2002 ISUZU AXIOM air condition

5C±9 POWER±ASSISTED BRAKE SYSTEM
Condition CorrectionPossible cause
Poor Brake ActionMaster cylinder faulty.Correct or replace.
Vacuum booster faulty.Correct or replace.
Level of brake fluid in reservoir too
low.Replenish and bleed.
Air in hydraulic circuit.Bleed
Disc brake caliper faulty.Clean or replace.
Water or oil on brake pads.Clean or replace.
Brake pads in poor contact with the
rotor.Correct
Brake pads worn.Replace
Brake disc rusted.Grind or replace.
Check valve in vacuum hose faulty.Correct or replace.

5C±11 POWER±ASSISTED BRAKE SYSTEM
330RW012
17. Bleed the air from the front wheel brake pipe
connection (2) by repeating steps 7 through 16.
Bleeding the Caliper
18. Bleed the air from each wheel in the order listed
below:

Right rear caliper or wheel cylinder

Left rear caliper or wheel cylinder

Right front caliper

Left front caliper
Conduct air bleeding from the wheels in the above
order. If no brake fluid comes out, it suggests that air
is mixed in the master cylinder. In this case, bleed air
from the master cylinder in accordance with steps 7
through 17, and then bleed air from the caliper or
wheel cylinder.
19. Place the proper size box end wrench over the
bleeder screw.
20. Cover the bleeder screw with a transparent tube, and
submerge the free end of the transparent tube in a
transparent container containing brake fluid.
21. Pump the brake pedal slowly three (3) times
(once/sec), then hold it depressed.
22. Loosen the bleeder screw until fluid flows through the
tube.
23. Retighten the bleeder screw.
24. Release the brake pedal slowly.
25. Repeat steps 21 through 24 until the air is completely
removed.
It may be necessary to repeat the bleeding procedure
10 or more times for front wheels and 15 or more
times for rear wheels.
26. Go to the next wheel in the sequence after each wheel
is bled.
Be sure to monitor reservoir fluid level.
27. Depress the brake pedal to check if you feel
ªsponginessº after the air has been removed from all
wheel cylinders and calipers.
If the pedal feels ªspongyº, the entire bleeding
procedure must be repeated.28. After the bleeding operation is completed on the each
individual wheel, check the level of the brake fluid in
the reservoir and replenish up to the ªMAXº level as
necessary.
29. Attach the reservoir cap.
If the diaphragm inside the cap is deformed, reform
it and install.
30. Stop the engine.
Flushing Brake Hydraulic System
It is recommended that the entire hydraulic system be
thoroughly flushed with clean brake fluid whenever new
parts are installed in the hydraulic system. Approximately
one quart of fluid is required to flush the hydraulic system.
The system must be flushed if there is any doubt as to the
grade of fluid in the system or if fluid has been used which
contains the slightest trace of mineral oil. All rubber parts
that have been subjected to a contaminated fluid must be
replaced.
Brake Pipes and Hoses
The hydraulic brake system components are
interconnected by special steel piping and flexible hoses.
Flexible hoses are used between the frame and the front
calipers, the frame and rear axle case and the rear axle
and the rear calipers.
When the hydraulic pipes have been disconnected for
any reason, the brake system must be bled after
reconnecting the pipe. Refer to
Bleeding the Brake
Hydraulic System
in this section.
Brake Hose Inspection
The brake hose should be inspected at least twice a year.
The brake hose assembly should be checked for road
hazard, cracks and chafing of the outer cover, and for
leaks and blisters. Inspect for proper routing and
mounting of the hose. A brake hose that rubs on
suspension components will wear and eventually fail. A
light and mirror may be needed for an adequate
inspection. If any of the above conditions are observed on
the brake hose, adjust or replace the hose as necessary.
CAUTION: Never allow brake components such as
calipers to hang from the brake hoses, as damage to
the hoses may occur.

5C±22
POWER±ASSISTED BRAKE SYSTEM
Master Cylinder Assembly
Master Cylinder Assembly and Associated Parts
330RW010
Legend
(1) Electrical Connector
(2) Master Cylinder
(3) 2 attaching Nuts(4) P&B Valve and Bracket
(5) Brake Pipes
(6) Spacer and 2 gaskets
Removal
CAUTION: When removing the master cylinder from
the vacuum booster, be sure to get rid of the internal
negative pressure of the vacuum booster (by, for
instance, disconnecting the 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 the 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. Disconnect electrical connector.
2. Remove brake pipes and after disconnecting the
brake pipe, cap or tape the openings of the brake pipe
to prevent the entry of foreign matter.
3. Remove 2 attaching nuts.
4. Remove P&B valve and bracket.5. Remove master cylinder.
6. Remove spacer and the 2 gaskets.
Inspection and Repair
Master Cylinder
The master cylinder is not repairable and must be
replaced as a complete assembly if found defective.
Inspection
Excessive brake pedal travel, malfunction or dragging
brake suggests that the master cylinder is defective. In
such cases perform the following visual check:
Visual Check
Make parts replacement as required if wear, distortion,
nicks, cuts, corrosion, or other abnormal conditions are
found through the following parts inspection:

Master cylinder body

Fluid reservoir

O±ring

5C±29 POWER±ASSISTED BRAKE SYSTEM
Inspection and Repair
Visual Check
Make necessary parts replacement if cuts, nicks,
excessive wear, or other abnormal conditions are found
through inspection. Check the following parts:

Yoke clevis

Valve body guard

Silencer

Filter plate and seal assembly
Installation
1. Install plate and seal assembly.
2. Install retainer.3. Install 2 gaskets and spacer.
4. Install filter.
5. Install silencer.
6. Install valve body guard.
7. Install retainer.
8. Install lock nut and yoke clevis and tighten to the
specified torque.
Torque: 20 N´m (15 lb ft)
9. Install vacuum booster, refer to
Vacuum Booster in
this section.
10. Install master cylinder, refer to
Master Cylinder in this
section and after installation, perform brake pedal
check and adjustment. Refer to
Brake Pedal in this
section.
Vacuum Booster Overhaul
Vacuum Booster
The vacuum booster cannot be disassembled for repair.
Replace a defective vacuum booster with a new one.

5C±40
POWER±ASSISTED BRAKE SYSTEM
5. Insert a block of wood into the caliper and force out
the piston by blowing compressed air into the caliper
at the flexible hose attachment. This procedure must
be done prior to removal of the dust boot.
Remove piston.
WARNING: D O N O T P L A C E Y O U R F I N G E R S I N
FRONT OF THE PISTON IN AN ATTEMPT TO CATCH
OR PROTECT IT WHEN APPLYING COMPRESSED
AIR. THIS COULD RESULT IN PERSONAL INJURY.
CAUTION: Use just enough air to ease the piston
out of the bore. If the piston is blown out, it may be
damaged.
302RS017
6. Remove dust boot: piston.
7. Remove piston seal.
8. Remove bleeder with cap.
9. Remove caliper body.
Inspection and Repair
Make necessary parts replacement, if wear, damage,
corrosion or any other abnormal conditions are found
through inspection.
Check the following parts:

Rotor

Cylinder body

Cylinder bore

Piston

Guide bolt, lock bolt

Support bracket
NOTE: The piston seal, boot ring and dust boot are to be
replaced each time the caliper is overhauled. Discard
these used rubber parts and replace them with new ones.
Reassembly
1. Install caliper body.
2. Install bleeder with cap and tighten the cap to the
specified torque.
Torque: 8 N´m (69 lb in)
3. Apply special rubber grease to the piston seal and
cylinder wall, then insert the piston seal into the
cylinder. The special rubber grease is included in the
repair kit.
302RS018
4. When inserting the piston into the cylinder, use finger
pressure only and do not use a mallet or other impact
tool, since damage to the cylinder wall or piston seal
can result.
Install piston.
302RS019

5C±51 POWER±ASSISTED BRAKE SYSTEM
Disassembly
1. Remove guide bolt.
2. Remove lock bolt.
3. Remove dust boot; guide bolt and lock bolt.
4. Remove dust boot ring, using a small screwdriver.
302RS016
5. Insert a block of wood into the caliper and force out
the piston by blowing compressed air into the caliper
at the flexible hose attachment. This procedure must
be done prior to removal of the dust boot.
Remove piston.
WARNING: D O N O T P L A C E Y O U R F I N G E R S I N
FRONT OF THE PISTON IN AN ATTEMPT TO CATCH
OR PROTECT IT WHEN APPLYING COMPRESSED
AIR. THIS COULD RESULT IN PERSONAL INJURY.
CAUTION: Use just enough air to ease the piston
out of the bore. If the piston is blown out, it may be
damaged.
302RS017
6. Remove dust boot: piston.
7. Remove piston seal.
8. Remove bleeder with cap.
9. Remove caliper body.
Inspection and Repair
Make necessary parts replacement, if wear, damage,
corrosion or any other abnormal conditions are found
through inspection.
Check the following parts:

Rotor

Cylinder body

Cylinder bore

Piston

Guide bolt, lock bolt

Support bracket
NOTE: The piston dust seal and dust boot are to be
replaced each time the caliper is overhauled. Discard
these used rubber parts and replace with new ones.
Reassembly
1. Install caliper body.
2. Install bleeder with cap and tighten the cap to the
specified torque.
Torque: 8 N´m (69 lb ft)
3. Install piston seal and apply special rubber grease to
the piston seal and cylinder wall, then insert the piston
seal into the cylinder. The special rubber grease is
included in the repair kit.
302RS018
4. When inserting the piston into the cylinder, use finger
pressure only and do not use a mallet or other impact
tool, since damage to the cylinder wall or piston seal
can result.
Install piston.

5C±58
POWER±ASSISTED BRAKE SYSTEM
Disassembled View
305RS006
Legend
(1) Boot
(2) Piston Assembly
(3) Piston Cup
(4) Return Spring
(5) Bleeder
(6) Wheel Cylinder
Disassembly
1. Remove boot (1) and piston assembly (2).
2. Remove piston cup (3) from piston assembly (2).
3. Remove return spring (4) and bleeder (5) from wheel
cylinder (6).
Inspection and Repair
1. Make necessary parts replacement if wear, damage,
corrosion or any other abnormal condition are found
through inspection.
Check the following parts;

Wheel cylinder body

Cylinder bore

Piston

Return spring

BleederNOTE: Replace the piston cups and boots each time the
wheel cylinder is overhauled. Discard these used rubber
parts and replace with new ones.
Reassembly
1. Lubricate the cylinder bore with clean rubber grease.
305RS007
2. Install bleeder (5) to wheel cylinder (6).
Torque: 10 N´m (8 lb ft)
305RS008

5C±67 POWER±ASSISTED BRAKE SYSTEM
General Diagnosis
ConditionPossible causeCorrection
Brake PullTire inflation pressure is unequal.Adjust
Front wheel alignment is incorrect.Adjust
Unmatched tires on same axle.Tires with approx. the same amount
of tread should be used on the same
axle.
Restricted brake pipes or hoses.Check for soft hoses and damaged
lines. Replace with new hoses and
new double walled steel brake
piping.
Water or oil on the brake pads.Clean or replace.
Brake pads hardened.Replace
Brake pads worn excessively.Replace
Brake rotor worn or scored.Grind or replace.
Disc brake caliper malfunctioning.Clean or replace.
Front hub bearing preload incorrect.Adjust or replace.
Loose suspension parts.Check all suspension mountings.
Loose calipers.Check and tighten the bolts to
specifications.
Brake Roughness or Chatter
(Pulsates)Excessive lateral runout.Check per instructions. If not within
specifications, replace or machine
the rotor.
Parallelism not within specifications.Check per instructions. If not within
specifications, replace or machine
the rotor.
Pad reversed (steel against iron).Replace the brake pad and machine
rotor to within specifications.
Excessive Pedal EffortMalfunctioning vacuum booster.Check the vacuum booster operation
and repair, if necessary.
Partial system failure.Check the front and rear brake
system for failure and repair. Also,
check the brake warning light. If a
failed system is found, the light
should indicate failure.
Excessively worn pad.Check and replace pads in sets.
Piston in caliper stuck or sluggish.Remove caliper and rebuild.
Fading brakes due to incorrect pad.Remove and replace with original
equipment pad or equivalent.
Vacuum leak to vacuum booster.Check for ruptured or loose hose.
Check the direction of check valve
within vacuum hose.Correct vacuum hose direction.
Grease on the brake pads.Replace or clean.
Excessive Brake Pedal TravelAir in hydraulic circuit.Bleed the hydraulic circuit.
Level of brake fluid in the reservoir
too low.Replenish brake fluid reservoir to
specified level and bleed hydraulic
circuit as necessary.
Master cylinder push rod clearance
excessive.Adjust
Leakage in hydraulic system.Correct or replace defective parts.