OPERATION AND LEAKAGE CHECK
CHECK ALL OF THE FOLLOWING ITEMS
| Component | Procedure |
|---|---|
| Brake Booster (A) | Check brake operation by applying the brakes during a test drive. If the brakes do not work properly, check the brake booster. Replace the brake booster as an assembly if it does not work properly or if there are signs of leakage. |
| Piston cup and pressure cup inspection (B) | Check brake operation by applying the brakes. Look for damage or signs of fluid leakage. Replace the master cylinder as an assembly if the pedal does not work properly or if there is damage or signs of fluid leakage. |
| Check for a difference in brake pedal stroke between quick and slow brake applications. Replace the master cylinder if there is a difference in pedal stroke | |
| Brake hoses (C) | Look for damage or signs of fluid leakage. Replace the brake hose with a new one if it is damaged or leaking. |
| Caliper piston seal and piston boots (D) | Check brake operation by applying the brakes. Look for damage or signs of fluid leakage. If the pedal does not work properly, the brakes drag, or there is damage or signs of fluid leakage, disassemble and inspect the brake caliper. Replace the boots and seals with new ones whenever the brake caliper is disassembled. |
| Wheel cylinder piston cup and dust cover (E) | Check brake operation by applying the brakes. Look for damage or signs of fluid leakage. If the pedal does not work properly, the brakes drag, or there is damage or signs of fluid leakage, replace the wheel cylinder. |
BRAKE COMPONENT PROCEDURE REFERENCE
Scheme 2
DESCRIPTION
Do not disassemble the proportioning valve. The proportioning valve makes the ideal distribution of fluid pressure to the front and rear brakes to prevent the brakes from skidding in the event of rear wheel lock up and to obtain higher brake efficiency within the range of service brake application.
Scheme 3
Scheme 4
- Remove the front brake tube (B) and rear brake tube (C) from the master cylinder (A).
- Connect two pressure gauges (D); one to the output valve of the front (B) and rear (C) brake. NOTE: Be sure to bleed the system after connecting the pressure gauges.
- With the brake applied, measure the front pressure and the rear pressure. If the measured pressures are within the specified range as illustrated, the proportioning valve is good
- Reconnect the brake lines in their original positions and bleed the brake system. NOTE: This table shows characteristics of the proportioning valve as the pressure increases. VALVE OUTPUT CHART Front (Output of master cylinder) Rear (Output of proportioning valve) A: 35 kg/cm 2 (3.43 MPa, 498 psi) A': 35 kg/cm 2 (3.43 MPa, 498 psi) B: 80 kg/cm 2 (7.85 MPa, 1138 psi) B': 49.4 ± 3.0 kg/cm 2 (4.84 ± 0.3 MPa, 703 ± 42.7 psi)
Scheme 5
Scheme 6
Scheme 7
- Raise the vehicle and make sure it is securely supported. Remove the rear wheel.
- Release the parking brake.
- Remove the guide rod bolt (B). After raise the caliper assembly (A), support it with a wire.
- Remove the pad shim (A) and pad assembly (C) from caliper bracket (B).
Scheme 8
- Remove all rust and contamination from the disc surface, and then measure the disc thickness at 8 positions at least. Rear brake disc thickness Standard value: 10.0 mm (0.39 in) Limit: 8.4 mm (0.33 in)
- Thickness variation should not exceed 0.01 mm (0.0004 in) (circumference) and 0.01 mm (0.0004 in) (radius) at any directions.
- If wear exceeds the limit, replace the discs and pad assembly for left and right of the vehicle.
Scheme 9
- Check the pad wear. Measure the pad thickness and replace it, if it is less than the specified value. Pad thickness Standard value: 10.0 mm (0.39 in) Service limit: 2.0 mm (0.0787 in)
- Check that grease is applied, and the pad and backing metal for damage.
Scheme 10
- Place a dial gauge(A) about 5mm (0.2 in) from the outer circumference of the brake disc, and measure the run out of the disc. Brake disc run out Limit: 0.03mm (0.0012 in) or less
- If the run out of the brake disc exceeds the limit specification, replace the disc, and then measure the run out again.
- If the run out does not exceed the limit specification, install the brake disc after turning it 180° and then check the run out of the brake disc again.
- If the run out cannot be corrected by changing the position of the brake disc, replace the brake disc.
Scheme 11
- Remove the brake disc from hub using M8 screw (A) if the brake disc has been seized with the hub due to corrosion or overheat. NOTE: Be careful not to use the hammer. The disc can be damaged if you remove the disc from the hub by hammer.
Scheme 12
Scheme 13
- Install the pad retainers to the caliper.
- Check the foreign material at the pad shim (A) and the back of the pads (C).
- Contaminated brake discs or pads reduce stopping ability. Keep grease off the discs and pads.
- Install the brake pads (C) and pad shim (A) on the caliper bracket (B).
- If you are reusing the pads, always reinstall the brake pads in their original positions to prevent a momentary loss of braking efficiency. Push in the piston using SST(09581-11000) so that the caliper will fit over the pads. Make sure that the piston boot is in position to prevent damaging it when pivoting the caliper down.
- Pivot caliper down into position. Being careful not to damage the pin boot, install the guide rod bolt (A) and tighten it to the specified torque.
- Install the brake caliper.
- After installation, check for leaks at hose and line joints and connections, and retighten if necessary.
- Depress the brake pedal several times to make sure the brakes work, then test-drive. NOTE: Engagement of the brake may require a greater pedal stroke immediately after the brake pads have been replaced as a set. Several applications of the brake pedal will restore the normal pedal stroke.