Isuzu Trooper (1998-2002 year). Service manual - part 222

5C – 40 POWER ASSISTED BRAKE SYSTEM

REMOVAL

CAUTION:
When removing master cylinder from vacuum
booster, be sure to get rid of the internal negative
pressure of the vacuum booster (by, for instance,
disconnecting vacuum hose) in advance.
If any negative pressure remains in the vacuum
booster, the piston may possibly come out when the
master cylinder is being removed, letting the brake
fluid run out.
While removing master cylinder, further, do not hold
the piston as it can be easily pulled out.
Outside surface of the piston is the surface on which
seals are to slide. Care should be taken to keep the
surface free of cuts and dents.

1. Electrical Connector

2. Brake Pipes

•

After disconnecting the brake pipe, cap or tape
the openings of the brake pipe to prevent the
entry of foreign matter.

3. 2 Attaching Nuts

4a. P & B Valve and Bracket

4b.3-way Connector and Bracket (Vehicle with LSPV

Only)

5. Master Cylinder

6. Spacer and 2 Gaskets

INSTALLATION

6. Spacer and 2 Gaskets

5. Master Cylinder

•

When replacing the master cylinder or vacuum
booster or both, always measure the vacuum
booster push rod protrusion and adjust it as
necessary. (Refer to Vacuum Booster Assembly in
this section.)

4a. P & B Valve and Bracket

4b.3-way Connector and Bracket (Vehicle with LSPV

Only)

3. 2 Attaching Nuts

•

Tighten the attaching nuts to the specified torque.

Attaching Nut Torque

N·m (kg·cm / lb·in)

13 (130 / 113)

2. Brake Pipes

•

Tighten the brake pipe to the specified torque.

Brake Pipe Torque

N·m (kg·m / lb·ft)

Master Cylinder Side

Others

12 (1.2 / 9)

16 (1.6 / 12)

1. Electrical Connector

POWER ASSISTED BRAKE SYSTEM  5C – 41

VACUUM BOOSTER ASSEMBLY

1

P&B valve
equipped
vehicle

LSPV
equipped
vehicle

2

4

3

3

5

Removal Steps

1.

Master cylinder

2.

Vacuum hose

3.

Yoke clevis

4.

Vacuum booster fixing nut

5.

Vauum booster

Installation Steps

To install, follow the removal steps in the
reverse order.

This illustration is based on the LHD model.

331RW010

5C – 42 POWER ASSISTED BRAKE SYSTEM

REMOVAL

•

Before removing the vacuum booster assembly,
disconnect and remove brake pipes.

1. Master Cylinder

•

Refer to Master Cylinder Assembly in this Section.

CAUTION:
When removing master cylinder from vacuum booster,
be sure to get rid of the internal negative pressure of
the vacuum booster (by, for instance, disconnecting
vacuum hose) in advance.
If any negative pressure remains in the vacuum
booster, the piston may possibly come out when the
master cylinder is being removed, letting the brake
fluid run out.
While removing master cylinder, further, do not hold
the piston as it can be easily pulled out.
Outside surface of the piston is the surface on which
seals are to slide. Care should be taken to keep the
surface free of cuts and dents.

2. Vacuum Hose

3. Yoke Clevis

•

Disconnect the yoke clevis from the brake pedal.

4. Vacuum Booster Fixing Nut

5. Vacuum Booster

INSPECTION AND REPAIR

Vacuum Hose

Inspect the check valve (1), which is installed inside
the vacuum hose.
1) Air should pass freely from the vacuum booster

side (3) to the engine side (2).

2) Air should not pass from the engine side (2) to the

vacuum booster side (3). If it does, the check valve
is inoperative and vacuum hose must be replaced.

INSTALLATION

5. Vacuum Booster

Vacuum booster push rod adjustment.

NOTE:
When replacing either master cylinder or vacuum
booster, be sure to measure push rod, and adjust
required.

Push rod gauge: 5-8840-2300-0 (J-39216)

Vacuum pump: 5-8840-0279-0 (J-23738-A)

Push rod support: 5-8840-2305-0 (J-39241)
1) Remove retainer from vacuum booster front shell

using a small screwdriver. Then gently draw plate
and seal assembly out of the shell inside.

ENG

1

2

3

360RX001

POWER ASSISTED BRAKE SYSTEM  5C – 43

2) Set push rod gauge on vacuum booster, and

apply negative pressure by means of vacuum
pump so that the pressure in the vacuum booster
becomes 500 mm Hg.

NOTE:
Be sure to apply. NEGATIVE pressure after installing
a push rod gauge on vacuum booster.

3) Measure dimension L

Dimension L (Standard)

mm

0 ± 0.1

5-8840-0279-0

5-8840-2300-0

L

5-8840-2300-0

4) If dimension L is out of the standard range,

adjust push rod using the special tool.

5) Mount plate and seal assembly in vacuum

booster front shell. Then install retainer.

4. Vacuum Booster Fixing Nut

Vacuum Booster Fixing Nut Torque

N·m (kg·m / lb·ft)

21 (2.1 / 16)

3. Yoke Clevis

2. Vacuum Hose

•

In case of the gasoline engine model, make sure
that the arrow on the hose points in the direction of
the engine.

1. Master Cylinder

•

Refer to Master Cylinder Assembly in this Section.

5-8840-2305-0 

T-wrench