Mitsubishi 380. Manual - part 298

MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER

BASIC BRAKE SYSTEM

35A-26

MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER

REMOVAL AND INSTALLATION

M1351003700407

Required Special Tool:

• MB991568: Push Rod Adjusting Socket

Pre-removal Operation
• Strut Tower Bar Removal (Refer to GROUP 42, Strut 

Tower Bar 

P.42-12

).

• Battery Removal
• Brake Fluid Draining

Post-installation Operation
• Brake Fluid Supplying and Air Bleeding (Refer to 

P.35A-16

).

• Brake Pedal Adjustment (Refer to 

P.35A-13

).

• Battery Installation

• Strut Tower Bar Installation (Refer to GROUP 42, Strut 

Tower Bar 

P.42-12

).

15DB174A

25 ± 2 N·m

18 ± 2 ft-lb

6

1

2

7

11

15 ± 2 N·m

12 ± 1 ft-lb

2

9

10

14 ± 2 N·m

122 ± 25 in-lb

14

12

13

15

16

8

N

15 ± 2 N·m

12 ± 1 ft-lb

BRAKE MASTER CYLINDER 
ASSEMBLY REMOVAL STEPS

1.

BRAKE FLUID LEVEL INDICATOR 
SWITCH CONNECTOR

2.

BRAKE TUBE CONNECTION

5.

BRAKE MASTER CYLINDER 
ASSEMBLY

6.

SPRING PIN

7.

BRAKE FLUID RESERVOIR 
ASSEMBLY

8.

MASTER CYLINDER FLUID 
RESERVOIR SEAL

9.

BRAKE FLUID LEVEL INDICATOR 
SWITCH

10. BRAKE FLUID RESERVOIR CAP

BRAKE BOOSTER VACUUM 
HOSE REMOVAL STEP

>>A<<

11. BRAKE BOOSTER VACUUM 

HOSE 

BRAKE BOOSTER ASSEMBLY 
REMOVAL STEPS

1.

BRAKE FLUID LEVEL INDICATOR 
SWITCH CONNECTOR

2.

BRAKE TUBE CONNECTION

5.

BRAKE MASTER CYLINDER 
ASSEMBLY

>>B<<

•

PUSH ROD PROTRUSION 
AMOUNT CHECK AND 
ADJUSTMENT

>>A<<

11. BRAKE BOOSTER VACUUM 

HOSE

12. BRAKE BOOSTER PIN
13. BRAKE BOOSTER PIN 

ASSEMBLY

14. BRAKE BOOSTER NUT
15. BRAKE BOOSTER ASSEMBLY
16. BRAKE BOOSTER BODY SEAL

MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER

BASIC BRAKE SYSTEM

35A-27

INSTALLATION SERVICE POINTS

.

>>A<< BRAKE BOOSTER VACUUM HOSE 
CONNECTION

Insert vacuum hose with its paint mark facing upward.

.

>>B<< PUSH ROD PROTRUSION AMOUNT 
CHECK AND ADJUSTMENT

1. Use the vacuum pump to measure dimension "A" applying a 

negative pressure of 66.7 kPa (19.7 inHg) to the brake 
booster. 

Standard value (A): 5.0 mm 

± 0.1

15DB175A

VACUUM HOSE

WHITE PAINT MARK

YELLOW PAINT MARK

15DB185A

A

MEASURING DISTANCE A

BLOCK GAUGE

MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER

BASIC BRAKE SYSTEM

35A-28

2. If the protrusion amount is not within the standard value 

range, adjust the push rod length by turning the push rod. 
Use special tool MB991568 to turn the push rod while 
holding the rod spline with angle-nose pliers.

MASTER CYLINDER

M1351004200375

DISASSEMBLY AND ASSEMBLY

AC210714 AB

MB991568

ANGLE-NOSE PLIERS

ROD SPLINE

15DB194A

3

5

6

4

N

N

N

6

5

MASTER CYLINDER KIT

BRAKE FLUID: DOT 3 OR DOT 4

4

1

5

4

2

N

DISASSEMBLY STEPS    

1. BRAKE MASTER CYLINDER TO 

FLUID RESERVOIR SEAL

2. BRAKE MASTER CYLINDER PIN 

<VEHICLES WITH ABS>

<<A>>

3. BRAKE MASTER CYLINDER UNION 

RETAINER

4. PRIMARY PISTON ASSEMBLY
5. SECONDARY PISTON ASSEMBLY
6. MASTER CYLINDER BODY

DISASSEMBLY STEPS     

MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER

BASIC BRAKE SYSTEM

35A-29

DISASSEMBLY SERVICE POINT

.

<<A>> BRAKE MASTER CYLINDER UNION 
RETAINER DISASSEMBLY

Remove the brake master cylinder union retainer while 
depressing the piston.

INSPECTION

M1351004300297

• Check the inner surface of master cylinder body for rust or 

pitting.

• Check the primary and secondary pistons for rust, scoring, 

wear or damage.

AC000903