Mitsubishi Montero (2002-2004). Manual - part 1027

HYDRAULIC BRAKE BOOSTER (HBB)

TSB Revision

BASIC BRAKE SYSTEM

35A-133

HYDRAULIC BRAKE BOOSTER (HBB)

REMOVAL AND INSTALLATION

M1351010700056

CAUTION

To prevent damaging the HBB pump motor, do not turn the ignition switch to the "ON" position until 
installation is completed and brake fluid is replenished.

Pre-removal Operation
• Bleeding of the brake fluid power supply system (Depress 

the brake pedal repeatedly more than 40 times with the 

ignition switch at the LOCK (OFF) position.)

• Brake Fluid Draining

Post-installation Operation
• Brake Pedal Adjustment (Refer to 

P.35A-115

.)

• Brake Fluid Supplying

• Brake Line Bleeding (Refer to 

P.35A-122

.)

• HBB Operating Check (Refer to 

P.35A-117

.)

ACX00672 AB

2

2

6

4

3

7

7

8

5

1

14 ± 3 N

·

m

124 ± 26 in-lb

15 ± 2 N

·

m

11 ± 2 ft-lb

N

N

REMOVAL STEPS

•

BATTERY

1.

HARNESS CONNECTORS

2.

BRAKE TUBE CONNECTION

3.

SNAP PIN

4.

CLEVIS PIN

5.

HBB MOUNTING NUT

<<A>> >>A<<

6.

HBB

7.

SEAL

8.

SPACER

REMOVAL STEPS (Continued)

HYDRAULIC BRAKE BOOSTER (HBB)

TSB Revision

BASIC BRAKE SYSTEM

35A-134

REMOVAL SEVICE POINT

.

<<A>> HBB REMOVAL

CAUTION

Since high-pressure is applied to the tube shown in the 
illustration, do not bend it.

INSTALLATION SEVICE POINT

.

>>A<< HBB INSTALLATION

CAUTION

Since high-pressure is applied to the tube shown in the 
illustration, do not bend it.

ACCUMULATOR REPLACEMENT

M1351015800014

Required Special Tool:

• MB991926: Accumulator Wrench

1. Depress the brake pedal repeatedly more than 40 times until 

the pedal depressing force feels heavy with the ignition 
switch at the "LOCK" (OFF) position to release the pressure 
of the HBB power supply system.

CAUTION

To prevent damaging the pump motor, do not turn the igni-
tion switch to the "ON" position until brake fluid is replen-
ished.
2. Drain the brake fluid.

AC204332

AC204332

HYDRAULIC BRAKE BOOSTER (HBB)

TSB Revision

BASIC BRAKE SYSTEM

35A-135

3. Using special tool MB991926, remove the accumulator.
4. Remove the o-ring installed between the accumulator and 

the HBB.

5. Install a new o-ring to a new accumulator.
6. Using special tool MB991926, install the new accumulator to 

the HBB. The tightening torque of the accumulator is 54 

± 5 

N

⋅m (40 ± 4 ft-lb).

7. Fill the HBB brake system with brake fluid and bleed the 

HBB brake system (Refer to 

P.35A-122

).

8. Carry out the function and operation check of power supply 

system (Refer to 

P.35A-117

).

9. Erase HBB diagnostic trouble code (Refer to 

P.35A-14

).

10.Dispose of the removed accumulator (Refer to 

P.35A-135

).

ACCUMULATOR DISPOSAL

M1351015900011

WARNING

Do not disassemble, throw into fire, cut, weld, drop, 
or shock the accumulator without purging filled gas.

1. Fix the accumulator on a vice as illustrated.

2. Punch in the area shown in the illustration to fix the drilling 

position.

3. Set a drill [diameter 

φ 4 mm (φ 0.16 in)] on the drill motor.

AC204060

AB

MB991926

ACCUMULATOR

AC204540

AC204541AB

Φ

50 mm

Φ

2.0 in

HYDRAULIC BRAKE BOOSTER (HBB)

TSB Revision

BASIC BRAKE SYSTEM

35A-136

WARNING

Wear protective glasses during drilling to protect you 
from scattered chips caused by spouting gas.

4. Using a drill motor, drill a hole on the accumulator to purge 

filled gas.
NOTE: 

.

•

There is no danger of accumulator burst due to drilling 
work.

•

You can hear purging sound of gas as soon as a hole is 
made on the accumulator.

•

The filled gas is nitrogen, which is colorless, odorless 
and harmless.

5. Dispose of the accumulator in compliance with Federal, 

state, and local laws.

DISASSEMBLY AND ASSEMBLY

M1351010800064

AC204539

AC204377 AC

1

2

1.7 ± 0.3 N

•

m

15 ± 2.6 in-lb

25.5 ± 5.1 N

•

m

19 ± 3 ft-lb

19

21

20

22

23

3

4

BRAKE FLUID: DOT3 OR DOT4

24

5

6

7

8

9

15

15.2 ± 3 N

•

m

11 ± 2 ft-lb

3.0 ± 0.5 N

•

m

26 ± 4 in-lb

1.7 ± 0.1 N

•

m

15 ± 1 in-lb

14

13

12

11

18

17

16

10

7.8 ± 1.5 N

•

m

69 ± 13 in-lb

7.8 ± 1.5 N

•

m

69 ± 13 in-lb

1.7 ± 0.3 N

•

m

15 ± 2.6 in-lb

54 ± 5 N

•

m

40 ± 4 ft-lb

N

N

N

N

11.8 ± 2.3 N

•

m

104 ± 20 in-lb