Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 199

5C–113

POWER–ASSISTED BRAKE SYSTEM

NOTE: Do not over stretch the return spring.

305RS003

9. Remove upper (inner) return spring (9).

10. Remove hold-down spring and cup (3) and hold-down

pin (16).

11. Remove Trailing shoe assembly (7) with parking

brake lever (16).

12. Remove parking brake cable from parking brake lever

(11).

13. Remove retainer (14), wave washer (13), and parking

brake lever (11).

Brake Lining Inspection

Check the shoe assemblies for wear by removing brake
drum.
Replace the shoe assemblies, if lining thickness is less
than 1.0 mm (0.039 in).
The shoe assemblies have a wear indicator that makes a
noise when the linings wear to a degree where
replacement is required.

Minimum limit: 1.0 mm (0.039 in)

305RS001

Installation

1. Apply grease lightly to back place A.

305RW002

Legend

(1) Place A (3 portions for each side)

2. Install parking brake lever (11), wave washer (13),

and retainer (14).

3. Install trailing shoe assembly (7) with parking brake

lever (16).

4. Install the parking brake cable to parking brake lever

(11).

5. Install hold-down pin (16) and hold-down spring and

cup (3).

6. Install upper (inner) return spring (9).
7. Install leading shoe assembly (8) with upper (inner)

return spring (9).

NOTE: Do not over stretch the return spring.

305RS003

5C–114 POWER–ASSISTED BRAKE SYSTEM

8. Install adjuster assembly (12).
9. Install hold-down pin (15) and hold-down spring and

cups (4).

10. Install lower return spring (5).

D

Use brake spring tool.

11. Install auto adjuster lever (10).

12. Install upper (outer) return spring (6).

D

Use brake spring tool.

13. Install brake drum (2).

D

Adjust the brakes, refer to the 

Drum Brake

Adjustment in this section.

14. Install wheel and tire assembly (1).

D

Refer to 

Wheels and Tires in wheel and Tire System

section.

Drum Brake Adjustment (4

×

2 Model)

NOTE: All brakes are self-adjusting. Brakes are adjusted
by repeated stepping on the brake pedal. (After stepping
on the pedal and releasing it, the rear auto adjuster, in the
rear brake, produces a clicking sound.
The same operation should be repeated until the sound
disappears.)
Take the following steps after overhauling the rear brake
assembly.

1. Move the parking brake handle to its fully released

position.

2. Parking cable must be loosened sufficiently. (Loosen

the adjust nut and the lock nut.)

3. Repeat stepping on the brake pedal firmly, and

releasing it until the clicking sound can no longer be
heard.
If the difference between the brake drum inside
diameter and diameter of the brake shoes is adjusted
to be 0,5 mm, the number of times for depressing the
brake pedal can be reduced.

4. Remove the drum. Measure the brake drum inside

diameter and diameter of the brake shoes.

Shoe clearance: 0.25-0.4 mm (0.0098-0.0157 in)

If incorrect, check the brake auto-adjusting system.

5. Rotate the adjust nut until all slack disappears from

the cable. Set the adjust nut.

6. Applying about 30 kg (66 lb) of force, pull the parking

brake handle to its fully set position three or four
times.

7. If the parking brake is properly adjusted, the travel

between the fully disengaged position and the fully
engaged position will be between 9 and 11 notches.
If the traveling range is not within these limits, again
repeat steps 1 through 5.
After adjusting has been done, check to see if the rear
wheel rotates smoothly without drag when turned by
hand.

Servicing The Brake Drum

Whenever the brake drums are removed, they should be
thoroughly cleaned and inspected for cracks, scores,
deep grooves and out-of-round.

Cracked, Scored or Grooved Drum

A cracked drum is unsafe and must be replaced.
Do not attempt to weld a cracked drum.
Smooth any slight scores. Heavy or extensive scoring will
cause excessive brake lining wear, and it will probably be
necessary to machine the drum braking surface.
If the brake linings are slightly worn and the drum is
grooved, the drum should be polished with fine emery
cloth but should not be machined. At this stage,
eliminating all the grooves in the drum and smoothing the
ridges on the lining would require the removal of too much
metal and lining. If left alone, the grooves and ridges
match and satisfactory service can be obtained. If brake
linings are to be replaced, a grooved drum should be
machined. Using a grooved drum with new linings will
create inefficient braking performance and cause the
linings to wear quicker.

Out-Of-Round Drum

An out-of-round drum makes accurate brake shoe
adjustment impossible and is likely to cause excessive
wear to other parts of the brake mechanism due to its
eccentric action. An out-of-round drum can also cause
severe and irregular tire tread wear as well as a pulsing
brake pedal. When the braking surface of a brake drum
exceeds the specification limit of 0.15 mm (0.006 in) in
out-of-round, the drum should be machined to true up the
braking surface. Out-of-round can be accurately
measured with an inside micrometer fitted with proper
extension rods. When measuring a drum for out-of-round
and wear, take measurements at the open and closed
edges of machines surfaces and at right angles to each
other.

Maximum out-of-round: 0.15 mm (0.006 in)

420RS034

5C–115

POWER–ASSISTED BRAKE SYSTEM

Machining The Drum

If a drum is to be machined, only enough metal should be
removed to obtain a true, smooth braking surface. If a
drum does not clean-up when machined to a maximum
diameter, it must be replaced. Removal of more metal will

affect dissipation of heat and may cause distortion of the
drum.
After refinishing, replace any drum that exceeds a
maximum inside diameter of 296.5 mm (11.673 in). Do
not use a brake drum that is not within the specification.

Maximum inside diameter: 296.5 mm (11.673 in)

Wheel Cylinder Assembly (4

×

2 Model)

Wheel Cylinder Assembly and Associated Parts

305RW003

Legend

(1) Brake Linings
(2) Wheel Cylinder

(3) Bolts
(4) Brake Pipe

Removal

1. Remove brake linings (1).

D

Refer to 

Brake Lining and Associated Parts in this

section.

2. Remove brake pipe (4).

D

Plug the opening in the line to prevent fluid loss and
contamination.

3. Remove bolts (3) and wheel cylinder (2).

Installation

1. Install wheel cylinder (2) and tighten bolts (3) to the

specified torque.

Torque: 10 N·m (8 lb ft)

2. Install brake pipe (4) and tighten the nut to the

specified torque.

Torque: 16 N·m (12 lb ft)

3. Install brake linings (1).

D

Refer to 

Brake Lining Replacement in this section.

D

Bleed brake system. Refer to 

Hydraulic Brake in

this section.

5C–116 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;

D

Wheel cylinder body

D

Cylinder bore

D

Piston

D

Return spring

D

Bleeder

NOTE: 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