Mitsubishi Montero Sport (2004+). Manual - part 770

BASIC BRAKE SYSTEM DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-5

INSPECTION PROCEDURE 2: Insufficient Braking Power

.

DIAGNOSIS

STEP 1. Check whether the brake fluid is low, is the correct 
fluid (A/T fluid, engine oil, etc.) or is contaminated (debris, 
sand, etc.).
Q: Is there fault?

YES : Refill or replace with the specified brake fluid DOT 3 

or DOT 4. Bleed the brakes if necessary (Refer to 

P.35A-19

). Then go to Step 9. 

NO :  Go to Step 2. 

STEP 2. Check for spongy (not firm brakes).
(1) With engine not running, depress the brake pedal rapidly 

several times to deplete booster vacuum reserve.

(2) With the brake pedal fully released, depress the brake 

pedal slowly until it stops.

(3) With a measuring stick (ruler, etc.) next to the brake pedal, 

depress the pedal firmly and measure the distance the 
pedal traveled.

Q: Is the distance greater than 20 mm (0.8 inch)?

YES : Bleed the brakes to remove air in the fluid. (Refer to 

P.35A-19

.) Then go to Step 9.

NO :  Go to Step 3. 

STEP 3. Check the lining and brake drum contact.

Put chalk on the inner surface of the brake drum. Rub the lining 
against the drum inner surface.
NOTE: Clean off chalk after check.
Q: Does the lining wipe off or smudge the chalk across the 

full width of the lining?
YES : Go to Step 4.
NO :  Replace the shoe and lining assemblies on both 

sides. Go to Step 9.

STEP 4. Check the auto adjuster function. 

Refer to 

P.35A-25

.

Q: Is there fault?

YES : Repair it. Then go to Step 9.
NO :  Go to Step 5.

STEP 5. Check the brake booster function.

Refer to 

P.35A-17

.

Q: Is there fault?

YES : Replace the part. Then go to Step 9.
NO :  Go to Step 6.

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BASIC BRAKE SYSTEM DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-6

STEP 6. Check for pinched or restricted brake tube or 
hose.
Q: Is there pinched or restricted brake tube or hose?

YES : Replace that complete section of brake tube or brake 

hose. Then go to Step 9.

NO :  Go to Step 7.

STEP 7. Check for oil, water, etc., on the pad or lining 
contact surfaces of all brakes.
Q: Is oil, water, etc., on the pad or lining contact surface?

YES : Replace the part and determine and repair 

source/cause of foreign material. Recheck symptom. 
Then go to Step 9.

NO :  Diagnosis is complete. If condition persists, go to Step 

8.

STEP 8. Check the proportioning valve operation. 
<Vehicles without ABS>

Refer to 

P.35A-18

.

Q: Is there fault?

YES : Replace the part. Then go to Step 9.
NO :  Go to Step 9.

STEP 9. Retest the system.
Q: Is the symptom eliminated?

YES : The procedure is complete.
NO :  Start over at Step 1. If a new symptom surfaces, refer 

to the symptom chart 

P.35A-3

.

INSPECTION PROCEDURE 3: Increased Pedal Stroke (Reduced Pedal-to-Floor Board Clearance)

.

DIAGNOSIS

STEP 1. Check for spongy (not firm brakes).
(1) With engine not running, depress the brake pedal 

rapidly several times to deplete booster vacuum 
reserve.

(2) With the brake pedal fully released, depress the 

brake pedal slowly until it stops.

(3) With a measuring stick (ruler, etc.) next to the 

brake pedal, depress the pedal firmly and 
measure the distance the pedal traveled.

Q: Is the distance greater than 20 mm (0.8 inch)?

YES : 

Bleed the brakes to remove air in the fluid. 

Refer to 

P.35A-19

. Then go to Step 8.

NO : 

Go to Step 2.

STEP 2. Check the pad or lining for wear.

Refer to 

P.35A-23

 or 

P.35A-24

.

Q: Is the pad or lining thickness outside of 

specifications?

YES : 

Replace the part. Then go to Step 8.

NO : 

Go to Step 3.

STEP 3. Check the vacuum hose and check valve 
for damage.

Refer to 

P.35A-18

.

Q: Is there damage?

YES : 

Replace the part. Then go to Step 8.

NO : 

Go to Step 4.

BASIC BRAKE SYSTEM DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-7

STEP 4. Check the master cylinder function.

Refer to 

P.35A-26

.

Q: Is there fault?

YES : 

Repair it. Then go to Step 8.

NO : 

Go to Step 5.

STEP 5. Check for brake fluid leaks.

Q: Is there leaks?

YES : 

Check the connection for looseness, 

corrosion, etc. Clean and repair as 
necessary. If leaking in any tube or hose 
section, replace the complete tube or hose. 
Then go to Step 8  .

NO : 

Go to Step 6.

STEP 6. Check the auto adjuster function. 

Q: Is there fault?

YES : 

Repair the part. Then go to Step 8.

NO : 

Go to Step 7.

STEP 7. Check the clearance (too much) between 
the pushrod and primary piston.

Refer to 

P.35A-28

.

Q: Is the clearance outside of specifications?

YES : 

Adjust the clearance. Then go to Step 8.

NO : 

Go to Step 8.

STEP 8. Retest the system.

Q: Is the symptom eliminated?

YES : 

The procedure is complete.

NO : 

Start over at Step 1. If a new symptom 
surfaces, refer to the symptom chart 

P.35A-3

.

INSPECTION PROCEDURE 4: Brake Drag

.

DIAGNOSIS

STEP 1. Check the parking brake lever return.

Q: Is there fault?

YES : Repair it. Then go to Step 9.
NO :  Go to Step 2.

STEP 2. Check the parking brake pull amount.

Refer to GROUP 36, On-vehicle Service 

− Parking Brake Lever 

Stroke Check and Adjustment 

P.36-2

.

Q: Is there fault?

YES : Adjust it. Then go to Step 9.
NO :  Go to Step 3.

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PARKING
BRAKE
LEVER

BASIC BRAKE SYSTEM DIAGNOSIS

TSB Revision

BASIC BRAKE SYSTEM

35A-8

STEP 3. Check the brake pedal return spring for 
deterioration.

Q: Is there deterioration?

YES : Replace the spring. Then go to Step 9.
NO :  Go to Step 4.

STEP 4. Check the rear brake shoe springs for breakage.

Refer to 

P.35A-37

.

Q: Are the brake shoe springs broken?

YES : Replace the spring. Then go to Step 9.
NO :  Go to Step 5.

STEP 5. Check the amount of grease at each sliding 
section.

Refer to 

P.35A-37

.

Q: Is the grease amount low?

YES : Apply grease. Then go to Step 9.
NO :  Go to Step 6.

STEP 6. Check the clearance (too low) between the 
pushrod and primary piston.

Refer to 

P.35A-28

.

Q: Is there fault?

YES : Adjust the clearance. Then go to Step 9.
NO :  Go to Step 7.

STEP 7. Check the master cylinder piston return spring for 
damage and return port for clogging.

Refer to 

P.35A-30

.

Q: Is there damage?

YES : Replace the part. Then go to Step 9.
NO :  Go to Step 8.

STEP 8. Check port for clogging.
Q: Is the port clogged?

YES : Repair it. Then go to Step 9.
NO :  Go to Step 9.

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RETURN SPRING

PEDAL SUPPORT
MEMBER