 Check front and rear brake lining replace if necessary. 20,000
6 Change filters and gaiter of vacuum booster. 40,000
7 Change brake fluid in the brake system and bleed the system. 40,000
8
Overhaul the vacuum booster assembly using recommended repair kit (consisting of
non-return valve rubber grommet, sealing ring, operating rod assembly. Filters, lip seal
and gaiter) and diaphragm. Replace pivot plate assembly, if necessary 80,000
9
Dismantle, clean, inspect and re-assemble tandem master cylinder, wheel cylinder of
brake system. 80,000

70.  Removal of Shoes
 Re-Lining the Shoes
 Fitment of Shoes
 Servicing of Camshaft
 Removal of Camshaft
 Examination of the Parts
 Removal of Rear Brake
 Installation of Rear Brake
 Fitment Instructions
Major O/H of Front & Rear Brakes - 709/909
7/28/2022 TML 70
Major O/H of Front &
Rear Brakes - 709/909

71. Adjustments of Brakes & Controls
S Cam Air Brakes Adjustments
7/28/2022 TML 71

72. Adjustment of Brake Controls
Adjustment of Brake Pedal Free Play
 A certain amount of play is kept between
dual brake valve spindle and double lever pin.
This is to ensure that accidentally brakes do
not get operated. There will be slight hard
feeling at brake pedal while depressing, when
play is zero. The travel of brake pedal till play
is zero, can be defined as “brake pedal free
play”.
 Adjust brake pedal free play as below:
– Ensure brakes are in released condition.
– Loosen check nuts on the pedal stopper
screw near stop light switch. Adjust stopper
screw such that brake pedal free travel is 3 to
6 mm.
– Tighten check nut of stopper bolt without
disturbing.
– Operate brake pedal a few times to ensure
desired brake pedal free play.
7/28/2022 TML 72

73. Adjustment of Brake Controls
Adjustment of stop light switch
 Ensure that brakes are in released
condition.
 Adjust dimension 3 mm between stop light
switch and double lever as shown in
drawing. Tighten lock nuts.
 Operate brakes a few times, to make sure
that stop light indication comes properly.
7/28/2022 TML 73

74. Engine Exhaust Brake System
Engine Exhaust Brake System
7/28/2022 TML 74

75. Engine Exhaust Brake System
Advantages
 A step towards greater economy and better control. Engine exhaust brake is an auxiliary brake
supplementing the main service brake.
 Use of engine exhaust brake will result in increased life of brake liners/drums.
Operation
 Every time you apply brake, the engine exhaust brake comes into play. When the brake pedal
is depressed, the double lever operating the truck brake valve of the service brake
simultaneously the stop light switch gives signal to electric solenoid valve to open, letting
compressed air into the exhaust brake cylinder. This operates the butterfly valve in the
exhaust system and applies the exhaust brake.
 During this operation, since the accelerator pedal is in idling position and the exhaust opening
is restricted, the road wheels will drive the engine, which will act as a compressor (resistor),
thus retarding the vehicle speed, without in any way being detrimental to the engine vehicle.
7/28/2022 TML 75

76. Engine Exhaust Brake System
Operation..
 The use of engine exhaust brake results in
increased life of service brake linings and drums.
 When the brake pedal is released, then stop light
signal goes ‘OFF’ and solenoid valve closes,
thereby cutting off the air supply. The exhaust
brake cylinder become open to atmosphere
facilitating its spindle to return home.
Operating Instructions
 Ensure air pressure in the tank is above 6 bar.
 Change to lower gear which is appropriate to road
conditions. The engine exhaust brake is very
effective below the vehicle speed of 40 kmph.
 Do not depress the clutch as this would render the
exhaust brake ineffective.
 Press brake pedal fully when the vehicle is to be
brought to a stop. For parking, the vehicle, engage
hand brake and low gear.
7/28/2022 TML 76

77. Engine Exhaust Brake System
Lubricating the exhaust brake linkages
 The exhaust brake requires a minimum of service. Every 5,000 km a few drops of oil should be
applied to the ball pins of outer linkages and friction surfaces.
 The butterfly valve shaft, which is made of heat resistant material, should not be lubricated
since the lube oil would cause seizing of the butterfly valve in the exhaust manifold.
 Remove, clean and refit exhaust manifold butterfly valve and shaft (Do not lubricate) once in
80,000 km.
7/28/2022 TML 77

78. Engine Exhaust Brake System
Exhaust Brake Valve Adjustment
 There is no separate exhaust brake valve adjustment. Stop light switch serves the function of
providing signals both for rear tail brake lamps as well as for exhaust brake solenoid valve.
 Check proper functioning of engine exhaust brake at PDI and every 10,000 km with brake
pedal fully released, there should be no exhaust brake application. If it is on, re-adjust stop
light switch suitably. Exhaust brake application can be made out from distinct change in
engine noise.
7/28/2022 TML 78

79. Exhaust Brake Actuator Function
 When the air cylinder is actuated, the
linear motion of the output rod of the air
cylinder is converted into a rotary motion,
by means of a lever mechanism.
 Thereby the baffle plate connected to the
lever is made to rotate, which partially
closes the engine exhaust gas passage
creating the required back pressure in the
engine.
 Two stoppers are provided to control the
baffle plate opening.
7/28/2022 TML 79

80. Tata -407/207/Xenon & Winger
Vacuum Assisted Hydraulic Brakes System
7/28/2022 TML 80

81. Introduction to Hydraulic Brakes System
The Hydraulic Braking Systems are used in below Models of LCV range of Vehicles:
 Tata 207 Family
 Tata Winger
 Tata 407 Family
 Tata 409/410 Family
 The Service Braking System in these vehicles is Hydraulically Operated on all front and rear
wheels with dual line system to provide separate hydraulic circuits for front & rear brakes
 The Hydraulic System is split between the front & rear brakes
 To reduce the pedal effort, a vacuum booster is fitted between the Brake Pedal and Tandem
Master Cylinder.
 The vacuum required for the assistance will be provided by the Vacuum Pump.
 If the Servo unit fails, Brakes still operates Mechanically.
7/28/2022 TML 81

82. Models of Vehicle in Which The System is Used
7/28/2022 TML 82
Service Brake: Vacuum assisted, hydraulic dual
circuit brake with tandem master cylinder.
Front & rear: Drum brake
Parking brake: Cable operated, Mechanical brake on
rear wheels.
Service Brake: Vacuum Assisted Independent
Hydraulic Brakes on Front & Rear with Tandem
Master Cylinder.
Front & rear: Front Disc brake & Rear Drum brake
Parking brake: Floor Mounted cable Operated
Mechanical Linking acting on rear wheel.

83. Brake System Layout - 407
7/28/2022 TML 83
Engine stop cylinder Exhaust brake cylinder
Solenoid switch for
exhaust brake cylinder
Solenoid switch for
engine stop cylinder
Vacuum pump
Wheel cylinder rear
Wheel cylinder front
LCRV (if fitted)

84. Technical Specifications - 407
7/28/2022 TML 84
Service Brake Vacuum assisted, hydraulic dual circuit brake with tandem master cylinder.
Front & rear Drum brake
Parking brake Cable operated, Mechanical brake on rear wheels.
Braking area
Front
Rear
Total
990 cm2
990 cm2
1980 cm2
Tandem Master Cylinder dia 25.40 mm
Tandem Master Cylinder stroke
Front
Rear
18 mm
15 mm
Wheel cylinder diameter
Front
Rear
23.81 mm
22.22 mm
Vacuum booster dia
Stroke
228.6 mm
36 mm
Working pressure 0.2 bar absolute

85. Technical Specifications - 407
7/28/2022 TML 85
Vehicle
Tandem Master Cylinder Wheel Cylinder Dia. Vacuum Booster
Dia.
(mm)
Stroke
Front / Rear (mm)
Front / Rear (mm) Dia. (mm)
Stroke
(mm)
For BS II SFC 407 ST / TT
SFC 407 - 4X4
LP 407 TT
23.81 18 / 15 22.22 / 17.78 254 36
For BS II SFC 407 ST Bus 23.81 18 / 15 22.22 / 19.05 254 36
For BS II LP 407 ST 23.81 18 / 15 25.4 / 22.22 254 36
For BS III SFC / LP / LPT 410 25.4 16.1 / 14.9 23.81 / 22.22
228.6 + 203.3
(Tandem booster)
31
For BS II LPT 407 EX 25.4 16.1 / 14.9 23.81 / 22.22
228.6 + 203.3
(Tandem booster)
31
For BS II LPT 407 TT 25.4 16.1 / 14.9 23.81 / 22.22
228.6 + 203.3
(Tandem booster)
31
(ST = Single Tyre Rear Wheel, TT = Twin Tyre Rear Wheel)

86. Lubrication & Maintenance - 407
7/28/2022 TML 86
Sr. No. Operation Frequency in kms
1
Check performance of brake by applying / releasing the brakes. Check and if necessary
adjust parking brake.
5,000
2 Check the vacuum booster gaiter for proper fitment and damage replace if necessary. 20,000
3 Check front and rear brake lining replace if necessary. 20,000
4 Change filters and gaiter of vacuum booster. 40,000
5 Change brake fluid in the brake system and bleed the system. 40,000
6
Overhaul the vacuum booster assembly using recommended repair kit (consisting of
non-return valve rubber grommet, sealing ring, operating rod assembly. Filters, lip seal
and gaiter) and diaphragm. Replace pivot plate assembly, if necessary
80,000
7
Dismantle, clean, inspect and re-assemble tandem master cylinder, wheel cylinder of
brake system.
80,000

87. Components of Hydraulic Brake System
Vacuum Booster:
 Vacuum Booster provide power assistance by boosting up the mechanical effort on the
attached hydraulic Master cylinder using the pressure difference between atmosphere and
vacuum.
Single Diaphragm Double Diaphragm
7/28/2022 TML 87

88. Trouble shooting of vacuum booster assembly
7/28/2022 TML 88
Basic Test
OFF the engine, press brake pedal several times to remove vacuum from Booster Assembly. After this the
pedal application will feel hard to press.
Press the brake pedal and hold with light pressure of @ 10kg. Start the Engine.
If the booster is functioning satisfactory, the pedal will fall slightly and then hold.
If the booster is not operating
Disconnect the vacuum hose from the NRV.
Then with Engine Running, check vacuum supply with a vacuum gauge.
There should be at least 700 mm of Hg* vacuum for Diesel and 550 mm of Hq* for
petrol vehicle.
If the booster is operating
Please turn over and do
Vacuum Leak Test.
If, Vacuum supply is below 700 mm of Hg* for Diesel and
550 mm of Hg* for Petrol vehicle, replace or repair
vacuum hose and vacuum source.
If, Vacuum supply is 700 mm of Hg for or more for Diesel
or 550 mm of Hg or more for Petrol vehicle, then the
booster is faulty and should be replaced.
When adequate vacuum supply is obtained, repeat basic
test.

89. Vacuum Booster Checking
7/28/2022 TML 89
Vacuum Leak Test
Run engine to medium speed. Release accelerator and turn Engine OFF. This builds up the vacuum.
Wait for 90 seconds and then apply brakes. Two or more applications should be vacuum assisted.
If Applications are not Vacuum Assisted
Disconnect vacuum hose from vacuum source or NRV
whichever is easier.
If disconnected from NRV , attach short length of hose to
valve.
Blow into hose attached to NRV. If air passes through,
valve is defective.
If Applications are Vacuum Assisted
There is no vacuum leak.
Perform the Hydraulic Leak Test.
If NRV or Check Valves is OK
Vacuum booster is leaking and should be replaced.
If NRV or Check Valves is Defective
Install new NRV (KBX 422) and repeat Vacuum Leak Test.

90. Components of Hydraulic Brake System
Master Cylinder:
 To develop hydraulic pressure and control the service braking process.
7/28/2022 TML 90

91. Components of Hydraulic Brake System
Wheel Cylinder:
 To transmit the force developed by hydraulic oil pressure to the brake shoes.
7/28/2022 TML 91

92. Components of Hydraulic Brake System
 Front Brake Assembly:
7/28/2022 TML 92
1 Primary Brake Shoe Assembly
2 Wheel Cylinder
3 Brake Support
4 Spring (Shoe Return Upper)
5 Secondary Brake Shoe assembly
6 Anchor Plate
7 Inspection Window
8 Axial Retaining Pin Assembly
9 Spring (Shoe Return Lower)
10 Brake Adjuster
8 5
2
3
6
7
9
10
1
4

93. Components of Hydraulic Brake System
 Rear Brake Assembly
7/28/2022 TML 93
Wheel Cylinder
Primary Brake
Shoe Assembly
Brake Support
Rotation of brake in
Forward direction
Secondary Brake
Shoe Assembly
Spring (Shoe
Return Upper)
Anchor Plate
Axial Retaining
Pin Assembly
Spring (Shoe
Return lower)
Brake Adjuster

94. Hydraulic Brake System Layout – 207/ Xenon &
Winger
7/28/2022 TML 94
LCRV

95. Technical Specifications - Winger
7/28/2022 TML 95
Specifications
Service Brake
Vacuum Assisted Independent Hydraulic Brakes on Front & Rear with
Tandem Master Cylinder.
Front Brake 252 Dia. Ventilated Disc Brake
Rear Brake 252 Dia. Drum Brake lite LSPV
Parking Brake Floor Mounted cable Operated Mechanical Linking acting on rear wheel.
Tandem Master Cylinder Assembly
Type Compensatory Port Type
Diameter 26.99 mm
Primary Stroke 19.00 mm
Secondary Stroke 11.75 mm
Primary Connected to FRT. RH and LH Leading Caliper Pistons and Rear brakes
Secondary Connected to FRT. RH and LH Trailing Caliper Pistons

96. Technical Specifications - Winger
7/28/2022 TML 96
Specifications..
Tandem Booster Assembly
Type Tandem (Twin Diaphragm) Type Vacuum Booster
Size 8” + 9”
Boost Ratio 8 + 9.5
Front Disc Brake
Specifications Twin Pot Caliper
Bore Dia. 2 X 45 mm
Friction pad Grade R 804 (Asbestos Free)
Type Double Piston Floating Caliper
Rear Brake System
Type & Dia. RAUI, 255 X 58 mm
Wheel Cylinder 22.22 mm
Lining AF 2046 M

97. Technical Specifications - Winger
7/28/2022 TML 97
Specifications..
Load Sensing Type Proportioning Valve
Type Load Sensing Type Proportioning valve with integral bypass valve.
Knee Point (Un-laden) 32 Bar
Slope 0.3
Inlet of LSPV From TMC Primary Section delivery port
Outlet port of LSPV To Rear Brakes

98. Lubrication & Maintenance - Winger
Service Limits
 Frictional Material
– Do not allow the friction material on pad to wear till the groove; in the same way, do not allow the
friction material on brakes shoe to wear till 1.5 mm of frictional material remains.
 Tandem Master Cylinder
– If, the clearance between the piston and cylinder bore exceeds 0.20 mm, TMC assembly should be
replaced.
 Wheel Cylinder
– If, the clearance between the wheel cylinder piston and cylinder bore exceeds 0.25 mm, Wheel
cylinder assembly should be replaced.
 Seals
– All RUBBER Parts including Seals, should be replaced as specified in the service schedule.
7/28/2022 TML 98

99. Front Disc Brake Assembly - 207/ Xenon & Winger
7/28/2022 TML 99
Guide Pin
Lock Pin
Bleeder Screw
Piston
Piston
Pad Sub assembly
Pad

100. Bleeding of Hydraulic Brake System
Procedure :
 Place the Ring spanner on Bleed Screw as
per the Sequence.
 Fit the Bleeder pipe one end on Bleed
Screw and other end in the bleeder bottle.
 Press the Brake Pedal 3 ~ 4 times (Time
interval should be 4 ~ 5 seconds in
between applications)
 Hold the Brake pedal pressed condition,
loose the bleed screw 2~3 turns to allow
brake fluid & air drain /remove from the
system and tighten the bleed screw
immediately.
 Repeat the procedure till such time air
presence in the system.
 Repeat the same in other wheels.
7/28/2022 TML 100

101. Bleeding of Hydraulic Brake System
Note :
 During bleeding don’t allow the fluid level
in fluid reservoir below the minimum level.
 Don’t use the drain brake fluid to top the
fluid reservoir. This may cause spongy
pedal feel as the fluid mixed with air.
 Ensure proper tighten torque of bleed
screw after completion of bleeding.
 Clean the bleed screw after completion of
bleeding with clean dry cloth to ensure any
leakage
 Bleeding Sequence
7/28/2022 TML 101

102. Brake Adjustment Procedure
 Lift the axle with jack to make wheel free.
 Loose the brake adjuster mounting M12 bolt
 Lock the brake drum to centralize auto adjuster.
 Tighten Adjuster mounting bolt with 9.5 kgm torque
 Set brake liner & ensure brake drum is free. if require measure liner gap not more than 0.5
mm by filler gauge
 Ensure both adjuster screw are free.& 2.8 -3 mm gap between Paul plate end & primary
ratchet wheel.
7/28/2022 TML 102

103. Brake Adjustment Procedure
7/28/2022 TML 103
Brake Adjuster
Mounting M12 Bolt
1. Arrow mark with “P” on pawl should face the primary
brake shoe (front of vehicle)
2. Gap between primary ratchet and pawl to be maintained
at 2.8 to 3 mm
Tool pushing the pawl to
release the ratchet wheel
1
2

104. Brake Setting – Auto Adjuster
1. Fit the sleeves on to the adjuster with the
threads of the screws fully inside
2. Make sure that the removed shims are
intact with the sleeves.
3. Rotate one of the ratchet wheel in the
adjustment direction and make sure that
both the wheel are rotating
4. Fit the adjuster on the brake assembly
tighten the adjuster mounting bolt so that
it grips the adjuster tightly.
5. Check the gap between the primary side
ratchet wheel and pawl gap is between
2.8 and 3mm.If not suitable add or
remove shims to adjust to this gap
7/28/2022 TML 104

105. Brake Setting – Auto Adjuster
Adjustment of brake liner with brake adjuster
 Check Pawl movement
 Special tool to lift pawl
7/28/2022 TML 105

106. Pedal Height Adjustment
 Brake pedal height for LP / LPT 220 mm &
for SFC 195 mm inline with Clutch pedal
height from bracket top mounting bolt.
 Loosen brake light switch, loosen nut on
adjusting eccentric pin of level.
 Turn the eccentric pin to get the required
pedal height & tighten the nut. Install the
brake light switch.
 Switch Adjustments: Adjust the position of
stop light switch so that the switch plunger
is depressed by 3mm.
7/28/2022 TML 106
Eccentric Pin

107. Park Brake System Overhauling - 407
Park Brake System Overhauling
7/28/2022 TML 107

108. Parking Brake System
7/28/2022 TML 108
Knob
Handle Assy. Link
Assy Cable Front
Lock nut
Adjusting nut
Assy. Cable rear

109. Parking Brake System (LP /LPT)
7/28/2022 TML 109
Assembly parking
brake unit
Parking brake handle
Assy. Link
Assy Cable Front
Lock nut
Adjusting nut
Assy. Cable rear
View - Y

110. Park Brake Adjustment – 407/410
 Jack up the rear axle so wheels can rotate
freely.
 Release parking brake fully.
 Slacken parking brake linkage by
unscrewing lock nut & adjusting nut.
 Pull parking brake lever to 6nd click on
ratchet rod.
 Tighten adjusting nut, till rear brakes fully
jam.
 Release parking brake & ensure free
rotation of rear wheel.
Please note hand brake cable for LP,SFC 31 is
different than LP 34 WB
7/28/2022 TML 110

111. Park Brake Adjustment - For SFC Model
 Adjust Parking brake after adjusting rear
brake.
 Release parking brake lever to extreme
bottom.
 Slacken parking brake adjustment by
unscrewing the adjusting nut and lock nut.
 Pull up lever by six “clicks” on toothed
ratchet.
 Tighten adjusting nut till rear brakes are
fully jammed.
 Release parking brake & ensure free
rotation of rear wheels.
 Tighten lock nut against the adjusting nut.
 Recheck parking brake application.
7/28/2022 TML 111

112. Park Brake Adjustment-For LP / LPT Model
 Adjust Parking brake after adjusting rear
brake.
 Jack up rear axle.
 Release parking brake fully.
 Slacken parking brake linkages by unscrewing
lock nut and the adjusting nut. Rotate
adjusting nut till it is hand tight.
 Pull the parking brake handle to 6 click on
ratchet rod.
 Tighten adjusting nut, till rear brakes are fully
jam.
 Release parking brake & ensure free rotation
of rear wheels.
 Tighten lock nut against the adjusting nut.
 Operate parking brake a few times to ensure
its proper operation.
 Lower down the rear axle.
7/28/2022 TML 112

113.  Removal of Park Brake Components
 Inspection of Park Brake Components
 Assembling of Park Brake Components
 Adjustment of Park Brake
 Disassembly of Park Brake (LP /LPT)
 Inspection of Park Brake (LP /LPT)
 Assembly of Park Brake (LP /LPT)
 Adjustment of Park Brake (LP /LPT)
Overhauling & Adjustment of Parking Brake (407)
7/28/2022 TML 113
Overhauling &
Adjustment of Parking
Brake (407)

114. Load Sensing Type Proportioning Valve
Purpose
 This is a special feature of Tata Motor’s
Winger vehicle where there is a large
difference in vehicle weight between laden
and empty conditions. During dynamic
braking, the weight on the rear axle tends
to shift towards the frontal direction of
vehicle resulting into less vertical load on
rear axle which results into rear wheel
locking. LSPV regulates the pressure in the
rear brakes in proportion to the load in
vehicle. Hence it is called as load Sensing
Proportioning Valve.
7/28/2022 TML 114
Main
Spring

115. Load Sensing Type Proportioning Valve
Working of Valve
 Initially the main spring force keeps the
piston pressed in upward direction keeping
outlet port connected to rear circuit open
at seal, till knee point i.e. inlet pressure is
transmitted to the rear circuit through
outlet port without any pressure
regulation.
 Further pressing of brake pedal increases
the inlet pressure to LSPV and in-turn
increases the downward force acting on
the piston. (The downward force is created
by hydraulic pressure available in front
circuit acting on area ‘A’.)
7/28/2022 TML 115

116. Load Sensing Type Proportioning Valve
Working of Valve..
 The downward movement of the piston closes the entry of oil from rear inlet port to outlet
port at sealing point ‘P’.
 At this point there are three forces acting on the piston:
– Upwards force ‘F1’ of main spring.
– Hydraulic force acting on area ‘P’.
– Hydraulic force acting downwards on area ‘A.
 Since the resultant force is positive, the piston lifts upwards and the Oil entered from Inlet
port is fed to Outlet port and the pressure to outlet increases. Further increase in inlet
pressure (due to pressing of brake pedal) again results into downward movement of piston,
thereby closing the outlet at point ‘P’ and results into drop in outlet pressure.
 The process continues and follows a fixed pattern (Called slope characteristic of LSPV).
7/28/2022 TML 116

117. Load Sensing Type Proportioning Valve
Maintenance Precautions
 LSPV is a non-serviceable assembly, and should be replaced, if any problem arises.
– During vehicle servicing control spring setting should be checked and corrected if required with the
help of an ‘Installation gauge’ provided for the purpose. The stretched length of the control spring
should be set at 92.5 mm with the help of installation gauge.
 The correct setting of Control Spring ensures adequate oil pressure to rear circuit and thereby
ensures no skidding of rear wheels.
7/28/2022 TML 117

118. LSPV Setting Procedures – Winger 3200 & 2800
 LSPV setting is done by maintaining the distance of 251mm between nut & long member
 LSPV setting to be done in Unladen condition
 Max. operating pressure 140 Bar
 LSPV Assy. is non serviceable
7/28/2022 TML 118

119.  Removal & Fitment of New Pads
 Dismantling of Caliper
 Inspection of Caliper
 Assembly of Caliper
 Replacement of Sliding pin Kit
 Bleeding of Brake System
Overhauling of Front Brake System (Winger)
7/28/2022 TML 119
Overhauling of Front
Brake System (Winger)

120. Load Conscious Pressure Reducing Valve (LCRV)
 Hydraulic operated load sensing valve is fitted in this vehicle.
 This regulates flow of brake fluid to rear wheel cylinder.
 In un-laden condition, less brake effort is required to avoid skidding of rear wheels & hence
less brake fluid is supplied to rear wheels.
Adjustment
 In Un-laden condition, assemble LCRV link pin in hole ‘B’ of link mounting bracket.
 Set the gap ‘S’ between adjusting screw and plunger can be adjusted by loosening adjusting
screw lock nut and rotating adjusting screw with the help of screwdriver.
 After adjusting the gap, tighten lock nut without disturbing adjusting screw.
 Relocate the link pin in top hole ‘A’ and tighten lock pin nut.
 Adjustment of LCRV should be done as per valve setting data given on the sticker located on
firewall.
7/28/2022 TML 120

121. LCRV Setting
LCRV adjustment procedure in un-laden
condition
 Insert the link pin in hole indicated in the
below table depend on chassis height at
rear axle.
 Tighten the link pin hex nut with tighten
torque of 13.6 to 17.6 Nm.
 Then rotate the LCRV grub screw with Allen
key to maintain the gap of 0.1 mm.
 Then tighten the lock nut of grub screw to
lock it.
7/28/2022 TML 121
Sr. Model Gap Setting in mm Holes Fitted
1 SFC 407/27 0.15 to 0.16 3 A
A
B
C
1
Note:
1. Chassis height (709 ±10)from ground to long member Top in without
modification in Leaf spring in un-laden condition
2. If any of modification in leaf spring LCRV hole to be adjusted as per point 2
& 3
Sr. No.
Chassis height from long member
top to ground at rear axle (Unladen)
with load body
Rear axle to link pin
engage hole location
1 709 ± 10 A
2 790 ± 10 B
3 840 ± 10 C

122. LCRV Setting
LCRV adjustment procedure in un-laden
condition
 Insert the link pin in hole indicated in hole A.
 Then rotate the LCRV grub screw with Allen
key to maintain the gap mention as per chart.
 Then tighten the lock nut of grub screw to
lock it.
 After gap setting insert the link pin in hole B.
7/28/2022 TML 122
Sr. Model Gap setting in mm Holes Fitted
1 LPT 407/34 4.7 to 4.9 2 B
2 LP 410/31 TT wo bus body 10.8 to 11 2 B
3 SFC 407/31TT 2.8 to 3.1 2 B
4 SFC 407/31 Refresh 2.8 to 3.1 2 B
5 SFC 410/31 FES TMML 3.7 to 3.9 2 B
6 LPT 407/34 4.7 to 4.9 2 B
7 LPK 407/27 4.7 to 4.9 2 B
8 SFC 410/27 FES 2.5 to 2.7 2 B
9 XENON 3.0L & 2.2 L 2.7 2 B
A
B
B
A
2 types of LCRV are used in LCV
with hydraulic brakes

123. Load Conscious Pressure Reducing Valve (LCRV)
7/28/2022 TML 123
Sr. No. Model LCRV Gap ‘S’
1 407 SFC BS I/BS II Twin Tyre (Export) 2.8 to 3.1
2 410 SFC single tyre 4.3 to 4.5
3 410 SFC twin tyre 2.8 to 3.1
4 410 SFC faceless bus 27 WB 2.5 to 2.7
5 410 SFC faceless bus 31 WB 3.7 to 3.9
6 410 SFC cowl bus 31 WB 3.7 to 3.9
7 410 SFC twin tyre 1.2 to 1.04
8 407 LPT Ex 34 4.7 to 4.9
9 410 LPT Ex 34 4.7 to 4.9
10 407 LPK 27 WB (with tipper body) 4.0 to 4.2
11 407 LPK 27 WB (without tipper body) 5.8 to 6.0
12 509 M LP LHD (Export) 10.8 to 11.0
13 509 M LPT LHD (Export) 0.5 to 0.7

124. Model with out LCRV
Model with out LCRV :
 XENON RX
 407 SK / HT 31 BS3
 407 SFC / 31 4X4 BS2 / BS3
 407 LP /31 BS 3
 407 LP/31 TT BS 3
 709 SFC / 38 Ex BS3
 909 SFC / 38 Ex BS3
 909 LPT 38 BS2 / BS3 / BS4
 LPT 1109 /42 BS 3/ BS 4/CRDI
 Ultra truck 912/39 BS
 LPO ultra bus 7.5 / 42
 LPO ultra bus 912 / 49
 All LP buses model don't have LCRV fitment.
7/28/2022 TML 124

125.  Disassembly of Foundation Brakes
 Assembly Duo Servo Brake Front
 Assembly Duo Servo Brake Rear
 Inspection
 Assembly of Foundation Brakes
 Bleeding of Service Brake
 Service Brake Adjustment
 Trouble shooting hints for the brake system
Overhauling of Rear Brake System (407)
7/28/2022 TML 125
Overhauling of Rear
Brake System (407)

126. Dual Air Over Hydraulic Brake System (DAOH)
7/28/2022 TML 126

127. DAOH System Layout
7/28/2022 TML 127

128. Components of DAOH
Air Compressor:
 Air compressor is attached to the engine.
Air is admitted inside after air filter. The
crank shaft inside moves the piston which
compresses the incoming air. The entire
system is lubricated by engine oil.
 The reed valve between head and block
opens and close the inlet air and
compressed air. Due to any problem if the
reed valve does not operate, the pressure
gets dropped.
7/28/2022 TML 128

129. Reservoir and Master Cylinder Assy
 The hydraulic master cylinder should be attached to the air cylinder in such a manner that
play exists between the push rod of the Air Cylinder and the piston of the Master Cylinder to
guarantee that the compensating port is not covered by the primary cup.
 A closed compensating port would not permit the return flow of the fluid, which expands
under the influence of heat, to the built-in reservoir.
 The fluid would expand in the direction of the wheel cylinders and would result in constant
grabbing of the brake shoes.
7/28/2022 TML 129

130. Wheel Cylinder
Function
 This transmits the force developed by
hydraulic oil pressure to the brake shoes.
 The hydraulic force on plunger pushes
plunger and hence the brake shoe.
7/28/2022 TML 130

131. Auto Adjuster
 Transmits the force developed by hydraulic oil pressure to the brake shoes. Automatically
adjust gap between brake shoes and brake liner, as brake liner wears out.
7/28/2022 TML 131

132. Rear Brake Exploded View
7/28/2022 TML 132

133. Front Disc Brake Assembly RB 60+60
 There are two plungers in the assy. moves ahead with hydraulic force.
 This pushes the inner caliper towards disc, and then pulls outer caliper. Hence the disc gets
force from both sides.
 This movement is with the help of sliding pin bolts which are covered by rubber cap.
 The restriction of movement of this pin causes brake problems.
 The sealing ring on plunger makes movement of plunger in both directions.
7/28/2022 TML 133

134. Parking Brake – Prop.shaft Mounted
Brake Adjustment Procedure
 Fit the brake drum
 Insert the screw driver through the drum
adjuster hole and rotate the adjuster wheel
and lock the brake drum.
 Now loosen the adjuster wheel till the
drum rotates freely.
 Now adjust the parking brake cable at the
parking brake lever end for 10 clinches.
 Apply parking brake and ensure that the
parking brake lever should not exceed the
notches.
7/28/2022 TML 134
Parking Brakes position on
Vehicle between Gearbox &
Propeller Shaft

135. Fail Safe Brake System
 In case of air pressure drop (below 3.2) bar in service brake tanks, low pressure air switch will
send an electrical signal to Solenoid valve.
 Then solenoid valve actuation will allow safety reservoir air pressure to flow up to Double
Check Valve. At double check valve since air pressure from failsafe reservoir is more, it will
allow air pressure from safety tank up to rear air cylinder & brake will apply automatically till
air pressure in the main tanks will reach up to safe limit.
 In case of air pressure build crosses critical pressure limit this circuit will automatically
releases rear brakes.
 This fail system will work only in condition of vehicle ignition switch is on. Hence will protect
hydraulic side of seals for long duration under pressure.
 This system will work in vehicle running condition also.
 Prior to failsafe application, driver will have low air pressure warning (Visible & audible).
7/28/2022 TML 135

136. Fail Safe Brake System
7/28/2022 TML 136
LP switch with 5.4 bar
LP switch with 3.2 bar

137. Brake System Overhauling - DAOH
7/28/2022 TML 137

138. Caliper Dismantling Procedure
 Park the vehicle on a level surface.
 Apply parking brake.
 Chock the wheels by using wheel stopper.
 Jack up the front wheels by using proper
jacking machine and support the axle by
horse stand.
 Dismantle wheel as per vehicle
manufacturer recommendation.
 Disconnect the pad wear indicator
connection.
Ultra Truck
7/28/2022 TML 138

139. Front Brake Pad Removal
7/28/2022 TML 139
RB
68+68
Remove both the spring clip from
the guide pin.
Remove both the guide pins. Remove both the pads.
RB
60+60
Loosen both the screws. Remove the spring plate. Remove both the pads.

140. Caliper Dismantling
7/28/2022 TML 140
1 2 3
Remove the hose from the vehicle. Remove the hose from the caliper
assembly.
Keep a wooden block in between the
piston and bridge.
Blow low pressure air through the inlet
port till both the piston comes out of
the bore.
4 5 6
Remove both the plunger from the
housing by pulling out by hand as
shown.
Remove both the plunger dust cover
from the housing.
Remove both the sealing rings from
groove with the help of brass screw
driver.

141. Caliper Dismantling
7/28/2022 TML 141
7 8 9
Remove both the protective plug. Fix the caliper in the table fixture as
show.
Remove the bleed screw cap.
10 11 12
Remove the bleed screw. Loosen all the 4 bridge mounting bolts
with the help of Allen key socket.
Hold the bridge and remove all the
bridge mounting bolts.
Remove the bridge from the housing.

142. Caliper Dismantling
7/28/2022 TML 142
13 14 15
Remove the housing assembly from
carrier by sliding upwards.
Remove the boot sliding pin from the
housing.
Loosen both the sliding pin bolt for one
turn with the Allen key socket.
16 17
Discard all below mentioned materials:
CAUTION: Loosen the sliding pin bolt
only at the time of sliding pin
replacement.
Note: Don't use Allen key as it may slip
and damage the bolts
Remove the sliding pin bolt and sliding
pin sleeve assembly from the carrier.
Sealing ring, dust boot, sliding pin boot,
Sliding pin Sleeve Bleed screw cap &
protective plug.

143. Inspection of Components
7/28/2022 TML 143
Wash all the components with fresh brake fluid/ alcohol and wipe with a clean
cloth.
Caliper Housing
Caution: No reconditioning recommended only replacement
• Inspect the caliper housing bore for any pitting corrosion and defects.
• Inspect the bore for sealing ring grove, piston boot groove, sliding pin boot
grooves for abnormalities or damages.
• Inspect the inlet port and bleed screw port for any damage.
• If found any of the defect replace the entire caliper assembly.
Piston
Caution: No reconditioning recommended only replacement
• Inspect the piston for surface appearance.
• If the piston is found damaged or rusted on the outer surface discard the
piston.
• If found any of the defect replace piston.

144. Inspection of Components
7/28/2022 TML 144
Sliding Pin
Caution: No reconditioning recommended only replacement
• Inspect the sliding pins for wear or damages.
• Inspect for any rust or corrosion.
• If found any defect replace both the sliding pins.
Sliding Pin Bore
Caution: No reconditioning recommended only replacement
• Check for any wear, defect or corrosion in the sliding pin bore.
• If found any of the above defect replace the carrier assembly.
Pad Assembly
Caution: No reconditioning recommended only replacement
• Inspect the available lining thickness on the pad back plate.
• If found 2.2 or below replace the pad assembly.
• Caution: Pad assembly to be replaced as an axle set only.

145. Inspection of Components
7/28/2022 TML 145
Spring Plate
Caution: No reconditioning recommended only replacement
• Inspect the pad retainer plate for any damages or bend.
• Inspect for any rust or corrosion.
• If found any defect replace the pad retainer plate.
Pad Guide Plate
Caution: No reconditioning recommended only replacement
• Inspect the pad guide pin for any damages or bend.
• Inspect for any rust or corrosion.
• If found any defect replace the pad guide pin.

146. Removal of Wheel Cylinder from Rear Brake
7/28/2022 TML 146
1. Park the vehicle on a level
surface.
2. Apply parking brake.
3. Chock the wheels by using
wheel stopper.
7. Remove the brake drum
assembly.
4. Jack up the rear wheels
by using proper jack and
support the axle by suitable
stand.
8. Remove the brake shoe
return spring with the help
of special tool.
5. Loosen the wheel nut and
take out the tyre.
6. Use jacking bolt to
remove the brake drum.
9. Compress the both lever
to release the spring tension
so that spring can come out
easily from the brake shoe
holding hole.

147. Removal of Wheel Cylinder from Rear Brake
7/28/2022 TML 147
10. Take out the Spring. 13. Similarly remove the
other side shoe hold down
pin.
11. Remove the other side
spring too with the help of
spring remover and take out
the spring from slot.
14. Remove the shoe hold
down pin along with washer
and spring.
12. Remove the shoe hold
down pin of the leading shoe
with the help of shoe hold
down pin tool.
15. Take out the shoe
assembly out.

148. Removal of Wheel Cylinder from Rear Brake
7/28/2022 TML 148
16. Loosen and remove the
bundy and bridge pipe
connection from the wheel
cylinder.
17. Loosen the wheel
cylinder mounting bolts.
18. Remove the wheel
cylinder from back plate.

149. Assembly of Wheel Cylinder
7/28/2022 TML 149
1. Place the wheel cylinder
in back plate.
2. Fit the wheel cylinder
mounting bolts and tighten
to 60 – 65 Nm.
6. Position the anti rotation
clip as shown. Lift the
leading lined shoe & place
the shoe web in between
the anti rotation clip slot and
hold.
3. Fit the bundy and tighten
to 14 - 18 Nm.
4. Apply a thin film of
graphite grease on the shoe
seating area on back plate.
7. Place the trailing shoe in
position and fit the shoe
hold down pin, spring and
washer.
5. Seat the leading lined
shoe abutment end in
position on the wheel
cylinder shoe slot.
8. Fit shoe return spring in
the leading and trailing shoe
as shown.

150. Assembly of Wheel Cylinder
7/28/2022 TML 150
9. Check for proper seating
of all the components.
10. Fit the brake drum and
wheels.

151. Rear Brake Shoe Adjustment
7/28/2022 TML 151
1. Remove the lining
inspection window
grommet.
4. Insert the adjuster tool
(Special tool) through the
adjuster window.
2. Insert 0.25 mm feeler
gauge in between the drum
and lining.
5. Rotate the adjuster screw
in the opposite direction of
the arrow mark on the back
plate till the drum and lining
touches the feeler gauge.
3. Remove the adjuster
window grommet.
Check for free rotation of drum.
If the drum is not free rotate the adjuster screw by one notch in the
direction of arrow mark at a time till the drum rotates freely. Adjust
the lining to drum clearance to 0.2 – 0.3 mm.
6 Refit both the grommet.
Repeat the same procedure in other wheel cylinders.
Bleed the system as per recommendation

152. Wheel Cylinder Dismantling Procedure
7/28/2022 TML 152
1. Remove the anti rotation
clip with slight pressure.
4. Remove the cam screw
and the copper washer.
2. Loosen and remove the
bleed screw.
5. Remove the plunger
assembly along with the dust
cover.
3. Loosen the cam screw. 6. Remove the spring.

153. Wheel Cylinder Dismantling Procedure
7/28/2022 TML 153
7. Remove the back plunger. 10. Remove the seal from
the back plunger assembly
with the help of brass screw
driver.
8. Remove the dust boot
from the plunger assembly.
11. Remove the wiper seal
with the help of brass screw
driver.
9. Remove the seal from the
plunger assembly with the
help of blunt brass screw
driver.
12. Loosen and remove the
adjuster screw.
13. Remove the excluder
boot from the plunger
assembly.

154. Wheel Cylinder Assembly
7/28/2022 TML 154
1. Wash all the internal
components with fresh
brake fluid and wipe with a
clean cloth.
4. Fit the seal in the groove
of the back plunger.
Note: Take care of the seal
lip direction it should be
away.
2. Dip all the internal
components in fresh brake
fluid.
5. Fit the seal in the groove
of the plunger assembly.
Note: Take care of the seal
lip direction it should be
away.
3. Fit the wiper seal in the
step on the back plunger.
6. Clean the adjuster thread
and adjuster.

155. Wheel Cylinder Assembly
7/28/2022 TML 155
7. Apply a thin film of
Molicote grease to the
thread of adjuster screw.
10. Fit the adjuster screw in
the adjuster.
8. Insert the excluder
assembly in the excluder
guide.
11. Tighten the adjuster
screw up to step in excluder
press tool a shown.
9. Fit the adjuster screw in
the guide tool and fit the
excluder assembly in the
groove of the adjuster screw.
12. Insert the adjuster screw
in the slot of the excluder
press tool as shown.

156. Wheel Cylinder Assembly
7/28/2022 TML 156
13. Support the plunger with
wooden blocks.
16. Smear the wheel cylinder
bore with fresh brake fluid.
14. Tap the excluder press
tool with mallet till there is
no gap between the excluder
assembly and adjuster.
17. Fit the back plunger assy
as the seal leads into the
bore.
15. Fit the dust boot in the
groove of the adjuster in the
plunger assembly.
18. Fit the spring.

157. Wheel Cylinder Assembly
7/28/2022 TML 157
19. Fit the plunger assembly
in the bore.
22. Tighten screw to 16- 18
Nm.
20. Fit the dust cover in the
groove of the wheel cylinder.
23. Fit the bleed screw and
tighten to 7 - 10 Nm.
21. Fit the washer and screw
in the cam screw groove.
24. Fit the anti rotation clip
on the adjusting screw.

158. Park Brake Setting
 New parking brake cable should be
inserted near gear box.
 Ensure that while fitting parking brake
cable at drum side on gear box not to be
stretched & matching eye hole of parking
cable after that fit circlip on joint.
 To adjust 8-10 notches at handbrake lever
end in cabin setting to be done by
adjusting nut of parking cable.
7/28/2022 TML 158

159. LCRV Adjustment
LCRV adjustment procedure in un-laden condition
1. Remove the link rod from the bracket hole A.
2. Now check the gap between the adjuster and valve plunger & if required adjust as per chart.
3. Hold the adjuster nut in the adjusted position and tighten the locknut to 14 - 17 Nm.
4. Remove the link rod and fit it in the middle Hole B.
7/28/2022 TML 159
Sr No. Model Gap Setting in mm (with load body) Holes Fitted
1 Ultra 812/33 3 3 B
2 Ultra 912/33 4 3 B
A
B
C
A
B C

160. General Information
Suspension System - 709 Type,
Coil spring & Macpherson, parabolic, Torsion bar
Double wishbone type suspension systems
7/28/2022 TML 160

161. Model Matrix - LCV
7/28/2022 TML 161
Model Winger
Xenon
RX
Xenon
2.2L/ 3.0L
SFC / LPK
/ LPT 407,
LPT 410
SFC 709
/ 909,
LPK 909
Ultra Bus
712 / 912 /
812
Ultra
truck 912
/ 812
LPT
1109
LPT
1613
TC
LPT
2518TC
Independent Front
Macpherson
front
Torsion
bar
Semi elliptic
Front      
Rear        
Parabolic
Front  
Rear  

162. Application of Types of Suspension - LCV
7/28/2022 TML 162
Leaf Spring type
Front : Single
Rear : With Helper Spring
Air Suspension Combination:
Front : Independent McPherson,
Rear : Parabolic Spring
Combination:
Front : Independent Torsion Bar,
Rear : Parabolic Spring
Leaf Spring type
Front : Single
Rear : Two single springs
Bogie Type suspension

163. Leaf Spring Measurable Dimensions
7/28/2022 TML 163

164. Antiroll Bar Suspension
 It helps reduce the body roll of a vehicle
during fast cornering or over road
irregularities.
 Anti roll bar connects the bar to control
arm.
 Bar twists, resisting movement of lower
control arm.
 Flexible bushings attach it to the chassis.
Also visible on the right is one of the links
which connect the bar to the suspension
(drop link). These twist the anti-roll bar
when the vehicle is cornering, resisting
body roll.
 Increases the suspension's rolls stiffness—
its resistance to roll in turns, independent
of its spring rate in the vertical direction.
7/28/2022 TML 164

165. Suspension Parts
7/28/2022 TML 165
Leaf Spring with Helper Spring.
Parabolic Spring Multi Axle Spring Suspension

166. Comparison between Parabolic & Multileaf
Parabolic springs
 Few number of leaves (4-5 Max)
 All leaves Full length Leaves.
 Leaves do not touch each other except at
center and end hence no friction between
leaves.
 Leaf thickness reduces from center
towards end parabolically.
Multi-leaf Springs
 More number of leaves (6-8 minimum)
 Leaf length reduces from top to bottom.
 Leaves are in contact with each other.
 Leaf thickness constant along the length.
 Interleaf friction present.
7/28/2022 TML 166

167. Parabolic Spring – Advantages & Limitations
Advantages
 Improved ride comfort and handling.
 Weight reduction Hence less unsprung
mass.
 Higher life because of the improved
process.
Limitations
 Each leaf is considered as a separate spring
& made with different camber & hence the
leaf to be replaced by the same leaf.
 Ex. Forth leaf can not be replaced by 3rd
leaf. Or forth leaf can not be added as extra
fifth leaf. Multileaf leaves can not be added
in the parabolic spring.
 Shock Absorbers are mandatory with
parabolic springs.
7/28/2022 TML 167

168. Suspension System - Winger
Front: Macpherson strut, Lower Wish, Anti roll bar
 This is a combined coil spring and shock absorber assembly.
 The upper pivot is the strut mounting to the frame.
 A ball bearing mounting at the top allows steering movements.
 Bump stops or rebound bumpers prevent metal-to-metal contact.
 The shock absorber is inside the strut.
 The lower spring seat is part of the shock absorber body.
 Metal strut tube houses shock absorber reservoir, valve, pressure tube etc.
7/28/2022 TML 168

169. Suspension System - Winger
Front: Macpherson strut, Lower Wish, Anti roll bar
7/28/2022 TML 169
Sr. No. Description
1 Assembly front strut complete
2 Cover top cup assembly
3 Nyloc nut
4 Top retaining cup
5 Spacer
6 Washer
7 Protector nut top cup assembly
8 Nyloc nut
9 Bright washer
10 Assembly top cup
11 Spring seat top
12 Bump stop
13 Hose clamp
14 Dust cover
15 Spring
16 Assembly front strut

170. Suspension System - Winger
Rear: Parabolic type leaf spring, Shock absorber, anti-roll
 Leaf springs control side sway.
 A large amount of un-sprung weight is taken.
 Take up a lot of Rear load on rough roads.
7/28/2022 TML 170

171. Suspension System - Winger
Rear: Parabolic type leaf spring, Shock
absorber, anti-roll
7/28/2022 TML 171
Sr. No. Description
1 Spring assembly 1 and 2 rear
2 Rear clamp
3 Rear 2nd leaf
4 Rear tip insert
5 Shim rear spring
6 Rear tip insert
7 Nyloc nut
8 Washer
9 Spring pin front
10 Rear 1st leaf
11 Outer bush
12 U-bolt
13 Guide plate
14 Shim rear spring
15 Strip rear spring mounting
16 Nyloc nut
17 Spring pin rear
18 Bush (Spring pin rear)

172. Double Wishbone Type - 207
Front Suspension
1. Lower wishbone with two arm is fitted in
place of single arm link.
2. Shock absorber mounted on lower
wishbone out side coil spring instead of
inside coil spring.
3. Antiroll bar fitted on lower wishbone
instead of frame mounting with
connecting rod.
4. Brake rod eliminated.
5. Rear antiroll bar eliminated.
6. Parabolic type Rear springs.
7/28/2022 TML 172

173. Double Wishbone Type - 207
Rear Suspension
 Each wheel has a separate suspension unit.
Wheels are connected to chassis in such a
manner that the rise and fall of one wheel
has no direct effect on the other.
 Open end of upper wishbone is mounted on
chassis long member through a spindle and
pivoted bushes. Closed end of upper
wishbone is connected to top of stub axle by
a ball joint.
 Lower wishbone is pivoted to chassis frame.
 Front end of torsion bar is connected to
lower wishbone with bracket at rear pivot pin
and rear end to torsion bar adjustment lever
connected at cross member.
 Ball joint on lower wishbone is connected to
bottom end of stub axle.
Improved ride comfort and handling
7/28/2022 TML 173

174. Maintenance of Double Wishbone Type Suspension
7/28/2022 TML 174
1 Press the two wishbones by using tool, &
remove the stub axle from Wishbone.
2 Using puller take out the stub axle ball joint.
3 Using puller take out the assembly bush from
wishbone link.
STEP 1
Press the two
wishbones by using
tool, & remove the
stub axle from
Wishbone
STEP 2
Using puller
take out the
stub axle
ball joint
STEP 3
Using
puller take
out the
Assy bush
from
wishbone
link

175. Maintenance of Double Wishbone Type Suspension
7/28/2022 TML 175
4 Hammer with the tool to fit the ball joint to
stub axle.
5 Using Tool, fit the clip ring for rubber boot on
ball joint.
6 Using Tool, fit the bush on lower link.
Again reassemble the wishbone set by using
tool.
STEP 4
Hammer with the
tool to fit the ball
joint to stub axle

176. Torsion Bar Suspension - Xenon
Front Suspension
 Torsion bar spring is used in front suspension with wide upper and lower wishbones. Torsion
bar preload can be adjusted by adjusting screws provided at rear end of torsion bar. Wheel
alignment is by means of shims provided on upper wishbone.
 Supports the vehicle weight and absorbs the road shock.
 Performs the same function as a coil spring.
 Supports the vehicle's weight.
7/28/2022 TML 176
Wheel
Stub axle
Lower
Wishbone
Torsion Bar
Bolts on
chassis
Shock
absorber

177. Torsion Bar Suspension - Xenon
Rear Suspension
 Each wheel has a separate suspension unit.
Wheels are connected to chassis in such a
manner that the rise and fall of one wheel
has no direct effect on the other.
 Open end of upper wishbone is mounted on
chassis long member through a spindle and
pivoted bushes. Closed end of upper
wishbone is connected to top of stub axle by
a ball joint.
 Lower wishbone is pivoted to chassis frame.
 Front end of torsion bar is connected to
lower wishbone with bracket at rear pivot pin
and rear end to torsion bar adjustment lever
connected at cross member.
 Ball joint on lower wishbone is connected to
bottom end of stub axle.
7/28/2022 TML 177

178. Independent Suspension
Shock Absorber
 Function:
– To control unwanted motion. i.e. Damping.
– To provide safe control of a necessary
motion.
– To provide measured response to given
energy input.
7/28/2022 TML 178

179. Shock Absorber Inspection
 Perform a visual inspection for damage, rubber bushing wear or oil leakage.
 Perform a shock absorber bounce test
– Push down on one corner of the vehicle
– Release the body
– Count the number of times the body rebounds
– Maximum two or three oscillations
 This Shock absorber cannot be repaired & needs to be replaced
7/28/2022 TML 179

180. Suspension System - Ultra
Front suspension Rear suspension
7/28/2022 TML 180
Shackle
Anti roll bar
Shackle
U clamp
Shock absorber Shock absorber

181. Suspension System - Ultra
 Parabolic Spring is a spring that consists of two or more leaves.
 The leaves touch only in the center, where they are fixed to the axle and at the outer ends,
where they are fixed to the vehicle. In between those two points the leaves do not touch
each other as they do with conventional leaf springs.
 Every single leaf will have, more or less, the shape of a complete multi leaf spring and thus it's
capable to cope with the same forces.
 Each leaf represents a complete spring in it's self and will act as such. To enable this the leaf is
tapered, from the center (thick) to the outer ends (thin). This tapering is parabolic, it means
that every centimeter (or inch) the thickness of the leaf decreases in an amount that relates
to the square function of it's length.
 In Parabolic leaf spring semi elliptic type leaf spring should not be added.
7/28/2022 TML 181

182. Suspension System -1109
Grading based on Camber
 Earlier leaf spring were graded on Camber in no load condition from eye to eye
7/28/2022 TML 182
Grading - 0 +
Camber
valve
186 187 188 189 190 191 192 193 194

183. Suspension System -1109
Additional grading based on Half span
 Half spring span is distance between Spring eye & Center bolt in vehicle forward direction as
shown in figure.
 Spring are graded in A, B, C grade.
 Same grade leaf spring are fitted on a particular vehicle.
7/28/2022 TML 183
Gradation of leaf spring is done as:
Grade A 789.5 mm to 790.5 mm
Grade B 790.5 mm to 791.5 mm
Grade C 791.5 mm to 792.5 mm

184. Castor Plate in Leaf Spring
Caster plate in front axle
 Caster plate is part of only front leaf spring
assembly. There is no caster plate at rear
leaf spring One leaf spring has only one
caster plate.
 The dimensions given are thickness of
caster plate in mm
7/28/2022 TML 184
Sr. no Model
Castor plate thickness in mm
front end of
caster plate
Rear end of
caster plate
1 407
Pickup No castor plate
SFC 2 7
LPT 2 7
LP 2 7
2 709
SFC 2 10
LPT 2 10
LP 2 10
3 909
SFC 2 10
LPT 2 10
LP 2 10
4 1109
SFC 8 4
LPT 8 4
LP 13 2

185. Ride Heights
 This is a distance between Bump stop and
chassis frame as shown in fig.
 All suspension systems have a limit of
travel. If the vehicle hits a large bump in
the road, the wheels are forced upward
toward the vehicle with tremendous force.
7/28/2022 TML 185

186. Ride Heights
7/28/2022 TML 186
Sr.
No.
Model
Front Rear Front leaf spring Rear leaf spring in mm
Load in kg Load in kg
Ride gap at Driver (LH) in mm
Tolerance = ± 7 mm
Ride gap at Co driver (RH) in mm
Tolerance = ± 7 mm
Ride gap in mm
Tolerance = ± 7 mm
Unladen Laden Unladen Laden Unladen Rated load Unladen Rated load Unladen Rated load
1 SFC 407 pickup 27WB 1250 2050 990 2400 72 22 72 22 99 69
2 SFC 407 31WB ST 1443 2300 1083 3650 106 59 106 59 121 67
3
SFC 407 31 WB HT & SK
TT
1510 1850 1820 4400 57 35 57 35 86 56
4 LPT 407 34 WB EX 1775 2585 1075 3665 90 60 90 60 75 35
5 LPT 407 34 WB EX2 1775 3600 2125 4060 83 38 83 38 75 35
7 LP 407 31 WB TT 2172 2400 2509 3200 71 58 71 58 105 86
8 LP410 34 WB TT 1660 2150 2190 3960 93 60 93 60 106 48
9 SFC 709 1650 2400 1490 5100 75 42 75 42 67 26
10 LPT 709 38Wb Ex2 1947 2645 1365 4700 85 59 85 59 71 29
11 LP 709 34/38 WB 2230 2630 2200 4700 120 99 120 99 105 26
12 LPT 909 HD 2015 2950 1600 6350 80 51 80 51 97 43
13 LP 912 49WB 2850 3250 2633 6350 76 63 76 63 119 58
14 LPK 909 2015 2950 1600 6350 80 51 80 51 97 43
15 LPT 1109 Ex2 36 WB 2625 4670 2451 8320 104 58 104 58 133 79
16 LPT 1109 Ex2 42 WB 2625 4670 2451 8320 104 58 104 58 133 79

187. Torsion Bar Overhauling
7/28/2022 TML 187
Loosen torsion bar anchor
bolts to release torsion bar
load fully.
• Remove torsion bar .
• Torsion bar with ‘L’ mark
to be fitted at LHS and
‘R’ mark at RHS.
• Bring height at top of
chassis frame (at Front axle
location hole to 530+/-3
mm).
• Assemble levers at torsion
bar such that after putting
1 nut, 1 to 3 mm
protrusion of anchor bolt is
maintained.
• Tighten nut to 71 to 74
mm protrusion of
anchor bolt.

188. Torsion Bar Suspension Adjustments
Xenon – Wheel Alignment
 Before adjusting the wheel alignment on the vehicle chassis height needs to be adjusted as
per the procedure given below:
1. Vehicle should be Unladen and parked on level surface.
2. Front tyre should have inflated to correct pressure.
3. While adjusting the Chassis Height nobody should sit inside the vehicle.
4. Measure the Chassis Height from Ground to the Frame.(Near Bump stop bracket).
5. It should be 530 mm.
 Chassis Height Adjustment
7/28/2022 TML 188

189. Torsion Bar Suspension Adjustments
Camber Adjustment
 Adding shims reduces camber and vice
versa.
 A 1mm Shim addition/deletion reduces/
increases camber value by ~11’
 Camber: 00 ±30’
Caster Adjustment
 Adding Caster Shims in rear side of Top
wishbone reduces caster.
 Adding Caster Shims in front side of Top
wishbone increases caster.
 A 0.8mm Shim addition/deletion
reduces/increases camber value by ~16’
 Caster: 30 ±30
7/28/2022 TML 189
Shim

190. Torsion Bar Suspension Adjustments
Toe in Adjustment
 I Toe in: 2-5 mm, Individual Toe in: 2mm Max, Total Toe acceptable Variation: 5mm.
7/28/2022 TML 190

191. Wishbone Overhauling
7/28/2022 TML 191
Remove torsion bar loosen the upper wishbone mounting nuts
loosen the pivot bush nuts on lower wishbone Before tightening pivot bush screws, keep upper wishbone
spindle at 22 deg. This will evenly load the pivot bushes in
both directions.

192. MacPherson Strut Overhauling- Winger
Winger suspension
 Type: Independent suspension, stub axle
and hub.
 Height of coil spring: 339mm (28WB) &
348mm (32WB).
7/28/2022 TML 192
Step 1 :
Remove top bolts
from body.
Step 2 :
Compress
spring with
tool.
Step 3 :
Take out top bolt.

193. Semi Elliptic Type Leaf Spring Dismantling
Steps : Front spring
 Jack up the front axle and support the frame
under frame long member behind front spring,
such that there is no load on spring pins.
 Unscrew and remove the antiroll bar (if fitted)
mounting bolts and ‘U’ bolts of antiroll bar.
 Take out the antiroll bar.
 Unscrew and remove ‘U’ bolt lock nuts and nuts.
 Take out the ‘U’ bolts. Remove guide plates &
rubber buffer.
 Unscrew and remove the bolts and nuts and
locking plates of the spring pins on the spring
hanger bracket and spring shackle. Take out the
spring pins by gently tapping.
 Take out the sealing rings.
 Remove the front spring assembly.
 Remove the caster plate.
7/28/2022 TML 193
Fixture 2574
5890 42 01
Puller
264158903201

194. Semi Elliptic Type Leaf Spring Dismantling
Inspection
Check condition of the following components, if found worn out / damaged, replace them.
1. Front and rear springs, for any broken leaves, etc.
2. Spring eye bushes.
3. Spring hanger bracket and shackles.
4. Sealing rings.
5. Spring pins - check surface condition & threads.
6. Shock absorbers - Check for leakage etc., check the condition of bushes. Pull out the shock
absorber and check the resistance force exists.
7. Spring U bolt/ U bolt threads.
8. Front & rear spring rubber buffer.
9. Antiroll bars (if fitted).
10. Connecting rod, connecting links for antiroll bars (if fitted).
11. Rubber bushes, bearing block.
12. U bolts for antiroll bar mounting.
7/28/2022 TML 194

195. Dos & Don’ts of leaf Spring Suspension
Do’s
1. Leaf spring suspension: Always open the
set of leaf springs with special tools, use
tool for removing spring pins.
2. Always apply grease on the spring leaf
before assy.
3. For Coil spring suspension: Always open
the coil springs after using special tool.
4. Use same mark of rubber boots below
double wishbone coils, coil springs of
same colour. See the marks on parts.
5. Use special tool for opening ball joints of
steering linkages.
6. Grease the points as per schedule.
7. Apply specified torque for U bolts etc.
Don’ts
 Never add spring leaf in set of springs.
 Do not open shock absorbers and never fill
the oil in shock absorbers.
7/28/2022 TML 195

196. Technical Specifications - 407
7/28/2022 TML 196
Truck Bus
LPT 407 /34 LPK 407 SFC 407 ST/TT LP 407/509 TT SFC 407 SFC 407 Faceless
Front Suspension (407)
Type Semi - Elliptic multi leaf
Mounting Fixed pin at front & shackle at rear
Span (mm) 1220 ± 3 1150 ± 3 1220 ± 3 1220 ± 3 1220 ± 3 1220 ± 3
Centre bolt to eye (mm) 610 575 610 610 610 610
No load assembly
128 ± 4 for driver
side & 105 ± 4 for
co-driver side
114 ± for driver
side & 95 ± 4 for
co-driver side
132 ± 4 132 & 145.5 ± 4 103 112.5
Bush inside dia (mm) 20.170/20.040 20.170/20.040 20.170/20.040 20.170/20.040 20.170/20.040 20.170/20.040
Pin dia (mm) 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972
No of leaves 9 12
11 for 410 & 10
for 407
11 7 9
Leaf width (mm) 70 70 70 70 70 70
Leaf thickness (mm) 8 8
7 for 410 & 8 for
407
7 7 7

197. Technical Specifications - 407
7/28/2022 TML 197
Front Shock Absorbers
Type Hydraulic telescopic double acting
Dia 63.5 mm
Stroke 281 mm
Extended length 705 ± 3 mm
Closed length 424 ± 3 mm
Damping force at 0.52 m/sec
piston speed
Compression 50 kg
Extension 300 kg

198. Technical Specifications - 407
7/28/2022 TML 198
Truck Bus
LPT 407 /34 LPK 407 SFC 407 ST/TT LP 407/509 TT SFC 407 SFC 407 Faceless
Rear Suspension (407)
Type Semi - Elliptic multi leaf
Mounting Fixed pin at front & shackle at rear
Span (mm) 1220 ± 3 1220 ± 3 1370 ± 3 1370 ± 3 1370 ± 3 1370 ± 3
Centre bolt to eye (mm) 610 610 685 685 685 685
No load assembly camber
(mm)
74 for main & 40 ± 2
for Auxiliary
74 for main & 0 for
Auxiliary
125 for ST & 98
for TT
90 57.5 90
Bush inside dia (mm) 20.170/20.040 20.170/20.040 20.170/20.040 20.170/20.040 20.170/20.040 20.170/20.040
Pin dia (mm) 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972
No of leaves
7 for main & 4 for
Auxiliary
7 for main & 4 for
Auxiliary
8 for ST & 9 for
TT
11 11 11
Leaf width (mm) 70 70 70 70 70 70
Leaf thickness (mm)
11 for main & 7 for
Auxiliary
11 for main & 7 for
Auxiliary
12 for ST
13 for TT
10 10 10

199. Technical Specifications - 407
7/28/2022 TML 199
Rear Shock Absorbers
Type Hydraulic telescopic double acting
Dia 63.5 mm
Stroke 242 mm
Extended length 620 ± 3 mm
Closed length 378 ± 3 mm
Damping force at 0.52 m/sec
piston speed
Compression 50 kg
Extension 300 kg

200. Technical Specifications - 410
7/28/2022 TML 200
SFC 410 S.T./T.T. LP 410
Front Suspension (410)
Type Semi elliptic multi leaf spring
Mounting Fixed pin at front & shackle at rear
Span (mm) 1220 ± 3 1220 ± 3
Centre bolt to eye (mm) 610 ± 1.5 610 ± 1.5
No load assembly 145.5 ± 4 for driver side & 132.5 for co-driver side
Bush inside dia (mm) 20.170/20.040 20.170/20.040
Pin dia (mm) 19.993 / 19.972 19.993 / 19.972
No of leaves 11 11
Leaf width (mm) 70 70
Leaf thickness (mm) 7 7

201. Technical Specifications - 410
7/28/2022 TML 201
Front Shock Absorbers
SFC 410 S.T./T.T. LP 410
Type
Hydraulic telescopic
double acting
Hydraulic telescopic
double acting
Dia (mm) 55.6 55.56
Stroke (mm) 245 255
Extended length (mm) 620 ± 3 640 ± 3
Closed length (mm) 375 ± 3 385 ± 3
Damping force at 0.52
m/sec piston speed
Compression 50 kg 50 kg
Extension 220 kg 220 kg

202. Technical Specifications - 410
7/28/2022 TML 202
SFC 410 S.T./T.T. SFC 410 S.T. LP 410
Rear Suspension (410)
Type Semi elliptic multi leaf spring
Mounting Fixed pin at front & shackle at rear
Span (mm) 1370 ± 3 1370 ± 3 1370 ± 3
Centre bolt to eye (mm) 685 ± 1.5 685 ± 1.5 685 ± 1.5
No load assembly camber
(mm)
98 ± 3 125 ± 4 103 ± 4
Bush inside dia (mm) 20.170/20.040 20.170/20.040 20.170/20.040
Pin dia (mm) 19.993 / 19.972 19.993 / 19.972 19.993 / 19.972
No of leaves 9 9 11
Leaf width (mm) 70 70 70
Leaf thickness (mm) 6 X 13 thick & 3X17 thick 12 10

203. Technical Specifications - 410
7/28/2022 TML 203
Rear Shock Absorbers
SFC 410 T.T. SFC 410 S.T. LP 410
Type
Hydraulic telescopic
double acting
Hydraulic telescopic
double acting
Hydraulic telescopic
double acting
Dia (mm) 55.6 63.5 55.56
Stroke (mm) 240 237 240
Extended length (mm) 606 ± 3 623 ± 3 606 ± 3
Closed length (mm) 366 ± 3 386 ± 3 366 ± 3
Damping force at
0.52 m/sec piston
speed
Compression 30 kg 30 kg 30 kg
Extension 305 kg 310 kg 305 kg

204. Technical Specifications - 709
7/28/2022 TML 204
Front and rear spring
Semi-elliptic multi-leaf fixed pin at front end and shackle at rear end for both
front and rear springs
Front Rear
LPT 709 SFC 709 LP 709
LPT 709
Main Aux.
SFC 709
Main Aux.
LP 709
Span
Free condition mm
Flat condition mm
(under load)
1124
1150
1212
1255
1410
1450
1207 740
1220
1207 740
1220
1571
1620
No. of leaves Nos.
9 + 1
Spacer
leaf
10
10 + 1
Spacer
leaf
7 7 7 7 8
Thickness mm 8 8 8 11 8 11 8
11 (1 to 6)
17 (7 & 8)