Antilock Brake System Bleeding Procedures

NOTE: When bleeding the ABS brake system, there are some special precautions you should follow. Although the main brake fluid supply is contained in the master cylinder, there is also brake fluid contained in both accumulators. Therefore it is necessary to periodically turn the ignition key to the on position throughout the brake bleeding procedure to allow the booster pump and motor assembly to keep the proper amount of fluid stored in both accumulators.

Fig.39 Fluid Level:

BLEEDING THE HYDRAULIC SYSTEM
1. Fill reservoir to V-shaped MAX fill mark.
2. Bleed brakes in following sequence: right rear; left rear; right front; left front.
3. Attach bleed hose to caliper or wheel cylinder bleed fitting.
4. Immerse end of bleed hose in glass container partially filled with brake fluid. Be sure hose end is submerged in fluid.
5. Turn ignition switch On to cycle pump.
6. Have helper apply brake pedal to pressurize system.
7. Open bleed screw 1/2 turn.
8. Close bleed screw when fluid entering glass container is free of bubbles.
9. Check reservoir fluid level and add fluid to Max fill mark.

CAUTION: Do not allow the master cylinder reservoir to run dry while bleeding the brakes. Running dry will allow air to re-enter the system making a second bleeding operation necessary. More importantly, if air re-enters the system, it could damage the pump seriously enough to require replacement.

10. Repeat bleeding operation at remaining wheels.