Mitsubishi 380. Manual — part 295

ON-VEHICLE SERVICE

BASIC BRAKE SYSTEM

35A-14

BRAKE PEDAL FREE PLAY

1. Turn the ignition switch to the "LOCK" (OFF) position, and

depress the brake pedal two or three times. After eliminating
the vacuum in the brake booster, press the pedal down by
hand, and confirm that the amount of movement before
resistance is met (free play) is within the standard value
range.

Standard value: 3

− 8 mm (0.12 − 0.31 inch)

2. If the brake pedal play is not within the standard value,

check the following, and adjust or replace if necessary:

• Excessive play between the brake pedal and the clevis pin,

or between the clevis pin and the brake booster operating
rod

• Brake pedal height

• Installation position of the stop light switch, etc.

CLEARANCE BETWEEN BRAKE PEDAL AND
DASH PANEL

1. Turn up the carpet, etc. under the brake pedal.
2. Start the engine, depress the brake pedal with

approximately 500 N (112 pounds) of force, and measure
the clearance between the brake pedal and the dash panel.

Standard value: 110 mm (4.33 inches) or more [From
the surface of dash panel to the face of pedal pad]

3. If the clearance is outside the standard value, check for air

trapped in the brake line and check the thickness of the disc
brake pad. Andjust and replace defective parts as required.

4. Return the carpet etc. to its original position.

BRAKE BOOSTER OPERATING TEST

M1351001000372

1. For simple checking of the brake booster operation, carry

out the following tests:

(1) Run the engine for one or two minutes, and then stop it. If

the pedal depresses fully the first time but gradually
becomes higher when depressed succeeding times, the
booster is operating properly. If the pedal height remains
unchanged, the booster is defective. Go to step 2.

AC206445

AB

AC206446

AB

AC000870

GOOD

NO GOOD

AB

ON-VEHICLE SERVICE

BASIC BRAKE SYSTEM

35A-15

(2) With the engine stopped, step on the brake pedal several

times. Then step on the brake pedal and start the engine.
If the pedal moves downward slightly, the booster is in
good condition. If there is no change, the booster is
defective. Go to step 3.

(3) With the engine running, step on the brake pedal and

then stop the engine. Hold the pedal depressed for 30
seconds. If the pedal height does not change, the booster
is in good condition, if the pedal rises, the booster is
defective.

2. If the above three tests are okay, the booster is OK. If one of

the above three tests is not okay, the check valve, vacuum
hose, or booster is defective. Check the check valve (Refer
to

P.35A-15

), vacuum hose for leaks, high volume engine

vacuum applied to booster. Repair or replace as necessary.
If these are OK, replace booster and repeat this test starting
at Step 1.

CHECK VALVE OPERATION CHECK

M1351009000376

CAUTION

The check valve should not be removed from the vacuum
hose.
1. Remove the vacuum hose. (Refer to

P.35A-26

).

CAUTION

If the check valve is defective, replace it as an assembly
together with the vacuum hose.
2. Check the operation of the check valve by using a vacuum

pump.

AC000871AB

WHEN ENGINE

IS STOPPED

WHEN ENGINE

IS STARTED

AC000872

GOOD

NO GOOD

AB

VACUUM PUMP
CONNECTION

CRITERIA

Connection at the brake
booster side (A)

A negative pressure
(vacuum) is created and
held.

Connection at the intake
manifold side (B)

A negative pressure
(vacuum) is not created.

AC000873AB

A

B

VALVE

SPRING

INTAKE

MANIFOLD

SIDE

(DOES NOT

HOLD)

BOOST-

ER SIDE

(HOLDS)

ON-VEHICLE SERVICE

BASIC BRAKE SYSTEM

35A-16

BLEEDING

M1351001400455

CAUTION

Use only brake fluid DOT 3 or DOT 4. Never mix the speci-
fied brake fluid with other fluid as it will influence the brak-
ing performance significantly.

.

MASTER CYLINDER BLEEDING

The master cylinder used has no check valve, so if bleeding is
carried out by the following procedure, bleeding of air from the
brake pipeline will become easier. (When brake fluid is not con-
tained in the master cylinder).
1. Fill the reserve tank with brake fluid.

2. Keep the brake pedal depressed.
3. Have another person cover the master cylinder outlet with a

finger.

4. With the outlet still closed, release the brake pedal.

5. Repeat steps 2

− 4 three or four times to fill the inside of the

master cylinder with brake fluid.

.

BRAKE LINE BLEEDING

Start the engine and bleed the air in the sequence shown in the
figure.

15DB172A

OUTLET

15DB173A

4

2

1

3

VEHICLES WITH ABS

ON-VEHICLE SERVICE

BASIC BRAKE SYSTEM

35A-17

BRAKE FLUID LEVEL SENSOR CHECK

M1351009100403

The brake fluid level sensor is in good condition if there is no
continuity when the float surface is above "MIN" and if there is
continuity when the float surface is below "MIN".

DISC BRAKE PAD CHECK AND REPLACEMENT

M1351002300398

NOTE: Uneven wearor tapering of brake pad may be caused
by either caliper piston not operating correctly .

CAUTION

• Whenever a pad must be replaced, replace both LH and

RH wheel pads as a set to prevent the vehicle from pull-
ing to one side when braking.

• If there is a significant difference in the thicknesses of

the pads on the left and right sides, check the sliding
condition of the piston and slide pins.

1. Check the brake pad thickness through the caliper body

check port.(Rear). Front pad check can be viewed from rotor
side.

Standard value: 10.0 mm (0.39 inch)
Minimum limit: 2.0 mm (0.08 inch)

15DB186A

15DB191A

WHEN NEW

WHEN WORN

PAD

BRAKE

DISC

15DB179A

<REAR>

15DB192A

<FRONT>