This document describes a quality improvement project conducted by Mahindra to address brake bleeding issues in ALFA 3 Wheeler vehicles. A cross-functional team was formed to investigate the problem, which was causing over 3000 defective vehicles between 2011-2012. The team analyzed possible causes and selected 6 root causes to test, including issues with the brake bleeding machine, TMC mounting brackets, and dimensional variations. The goal of the project was to eliminate brake bleeding related defects within 6 months by January 2013.

1. 1
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
Concern Resolution Process
for In-house Manufacturing
QC Story

2. 2
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
QC STORY PROJECT
PROJECT TITLE :-
Elimination of V1+ Concern of Brake bleeding related issues in ALFA 3
Wheeler Assembly (A long pending V1+ concern)
Mahindra and Mahindra Ltd, Zaheerabad Plant, Vehicle PU
Plan Actual
Start Date 25/06/12 25/06/12
Completion
Date
29/11/12 27/12/12
Current Status:
COMPLETED

3. 3
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
Phase II – QC Story
• Team Information
 Step1: Select the Theme
 Step 2: Justify the choice
 Step 3: Understand the current situation
 Step 4: Select Targets
 Step 5: Analysis (Level 1 Analysis)
 Step 6: Implement corrective measures
 Step 7: Confirm the Effects
 Step 8: Standardize
 Step 9: Summarize & Plan future actions
• Guidelines to user

4. 4
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
Cross Functional Team
No Description Name Designation Dept Email
1 Team Leader K. Vamsi Krishna Graduate
Engineering Trainee
Vehicle PU
(MQA)
620462@mahindra.com
2 Mentor Mr. Abburi Purna Asst Manager Vehicle
PU(MQA)
23075380@mahindra.com
3 Member 1 D Suresh Manager-Mfg
Quality
Vehicle
PU(MQA)
205763@mahindra.com
4 Member 2 K Chakravarthy Manager-
Production
Vehicle PU 205755@mahindra.com
5 Member 3 K Chaitanya
Kumar
Asst Manager Vehicle PU 23066128@mahindra.com
6 Member 4 Gr suresh Dy. Manager-
Production
Vehicle PU 208981@mahindra.com
7 Member 4 Sateesh
Jampana
Asst Manager Industrial
Engineering
23061532@mahindra.com
8 Member 5 V.G.S. Prasad Dy Manager SQA 209690@mahindra.com
9 Member 6 Bhanu Prakash Asst Manager SQA 23069691@mahindra.com

5. 5
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
1. Select the Theme
Brief description of Problem
3271 vehicles were caught as defective units due to poor brake
application in ALFA 3 wheeler all models reported by the stage
operator after brake bleeding and also by the Buy off inspectors
since F-11
What: Brake bleeding issues
Where: In all Alfa 3 Wheeler models
When: Identified after brake bleeding
Who: Reported by the stage operator and intermediate Buy Off
operators
Why:
How: * It got noticed during the inspection at buy off stage
* 3271 vehicles have undergone manual brake bleeding sinceF-11

6. 6
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
1. Select the Theme
How much:
Rework time: 20 Min Per veh,
Manpower required: 2 persons
Rework time: 20 min per veh
Rework cost for brake bleeding on1 veh: Rs.35
Total rework cost to do rework of 2482 vehs’ is = 35*2482= INR 86,870
4550
4025 3780
4375
3990
3675
4200
4620
5530
8330
7595
8925
8190
7735
7350
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
APR'11 MAY'11 JUNE'11 JULY'11 AUG'11 SEP'11 OCT'11 NOV'11 DEC'11 Jan'12 Feb'12 Mar'12 Apr'12 May'12 Jun'12
COPQ(in Rs)

7. 7
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
Finance Approval letter

8. 8
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
2a. Justify the choice (reasons)
PARETO OF BRAKE BLEEDING RELATED CONCERNS FROM
PERIOD Apr’11 TO Jun’12
• Vehicles undergoing rework due to Brake bleeding issues were very high (Apr’11 to Jun’12- High Occurrence) : 2482
• High severity rating: 10
2482
1655
741 520 425 324 290 125 97 76 55 51 33 29 27 26 25 23 22
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
0
1000
2000
3000
4000
5000
6000
7000
Occurence
Trivial many
Vital Few

9. 9
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
2b. Immediate Containment Action
• Manual Brake Bleeding done at Rework Area

10. 10
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
3. Understand the current situation
• Operator Working as per SOP
• Bleeding not ok Veh is detected by operator at
stage and inspector at buyoff
L0 analysis carried out and found O.K
Observations of conformity Analysis.
GOOD POINTS
NOT GOOD POINTS
• Repetitive concern(V1+concern)
• Failure mode not identified

11. 11
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
Vacuuming
Set Value: 0.3 m bar
Vacuum Leak Check
Re-vacuuming
Filling
Set Value: 4 Bar Pressure
Leveling
(Levels the quantity of
Brake fluid till the mark
On TMC)
Process COMPLETE
Found OK
Found Not Ok
Front flexible
hose torquing
(18Nm)
Tightening of
TMC mtg bolts
(22.5Nm)
Pass the Vehicle
to next stage
Re-check for the
Leaks at all the joints
Of loop
Placing of
adopter over the
TMC head and
lock it to the stoppers
Press the green
button and start
the Brake bleeding
Machine automatically
Re-Torque to
all the joints
OK
NOTOK
Manual Process for Brake Bleeding
Process flow inside Brake Bleeding Machine
3. Understand the current situation
Defect
Generation

12. 12
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
3. Understand the current situation
Occurrence Trend from F'11, F,12 & F'13(Apr’12 to Jun’12) concern wise
423
166 200
1207
393
217
420
150 95
0
200
400
600
800
1000
1200
1400
Brake Bleeding
not done
Brake bleeding
not ok
Brake pedal
travel more
F'11
F'12
F'13
Description of brake bleeding concerns
 Brake bleeding not done – V1+
 Brake bleeding not okay – V1+
 Brake pedal travel more – V1+

13. 13
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
3. Understand the current situation
Quality indicators Effected (FB0)
S.No Concern
DATE
ATTR
Buyoff
Location
TOTAL
F-11 FBO
EFFECTED
IN %
TOTAL F-
12 FBO
EFFECTED
IN %
TOTAL:
APR'12
to
JUN’12
(F13)
TOTAL FBO
EFFECTED IN
%PASS 24556 25336 5840
LC 10658 11891 4350
TOTAL 35214 37227 10190
1 Brake bleeding not ok CFT 1ST 166 0.47% 393 1.06% 150 2.20%
2 Brake pedal travel more CFT 1ST 200 0.57% 217 0.58% 95 1.40%
3 Brake bleeding not done CFT 1ST 423 1.20% 1207 3.24% 420 6.30%
Total 789 2.24% 1817 4.88% 665 9.90%
• The above table clearly shows that FBO Effected in F-11, F12 and F13 due
to these issues is very high
• Defect per vehicles increased
• Quality effected
• Manual brake bleeding leads to brake inefficiency which leads to customer
dissatisfaction

14. 14
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
4. Select Target
Present
Level:
Target:
Avg. of 230 vehicles occurrence from Jan’12 to Jun’12
Zero Defect in next 6 months, i.e. Jan’13
Identify the target: Target is the number indicating level of improvement to be achieved
238
217
255
234
221 210
0
0
50
100
150
200
250
300
Jan'12 Feb'12 Mar'12 Apr'12 May'12 Jun'12 JAN'13
Brake Bleeding related issues(Occurrence/Month))

15. 15
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis 5.1 Identify possible causes:
1. SOP not followed
2. Incomplete fitment of previous operation
3. NVA movements
4. Operator skill
5. Operator stress condition
6. New operator at stage
7. Wrong Bundy tube assembled
8. Torque wrench end worn out
9. Motor HP is insufficient
10. Vacuuming pressure not maintained
11. Brake bleeding pressure not achieved
12. Leak detection poor
13. TMC vacuum leakage
14. Bundy tube inside passage block
15. TMC flange face to shackle hole center dimensional variation
16. Wrong fitment sequence for brake adjustments
17. T-joint wrong thread assembled
18. Key point miss in SOP
19. TMC Mtg brackets distance fired
20. Process time not sufficient
21. Brake fluid level less
22. Less torque applied
23. No of operations more
24. Inadequate SOP
25. Brake stud position wrong
26. TMC Brkt cross welded
27. TMC Brkt hole offset
28. Brake fluid less viscous
29. TMC inside passage hole miss
30. Wheel brake cylinder rubber cut
Brain storming session done on basis of past
experience and Gemba transformation

16. 16
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
5.1 Identify possible causes:
Man Method
Machine Material
BRAKEBLEEDINGREALTEDISSUES
Process time not
sufficient
SOP not followed
TMC Brkt cross welded
TMC Mtg brackets distance
fired
No of operations more
Leak detection poor
Wrong fitment sequence for
brake adjustments
TMC Vacuum leakage
Inadequate SOPKey point miss in
SOP
NVA movements
Brake stud
position wrong
Brake bleeding
pressure not achieved
Vacuuming pressure not
maintained
TMC brkt hole offset
Operator skill
New operator at stage
Incomplete fitment of previous
operation
Operator stress condition
Wrong Bundy tube assembled
TMC flange face to shackle
hole center dimensional
variation
Brake fluid level less
Motor HP is insufficient
Brake fluid less viscous
TMC inside passage hole miss
Wheel brake cylinder rubber cut
Bundy tube inside passage block
Less torque applied
Torque wrench end worn out
T-joint wrong thread
assembled

17. 17
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
5.1 Identify possible causes:
Man Method
Machine Material
BRAKEBLEEDINGREALATEDISSUES
Process time not
sufficient
SOP not followed
TMC Brkt cross welded
TMC Mtg brackets distance
fired
No of operations more
Leak detection poor-Brake
Bleeding machine
Wrong fitment sequence for
brake adjustments
TMC Vacuum leakage
Inadequate SOPKey point miss in
SOP
NVA movements
Brake stud
position wrong
Brake bleeding
pressure not achieved
Vacuuming pressure not
maintained
TMC brkt hole offset
Operator skill
New operator at stage
Incomplete fitment of previous
operation
Operator stress condition
Wrong Bundy tube assembled
TMC flange face to shackle
hole center dimensional
variation
Brake fluid level less
Motor HP is insufficient
Brake fluid less viscous
TMC inside passage hole miss
Wheel brake cylinder rubber cut
Bundy tube inside passage block
Less torque applied
Torque wrench end worn out
T-joint wrong thread
assembled

18. 18
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
Probable Causes: (Based on experience & Knowledge)
6 Probable causes selected for testing out of 30 possible causes,
i.e. establishing root causes.
Identify the root causes
S. No Probable Cause
1 TMC Vacuum leakage
2 TMC Mtg brackets distance fired
3 Leak detection poor-Brake bleeding machine
4 Wrong fitment sequence for brake adjustments
5 TMC flange face to shackle hole center dimensional variation
6 Brake bleeding pressure not achieved

19. 19
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5.2 Confirm the probable cause:
5. Analysis
No Probable
Cause
Testing
method
Observations Conclusion
1
TMC Vacuum
leakage
Visually
By Observing the vacuuming leak not ok parts
we found the reservoir grommet only present in
the one port and other port the grommet
missing, this clearly indicates the vacuuming not
ok.
Hypothesis
Valid

20. 20
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
2
TMC Mtg
brackets
distance
fired
Steel rule
/vernier
By comparing all the mtg brackets actual
dimensions with drawing we found there is
variation in between TMC mtg bracket and brake
pedal stud.(Total 130 vehicles inspected and
results, Out of 130 vehicles 126 vehicles out of
spec.
Hypothesis
Valid
In confirming the above cause we observed the total production and found the center
beam mounting TMC bracket to Brake pedal stud (201.3+/-0.6mm) is in out of
specification limits as resulting TMC push rod should be adjusted to Max threads as to
let Brake pedal height which will be fatal to the end customer and blocking TMC mtg
hole by disturbing the positions of primary and secondary pistons.
5.2 Confirm the probable cause:
TOP view of TMC brkt to Brake stud
201.3+/-0.6 mm

21. 21
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
 Data cross check for TMC Mtg brackets distance fired
S.N
o
Chassis No.
Brake
Pedal
Height
Pedal
height
after brake
applied
TMC mtg
brkt center
hole to
brake stud
split pin
center hole
Brake pedal
mtg stud height
from floor
TMC Adjuster
Threads(from
supplier)
Brake not
ok
Brake ok
1 Chassis No. 170 100 205 97 4 ok
2 71128 140 80 205 97 4 ok
3 71129 140 80 205 94 4 ok
4 71130 150 75 204 96 4 ok
5 71131 140 75 206 93 4 ok
6 71132 152 80 204 95 4 ok
7 71133 150 85 204 96 4 ok
8 71134 158 86 204 97 4 ok
9 71135 148 78 204 90 4 ok
10 71136 150 78 205 96 4 ok
11 71137 140 72 207 97 4 ok
12 71138 142 74 207 96 4 ok
13 71139 155 80 203 96 4 ok
14 71140 155 80 203 97 4 ok
15 71141 148 80 205 96 4 ok
16 71142 144 78 205 94 4 ok
17 71143 150 76 205 97 4 ok
18 71144 147 70 206 94 4 ok
19 71145 140 72 206 95 4 ok
20 71146 134 65 207 95 4 ok
21 71147 155 90 203 98 4 ok
22 71148 164 85 203 97 4 ok
23 71149 155 75 203 96 4 ok
24 71150 145 74 204 95 4 ok
25 71151 148 80 205 95 4 ok
26 71152 148 75 205 96 4 ok
27 71153 148 76 204 96 4 ok
28 71154 145 73 205 96 4 ok
29 71155 143 72 205 96 4 ok
30 71156 158 76 203 97 4 ok
S.N
o
Chassis No.
Brake
Pedal
Height
Pedal height
after brake
applied
TMC mtg
brkt center
hole to brake
stud split pin
center hole
Brake pedal mtg
stud height from
floor
TMC Adjuster
threads
Brake
not ok
Brake
ok
31 71158 145 74 204 94 4 ok
32 71159 153 75 204 98 4 ok
33 71160 170 90 204 99 7 ok
34 71161 140 70 205 95 4 ok
35 71163 145 72 204 95 4 ok
36 71164 154 80 204 95 4 ok
37 71165 144 70 205 94 4 ok
38 71166 165 85 201 95 4 ok
39 71167 155 85 202 97 4 ok
40 71168 155 75 204 99 4 ok
41 71169 155 78 204 97 4 ok
42 71170 146 68 205 96 4 ok
43 71171 145 75 205 96 4 ok
44 71172 152 75 204 98 4 ok
45 71173 158 70 206 96 4 ok
46 71174 146 68 204 97 4 ok
48 71176 144 68 205 98 4 ok
49 71177 145 68 204 97 4 ok
50 71178 162 75 203 96 4 ok
51 71179 152 80 206 96 4 ok
52 71180 150 75 204 95 4 ok
53 71181 145 82 204 94 4 ok
54 71182 140 68 206 94 4 ok
55 71183 142 75 205 96 4 ok
56 71184 138 72 206 95 3 ok
57 71185 164 85 203 96 2 ok
58 71186 150 78 204 95 4 ok
60 71188 151 76 203 93 4 ok
5.2 Confirm the probable cause:

22. 22
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
S.
No
Chassis
No.
Brake
Pedal
Height
Pedal height
after brake
applied
TMC mtg
brkt center
hole to
brake stud
split pin
center hole
Brake pedal
mtg stud
height from
floor
TMC Adjuster
threads
Brake
not ok
Brake
ok
61 71189 155 74 204 95 4 ok
62 71190 160 78 203 96 3 ok
63 71191 151 72 205 97 3 ok
64 71192 152 80 204 96 3 ok
65 71193 138 70 201 94 3 ok
66 71194 150 78 205 98 2 ok
67 71195 156 80 204 97 4 ok
68 71196 160 90 205 95 3 ok
69 71197 155 80 204 97 3 ok
70 71198 152 80 204 96 3 ok
71 71199 162 85 203 96 3 ok
72 71200 157 80 204 95 4 ok
73 71201 158 80 203 98 3 ok
74 71202 150 80 205 97 3 ok
75 71203 158 88 203 95 4 ok
76 71204 174 100 204 96 8 ok
77 71205 144 68 205 96 4 ok
78 71206 144 70 205 96 4 ok
79 71207 154 72 203 98 4 ok
80 71208 136 68 203 94 4 ok
81 71209 160 85 203 98 4 ok
82 71210 158 80 203 96 4 ok
83 71211 128 60 208 92 4 ok
84 71212 145 70 203 94 4 ok
85 71213 144 70 203 96 4 ok
86 71214 143 65 204 96 4 ok
87 71215 150 78 204 96 4 ok
88 71216 144 70 204 95 4 ok
89 71217 148 75 204 95 4 ok
90 71218 154 75 204 95 4 ok
S.N
o
Chassis No.
Brake
Pedal
Height
Pedal height
after brake
applied
TMC mtg
brkt center
hole to
brake stud
split pin
center hole
Brake pedal
mtg stud
height from
floor
TMC Adjuster
threads
Brake
not ok
Brake
ok
91 71219 148 70 204 95 4 ok
92 71220 162 80 203 100 4 ok
93 71221 148 80 204 96 4 ok
94 71222 158 80 204 97 4 ok
95 71223 145 78 204 96 4 ok
96 71224 157 90 203 95 4 ok
97 71225 150 70 204 96 4 ok
98 71226 160 80 203 96 4 ok
99 71227 150 80 204 98 4 ok
100 71228 154 75 204 97 4 ok
101 71229 160 80 206 95 4 ok
102 71230 144 70 205 93 4 ok
103 71231 164 80 202 96 4 ok
104 71232 165 95 202 98 4 ok
105 71233 165 90 200 97 4 ok
106 71234 150 80 204 97 4 ok
107 71235 154 80 204 96 4 ok
108 71236 132 50 208 97 4 ok
109 71237 178 107 201 99 4 ok
110 71238 165 75 204 97 4 ok
111 71239 144 70 205 97 4 ok
112 71240 159 80 204 96 4 ok
113 71241 144 75 205 95 4 ok
114 71242 155 80 204 99 4 ok
115 71243 150 80 204 96 4 ok
116 71244 144 70 204 95 6 ok
117 71245 142 70 204 96 4 ok
118 71246 142 65 205 96 4 ok
119 71247 140 70 206 97 4 ok
120 71248 154 75 204 97 4 ok
5.2 Confirm the probable cause:

23. 23
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5.2 Confirm the probable cause:
5. Analysis
1 0 3 4
0
24
52
29
0
9
3 2
0
10
20
30
40
50
60
Frequency
Distance between TMC mtg brkt and brake pedal stud
Histogram for brackets dimesions (spec: 201.3+/-0.6mm)
Mean shift
The above histogram clearly shows that
only 4 vehicles among 130 vehicles are
received as per spec (201.3+/-0.6 mm)
The above histogram clearly shows that
most of the vehicles received beyond
spec (201.3+/-0.6 mm)
 Brake pedal height before brake apply :
182+/2 mm
Distance between TMC mtg brkt to Brake
pedal stud:-201.3+/-0.6 mm
AS PER DRAWING SHOWN:
Mean as per Spec Mean deviated

24. 24
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
S.No Chassis No.
Length from
TMC mtg brkt
center hole to
brake stud split
pin center hole
Brake Pedal
Height before
brake applied
Brake Pedal
height after
brake applied
Brake pedal mtg
stud height from
floor
TMC Adjuster
threads
Brake ok
108 71236 208 132 mm 50 97 4 ok
109 71237 201 178 mm 107 99 4 ok
Variation 7 mm 46 mm 57 mm NR NR
VARIATION BEFORE BRAKE APPLIED: Due to 7mm of variation in the length from TMC bracket center hole to
brake stud pin resulted in the variation of brake pedal height of 46mm. In this case, 1 mm variation from TMC mtg
brkt center hole to brake pedal stud results in 6.57 mm of brake pedal height variation before brake applied
VARIATION AFTER BRAKE APPLIED: Due to 7mm of variation in the length from TMC bracket center hole to brake
stud pin resulted in the variation of brake pedal height of 57mm. In this case, 1 mm variation from TMC mtg brkt
center hole to brake pedal stud results in 8.14 mm of brake pedal height variation after brake applied
S.No Chassis No.
TMC mtg brkt
center hole to
brake stud split
pin center hole
Brake Pedal
Height (add
6.57
cumulative)
Pedal height after
brake applied (add
8.14 cumulative)
108 71236 208 mm 132.00 mm 50 mm
‘’ ‘’ 207 mm 138.57 mm 58.14 mm
‘’ ‘’ 206 mm 145.14 mm 66.28 mm
‘’ ‘’ 205 mm 151.71 mm 74.42 mm
‘’ ‘’ 204 mm 158.28 mm 82.56 mm
‘’ ‘’ 203 mm 164.85 mm 90.70 mm
‘’ ‘’ 202 mm 171.42 mm 98.84 mm
‘’ ‘’ 201 mm 178.00 mm 107.00 mm
5.2 Confirm the probable cause: Inference Analysis 1

25. 25
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
S. No Chassis No.
Brake Pedal
height after
brake applied
TMC mtg brkt
center hole to
brake stud split
pin center hole
Brake Pedal
Height before
brake applied
Brake pedal mtg
stud height from
floor
TMC Adjuster
threads
Brake ok
11 71138 207 140 72 97 4 Ok
51 71179 206 152 80 96 4 Ok
S.No Chassis No.
TMC mtg brkt
center hole to
brake stud
split
pin center hole
Brake Pedal
Height (add
6.57
cumulative)
Pedal height
after brake
applied (add
8.14
cumulative)
11 71138 207 mm 140.00 mm 72.00 mm
‘’ ‘’ 206 mm 146.57mm 80.14 mm
‘’ ‘’ 205 mm 153.14 mm 88.28 mm
‘’ ‘’ 204 mm 159.71 mm 96.42 mm
‘’ ‘’ 203 mm 166.28 mm 104.56 mm
‘’ ‘’ 202 mm 172.85 mm 112.70 mm
‘’ ‘’ 201 mm 179.42 mm 120.84 mm
S.No Chassis No.
TMC mtg brkt
center hole to
brake stud split
pin center hole
Brake Pedal
Height (add
6.57
cumulative)
Pedal height after
brake applied
(add 8.14
cumulative)
51 71179 206 mm 152.00 mm 80.00 mm
‘’ ‘’ 205 mm 156.57mm 88.14 mm
‘’ ‘’ 204 mm 163.14 mm 96.28 mm
‘’ ‘’ 203 mm 169.71 mm 104.42 mm
‘’ ‘’ 202 mm 176.28 mm 112.56 mm
‘’ ‘’ 201 mm 182.85 mm 120.70 mm
INFERENCE clearly justifies that if TMC Mtg bracket to
brake pedal stud received as per spec, The brake pedal
height before and after brake apply will be automatically
achieved with out adjusting TMC Push rod nut.
5.2 Confirm the probable cause:
VARIATION BEFORE BRAKE APPLIED: Due to 7mm of variation in the length from TMC bracket center hole to
brake stud pin resulted in the variation of brake pedal height of 46mm. In this case, 1 mm variation from TMC mtg
brkt center hole to brake pedal stud results in 6.57 mm of brake pedal height variation before brake applied
VARIATION AFTER BRAKE APPLIED: Due to 7mm of variation in the length from TMC bracket center hole to
brake stud pin resulted in the variation of brake pedal height of 57mm. In this case, 1 mm variation from TMC mtg
brkt center hole to brake pedal stud results in 8.14 mm of brake pedal height variation after brake applied
Inference Analysis 2

26. 26
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5.2 Confirm the probable cause:
5. Analysis
3
Leak
detection
poor
Visually/Trail
By loosening the Front flexible brake hose
slightly, We performed the bleeding operation,
at vacuuming stage operation get failed, so on
performing certain trails on the machine we
found the machine problem is not evident.
Hypothesis
Invalid
Under torque spec given to
front flexible banjo bolt
Vacuum fault detected by
the brake bleeding machine
Process fault shown on the
machine as leak detected
Process fault shown on the
machine as leak detected

27. 27
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5.2 Confirm the probable cause:
5. Analysis
No Probable
Cause
Testing
method
Observations Conclusion
4
Wrong fitment
sequence for
brake
adjustments
Visually
By observing all the sequence following in line
we found abnormality in adjusting TMC Push
rod before brake bleeding for achieving brake
pedal height (182+/-2 mm).
Hypothesis
Valid
S. No Fitment Sequence
1 13 joints torque application
2 TMC mtg to bracket
3 Applying torque to TMC
4 Placing brake pedal to stud
5 split pins fitment to brake pedal
6 Connect TMC push rod to brake pedal
7
Adjust TMC push rod threads to achieve brake
pedal height (182+/-2mm)
8 Brake bleeding through machine
9 Brake switch mtg to bracket
10 Process complete

28. 28
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
Suspecting this lock nut as disturbed before brake
bleeding &shackle moved outwards and there will be no
free play in pedal. This result in push rod moving in arrow
direction further moving of piston suspecting piston seal
May block 0.5 mm hole. (As hole will block completely the
vacuuming process by the machine will not done
completely in machine and some portion of air will left
inside TMC , as air is compressible and Brake fluid is
incompressible, suspecting brake not ok
0.5mm
Dia hole
Seal
For testing the above observations we decided to take a trail, process
change as first brake bleeding through machine with out adjusting the
TMC mtg nut and after Brake Bleeding adjust the TMC nut to fulfill the
requirements of brake pedal height (182+/-2mm)
Sectional view of TMC

29. 29
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
 Conducted trial on 2 days full production (280 vehicles) by setting brake pedal height 182+/- 2 mm after brake bleeding in and found zero
occurrence of brake bleeding related issues hence hypothesis valid.
S.No
Chassis
No.
TMC Adjuster
Threads(from
supplier)
Brake not
ok
Brake ok
1 71128 4 ok
2 71129 4 ok
3 71130 4 ok
4 71131 4 ok
5 71132 4 ok
6 71133 4 ok
7 71134 4 ok
8 71135 4 ok
9 71136 4 ok
10 71137 4 ok
11 71138 4 ok
12 71139 4 ok
13 71140 4 ok
14 71141 4 ok
15 71142 4 ok
16 71143 4 ok
17 71144 4 ok
18 71145 4 ok
19 71146 4 ok
20 71147 4 ok
21 71148 4 ok
22 71149 4 ok
23 71150 4 ok
24 71151 4 ok
25 71152 4 ok
26 71153 4 ok
27 71154 4 ok
28 71155 4 ok
29 71156 4 ok
30 71157 4 ok
S.No
Chassis
No.
TMC Adjuster
Threads(from
supplier)
Brake not
ok
Brake ok
31 71158 4 ok
32 71159 4 ok
33 71160 7 ok
34 71161 4 ok
35 71163 4 ok
36 71164 4 ok
37 71165 4 ok
38 71166 4 ok
39 71167 4 ok
40 71168 4 ok
41 71169 4 ok
42 71170 4 ok
43 71171 4 ok
44 71172 4 ok
45 71173 4 ok
46 71174 4 ok
48 71176 4 ok
49 71177 4 ok
50 71178 4 ok
51 71179 4 ok
52 71180 4 ok
53 71181 4 ok
54 71182 4 ok
55 71183 4 ok
56 71184 3 ok
57 71185 2 ok
58 71186 4 ok
60 71188 4 ok
5.2 Confirm the probable cause:
S.No
Chassis
No.
TMC Adjuster
Threads(from
supplier)
Brake
not ok
Brake
ok
61 71189 4 ok
62 71190 3 ok
63 71191 3 ok
64 71192 3 ok
65 71193 3 ok
66 71194 2 ok
67 71195 4 ok
68 71196 3 ok
69 71197 3 ok
70 71198 3 ok
71 71199 3 ok
72 71200 4 ok
73 71201 3 ok
74 71202 3 ok
75 71203 4 ok
76 71204 8 ok
77 71205 4 ok
78 71206 4 ok
79 71207 4 ok
80 71208 4 ok
81 71209 4 ok
82 71210 4 ok
83 71211 4 ok
84 71212 4 ok
85 71213 4 ok
86 71214 4 ok
87 71215 4 ok
88 71216 4 ok
89 71217 4 ok
90 71218 4 ok
S.No
Chassis
No.
TMC Adjuster
Threads(from
supplier)
Brake
not ok
Brake
ok
91 71219 4 ok
92 71220 4 ok
93 71221 4 ok
94 71222 4 ok
95 71223 4 ok
96 71224 4 ok
97 71225 4 ok
98 71226 4 ok
99 71227 4 ok
100 71228 4 ok
101 71229 4 ok
102 71230 4 ok
103 71231 4 ok
104 71232 4 ok
105 71233 4 ok
106 71234 4 ok
107 71235 4 ok
108 71236 4 ok
109 71237 4 ok
110 71238 4 ok
111 71239 4 ok
112 71240 4 ok
113 71241 4 ok
114 71242 4 ok
115 71243 4 ok
116 71244 6 ok
117 71245 4 ok
118 71246 4 ok
119 71247 4 ok
120 71248 4 ok

30. 30
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5.2 Confirm the probable cause:
5. Analysis
5
TMC flange face to
shackle hole center
dimensional
variation
Vernier
We have cross verified 50 Tandem master
cylinders and found the dimension between the
TMC flange face to Shackle hole center is with
in specification the tolerance range is (220 +/-
1.0 mm)
Hypothesis
Invalid

31. 31
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5.2 Confirm the probable cause:
5. Analysis
6
Brake
bleeding
pressure not
achieved
Visually/Trail
In confirm the probable cause we have taken
the Filling pressure readings of the brake
bleeding machine and observed that the all the
readings(not fall below the set value) (Set
value: 3.5 Bar)
Hypothesis
Invalid

32. 32
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
5. Analysis
Following are the Probable causes identified for Brake bleeding related issues
5.2 Confirm the probable cause:
S. No Probable Cause
1 TMC Vacuum leakage
2 TMC Mtg brackets distance fired
3 Wrong fitment sequence for brake adjustments

33. 33
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
WHY - WHY Analysis
5.3 Identify the root causes:
S. No EFFECT WHY WHY
ACTION
1 TMC Vacuum leakage
Grommet missing inside the
secondary port not been
identified during reservoir test
Wrong air connections are
made to impact type
punching cylinder and
leakage inside impact type
punching cylinder
TO REPLACE IMPACT TYPE
PUNCHING CYLINDER TO
REGULAR DOUBLE ACTING
CYLINDER TO AVOID
OPERATING DURING
TESTING CYCLE
2
TMC Mtg brackets
distance fired
Distance variation is due to
fixture and gauge were not in
good condition
No fixture and gauge
monthly calibration and
maintenance
ICA: TMC MTG BRKT TO
BRAKE PEDAL STUD
DISTANCE TO BE
CORRECTED AS PER
DRAWING
PCA: MONTHLY
CALIBRATIONS FOR ALL
FIXTURES AND GAUGES
INITIATED AT SUPPLIER
END
3
Wrong fitment
sequence for brake
adjustments
Inadequate SOP for pedal
height (182+/- 2mm)
adjustment.
Improper process defined
when the brake pedal height
requirement raised by PVT
PROPER PROCESS
DEFINITION THAT BRAKE
PEDAL ADJUSTMENT TO BE
DONE AFTER BRAKE
BLEEDING PROCESS

34. 34
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures
6.1 Actions Decided
Root Cause Action Plan Target Dt Resp. Status
TMC Vacuum
leakage
To replace impact type
punching cylinder with regular
double acting cylinder to avoid
operating during testing cycle.
10.08.2012 VGS Prasad CLOSED
TMC Mtg brackets
distance fired
ICA: TMC mounting brkt to rake
stud distance to be corrected as
per drawing
PCA: Monthly calibration of all
gauges and fixtures initiated at
supplier end.
25.12.2013
BHANU
PRAKASH
CLOSED
Wrong fitment
sequence for brake
adjustments
Brake bleeding process to be
changed, first brake bleeding
through machine and next
adjustment of TMC push rod nut
to achieve brake pedal height
(182 +/- 2mm)
25.12.2013
K VAMSI CLOSED

35. 35
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures
Root Cause Action Plan Target Dt Resp. Status
TMC Vacuum
leakage
To replace impact type punching
cylinder with regular double acting
cylinder to avoid operating during
testing cycle.
10.08.2012 VGS Prasad CLOSED

36. 36
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures

37. 37
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures

38. 38
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures

39. 39
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures

40. 40
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures

41. 41
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures

42. 42
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures
Impact type punching cylinder is replaced with regular double acting
cylinder to avoid operating during testing cycle.

43. 43
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures
Root Cause Action Plan Target Dt Resp. Status
TMC Mtg
brackets
distance fired
ICA: TMC mounting brkt to rake stud
distance to be corrected as per
drawing
PCA: Monthly calibration of all
gauges and fixtures initiated at supplier
end.
25.12.2012 Bhanu Prakash CLOSED
The brake pedal stud mtg fixture and TMC mtg bracket fixtures are
corrected as per the required dimensions (202 mm Max dimension) and
fixture condition is monitored every 15 days at the supplier end frequently
and separate fixture audit will be done accordingly with plan
Brake stud and brake
switch bracket combined
fixture(modified)

44. 44
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
6. Implement the corrective measures
Root Cause Action Plan Target Dt Resp. Status
Wrong fitment
sequence for
brake
adjustments
Brake bleeding process to be changed,
first brake bleeding through machine and
next adjustment of TMC push rod nut to
achieve brake pedal height (182 +/-
2mm)
25.12.2012 K vamsi CLOSED
S.no BEFORE AFTER (To be modified)
1 13 joints torque application 13 joints torque application
2 TMC mtg to bracket TMC mtg to bracket
3 Applying torque to TMC Applying torque to TMC
4 Placing brake pedal to stud Placing brake pedal to stud
5 split pins fitment to brake pedal split pins fitment to brake pedal
6 Connect TMC push rod to brake pedal Connect TMC push rod to brake pedal
7
Adjust TMC push rod threads to achieve
brake pedal height (182+/-2mm)
Brake bleeding through machine with out
adjusting TMC push rod
8 Brake bleeding through machine
Adjust TMC push rod threads to achieve
brake pedal height (182+/-2mm)
9 Brake switch mtg to bracket Brake switch mtg to bracket
10 Process complete Process complete
Sequence
number 7 & 8
interchanged

45. 45
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
7. Check & confirm the results & effects
7.1 Verify Results:
238 217
255 234 221 210 225 201 195 190 203 186
0 0 0
0
50
100
150
200
250
300
Brake Bleeding related issues(occurrence/ Month)
PCA 1 PCA 2
Root Cause Action Plan Target Dt Resp. Status
TMC Vacuum leakage
To replace impact type punching cylinder
with regular double acting cylinder to avoid
operating during testing cycle.
10.08.2012 VGS Prasad CLOSED
TMC Mtg brackets distance
fired
Play should be arrested to free release to
cover the 2mm clearance of brake pedal
shaft and center beam brkt hole
25.12.2013 BHANU PRAKASH CLOSED
Wrong fitment sequence
for brake adjustments
Brake bleeding process to be changed, first
brake bleeding through machine and next
adjustment of TMC push rod nut to achieve
brake pedal height (182 +/- 2mm)
25.12.2013 K VAMSI CLOSED
7.2 Full Scale Implementation plan:

46. 46
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
7.3 Tangible Benefits
7.3 Intangible Benefits
Effective functioning of brakes
Morale of the operator is increased.
Customer satisfaction increases
7. Check & confirm the results & effects
1. Elimination of V1+ Concern
2. Improvement in quality indicators (FRC, FBO & DPV)
3. Rework cost saved (Avg 230veh/month-Rs. 96,600/- per year)
4.Rework at hold eliminated.
5. Brake efficiency increases.
6. Elimination of manual brake bleeding
7. Customer quality increases
8. Improved Delivery performance in PDI

47. 47
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
8. Standardisation
8.1 Updation of documents:
8.2 Training:
8.3 Additional Audit / Check
Concerned operators are given OPL’s and made familiar with the concept
regarding its function, operation
Process modification added in Process Audits
DCP documents PFC,PFMEA, CP & SOP updated
(PSW Ref no: ALFA/ASSY/PCRN/F’13/13)
PCRN (PCRN No: ALFA-F13-13)
Concern closure report (ZCB3Q46212)
Process sheets updated.

48. 48
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
9. Summarise & Plan future actions
9.2 Horizontal Deployment:
Horizontal deployment can be applied for all 3-wheeler model manufacturers.
Information shared with HARIDWAR also.
9.3 Lessons Learnt:
9.1 Conclusion:
By doing the several analysis, concluding the results from analysis the process
change and the bracket correction from supplier eliminated the long pending,
Top FBO effected concern brake bleeding related issues completely thrown
out.
TGR: By process change in brake bleeding process and brkt correction at
supplier end ,issue thrown out completely.
TGW: After Process change we felt that due to pressure of brake fluid the brake
shoe liners and padding may subjected to severe temperature changes and we
checked the temperature and found ok (No color fading observed to the Brake
shoe liners).

49. 49
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
QC STORY PLAN
SR ACTIVITY
JUL'12 AUG'12 SEP'12 OCT'12 NOV'12 DEC'12
W1 W2 W3 W4 W1 W2 W3 W4 W1 W2 W3 W4 W1 W2 W3 W4 W1 W2 W3 W4W1 W2 W3 W4
1 Problem selection
2 Setting Goal
3
Data collection to understand
current situation
4 Analysis of cause
5
Validation and verification of
possible cause for brake
bleeding related issues
6
Validation and verification of
possible cause for brake
bleeding process
7
Counter measure of potential
root causes
8 Standardization of action
9
Conclusion (Sum-up &
Presentation)
PLAN
COMPLETE

50. 50
AUTOMOTIVE SECTOR
Mahindra Quality System (A. S.)
Thank You