Mitsubishi Montero (2002-2004). Manual — part 1023

ON-VEHICLE SERVICE

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BASIC BRAKE SYSTEM

35A-117

HBB OPERATING CHECK

M1351010400055

CAUTION

If the diagnostic trouble code is stored in the M-ASTC-ECU
memory, erase it after diagnosis is completed.

Function and Operation Check of Power Supply
System

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 HBB power supply system.

2. Check that the fluid level in the reservoir is at the "MAX" line.
3. Chock the wheels and release the parking brake.
4. Turn the ignition switch to the "ON" position and measure

how long it takes for the pump motor to start, then stop.

Standard value: 20

− 80 seconds

5. After the pump motor stops, start the engine to confirm that

the brake warning light does not come on.

6. Stop the engine and turn the ignition switch to the "ON"

position again.

7. Confirm that the pump motor operates, then stops when the

brake pedal is depressed repeatedly 4 to 5 times.

8. Depress the brake pedal repeatedly 4 to 5 times again to

measure how long it takes for the pump motor to start, then
stop.

Standard value: 2

− 11 seconds

9. Check and confirm the following items 120 seconds or more

after turning ON the ignition switch.

CAUTION

Check and confirm the following items 120 seconds or
more after turning the ignition switch to the "ON" position.
10.Confirm that the buzzer sounds and the brake warning light

illuminates when the brake pedal is fully depressed 15 to 20
times within 10 seconds.

HBB Simple Check

1. Depress the brake pedal repeatedly for 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 HBB power supply system.

2. Check the change of pedal height by turning the ignition

switch to the "ON" position while depressing the brake
pedal. It is normal if the pedal is lowered at this time. If it is
not lowered, the system is defective.

Check Using Simple Tester

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 HBB power supply system.

ON-VEHICLE SERVICE

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BASIC BRAKE SYSTEM

35A-118

2. Connect a pressure gauge and a pedal depression gauge

as shown in the illustration and bleed air from the pressure
gauge.

3. Perform the operation test without booster according to the

following method.

Depress the brake pedal repeatedly more than 40 times
with the ignition switch at "LOCK" (OFF) position to bleed
pressure from the HBB power supply system. Measure
the relation between the brake pedal depressing force
and the hydraulic pressure.

Standard value:

4. Perform the operation test with booster according to the

following method.

Turn the ignition switch to the "ON" position and measure
the relation between the brake pedal depressing force
and the hydraulic pressure after pump motor was
stopped.

Standard value:

Brake Warning Light and Buzzer Operation Check

1. Chock the wheel and start the engine.
2. Hold the engine at the idling condition for more than 120

seconds.

BRAKE
PEDAL
DEPRESSING
FORCE N (lb)

HYDRAULIC PRESSURE kPa (psi)

FRONT BRAKE

REAR BRAKE

100 (22)

600 (87) and over

0 (0)

500 (112)

4,500 (653) and
over

0 (0)

BRAKE
PEDAL
DEPRESSING
FORCE N (lb)

HYDRAULIC PRESSURE kPa (psi)

FRONT BRAKE

REAR BRAKE

100 (22)

3,000

− 4,000

(435

− 580)

3,300

− 4,300

(479

− 624)

200 (45)

8,000

− 10,000

(1,160

− 1,450)

8,000

− 10,000

(1,160

− 1,450)

400 (90)

14,000

− 18,000

(2,030

− 2,611)

14,000

− 18,000

(2,030

− 2,611)

500 (112)

15,000

− 19,000

(2,175

− 2,756)

15,000

− 19,000

(2,175

− 2,756)

ACX00661 AB

PEDAL DEPRESSION GAUGE

PRESSURE
GAUGE

ON-VEHICLE SERVICE

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BASIC BRAKE SYSTEM

35A-119

CAUTION

Perform the check 120 seconds or more after turning the
ignition switch to the "ON" position.
3. Release the parking brake and fully depress the brake pedal

repeatedly 15 to 20 times in 10 seconds. Confirm that the
warning light comes on and the buzzer sounds.

HBB CHECK

M1351010500063

Continuity and Resistance Test of Pump Motor

1. Disconnect the HBB connectors.
2. Measure the resistance between the terminals at the HBB.

ACX01818

BRAKE WARNING LIGHT

BUZZER

AB

TESTER
CONNECTION

SPECIFIED
CONDITION

RESISTANCE VALUE

Ω

(REFERENCE VALUE)

2

− 7

Continuity

10 or less

2

− 8

Continuity

Approximately 33

2

− 31

Continuity

Less than 2

4

− 6

Continuity

Approximately 33

4

− 32

Continuity

Approximately 33

6

− 7

Continuity

Less than 2

6

− 32

Continuity

Less than 2

7

− 32

Continuity

Less than 2

8

− 31

Continuity

Approximately 33

31

− 32

Continuity

10 or less

ACX00662

ON-VEHICLE SERVICE

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BASIC BRAKE SYSTEM

35A-120

Pressure Switch (for Pump Control) Check

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 HBB power supply system.

2. Disconnect the HBB connector "A."
3. Measure the resistance between terminals No. 33 and No.

35 at the HBB connector "A."

4. If the resistance value exceeds the specified value, replace

the HBB master cylinder and hydraulic unit assembly.

5. With the HBB connector "A" disconnected, turn "ON" the

ignition switch to operate the pump motor. Then measure
the resistance between terminals No. 33 and No. 35 at the
HBB connector "A" while the pump motor is operating.

6. If the resistance value exceeds the specified value, replace

the HBB master cylinder and hydraulic unit assembly.

7. Connect the HBB connector "A."
8. Erase HBB diagnostic trouble codes (Refer to

P.35A-14

).

Pressure Switch (for Low-Pressure Warning)
Check

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

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

2. Disconnect the HBB connector "B."
3. Measure the resistance between terminals No. 1 and No. 5

at the HBB connector "B."

4. If the resistance value exceeds the specified value, replace

the HBB master cylinder and hydraulic unit assembly.

5. Next, turn the ignition switch to the "ON" position to operate

the pump motor. Then confirm that the pump motor is
stopped.

6. Measure the resistance between terminals No. 1 and No. 5

at the HBB connector "B."

TESTER
CONNECTION

SPECIFIED
CONDITION

RESISTANCE
VALUE k

Ω

33

− 35

Continuity

Approximately 1

TESTER
CONNECTION

SPECIFIED
CONDITION

RESISTANCE
VALUE

Ω

33

− 35

Continuity

Less than 2

ACX01809

CONNECTOR A

AC

TESTER
CONNECTION

SPECIFIED
CONDITION

RESISTANCE
VALUE k

Ω

1

− 5

Continuity

Approximately 5.7

ACX01810 AC

CONNECTOR B