Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1187

POWER-ASSISTED BRAKE SYSTEM

5C–15

P & B (Proportioning and Bypass) Valve

P & B (Proportioning and Bypass)
Valve Sectional View

350RW014

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The P&B valve contains two sections, each serving a
different function.
The proportioning section of the P&B valve proportions
outlet pressure to the rear brakes after a predetermined
rear input pressure has been reached. This is done to
prevent rear wheel lock up on the vehicles with light rear
wheel loads. The valve has a by–pass feature which
assures full system pressure to the rear brakes in the
event of front brake system malfunction. Also full front
pressure is retained in the event of rear brake
malfunction.
The  P&B valve is not repairable and must be replaced
as complete assembly. 

Removal

1. The P&B valve is not repairable and must be

replaced as a complete assembly. Care must be
taken to prevent brake fluid from contacting any
painted surface. 

2. Remove hydraulic pipes (1) and plug the pipes (1)

to prevent the loss of fluid or the entrance of dirt.

3. Remove bolt (3).

4. Remove P&B valve (2).

350R200003

Installation

1. Install P&B valve (2).

2. Install bolt (3) and tighten the bolt to the specified

torque.

Torque: 22 N·m (16 lb ft)

3. Install hydraulic pipes (1) and tighten the bolt to the

specified torque.

Torque: 12 N·m (104 lb in)

4. After installing the brake pipes, bleed the brakes as

described in Bleeding Brake Hydraulic System in
this section.

Legend

(1) Master Cylinder (Secondary)
(2) Master Cylinder (Primary)
(3) Rear Brake
(4) Front Brake

5C–16

POWER-ASSISTED BRAKE SYSTEM

Main Data and Specifications

Torque Specifications

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POWER-ASSISTED BRAKE SYSTEM

5C–17

Brake Pedal

Checking Pedal Height

The push rod serves as the brake pedal stopper when
the pedal is fully released. Brake pedal height
adjustment should be performed as follows:

Adjust Brake Pedal

310R200002

1. Measure the brake pedal height after making sure

the pedal is fully returned by the pedal return spring.
Pedal height must be measured after starting the
engine and stepping on it several times.

Pedal Free Play: 6-10 mm (0.23-0.39 in)

Pedal Height: 173-185 mm (6.81-7.28 in)

NOTE:  Pedal free play must be measured after turning
off the engine and stepping on the brake pedal firmly
five times or more.

2. If the measured value is not within the above range,

adjust the brake pedal as follows:

a. Disconnect the stoplight switch connector.

b. Loosen the stoplight switch lock nut.

c.

Rotate the stoplight switch so that it moves
away from the brake pedal. 

d. Loosen the lock nut (1) on the push rod.

e. Adjust the brake pedal to the specified height by

rotating the push rod in the appropriate
direction.

f.

Tighten the lock nut to the specified torque.

Torque: 20 N·m (15 lb ft)

g. Adjust the stoplight switch (2) to the specified

clearance (between the switch housing and the
brake pedal) by rotating the switch housing.

Clearance: 0.5–1.0 mm (0.02–0.04 in)

310RY00005

NOTE:  While adjusting the stoplight switch, make sure
that the threaded part of the stoplight switch does not
push the brake pedal.

h. Tighten the stoplight switch lock nut.

i.

Connect the stoplight switch connector.

Checking Pedal Travel

310R200002

1. Pedal height must be measured after starting the

engine and revving it several times to apply vacuum
to the vacuum booster fully.

NOTE:  Pedal height must be 95 mm (3.7 in) or more
when about 50 kg (110.25 lb) of stepping force is
applied.

2. If the measured value is lower than the above

range, air may still be present in the hydraulic
system Perform the bleeding procedure.

5C–18

POWER-ASSISTED BRAKE SYSTEM

Brake Pedal and Associated Parts

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Removal

1. Disconnect the battery “–” terminal cable, and wait

at least 5 minutes.

2. Disconnect the yellow 3 way SRS connector located

under the steering column.

3. Remove the engine hood opening lever.

4. Remove lower cover (8).

5. Remove driver knee bolster (10).

6. Disconnect the stop light switch connector (3).

Disconnect the anti-theft control module connector.
Refer to Body and Accessories section.

7. Remove snap pin (4) and push rod pin (7).

8. Remove the steering column shaft fixing bolt and

nut (9) on the steering wheel side, and lower the
steering column shaft.

9. Remove the brake pedal bracket assembly (1).

10. Remove return spring (5).

11. Remove fulcrum pin and nut (2).

12. Remove pedal assembly (6).

Installation

1. Apply grease to the entire circumference of the

fulcrum pin.

2. Install pedal assembly (6) and fulcrum pin and nut

(2).
Tighten the nut (2) to the specified torque.

Torque: 35 N·m (26 lb ft)

3. Install the brake pedal bracket assembly (1).

Tighten the bolts and nuts soecified torque.

Torque: 15 N·m (11 lb ft)

4. Install return spring (5).

5. Adjust pedal free travel.

Refer to Brake Pedal Adjustment in this section.

Legend

(1) Brake Pedal Bracket Assembly
(2) Fulcrum Pin and Nut
(3) Connector
(4) Snap Pin
(5) Return Spring

(6) Peadl Assembly
(7) Push Rod Pin
(8) Lower Cover
(9) Bolts and Nut

(10) Driver Knee Bolster