GM: Electra/Park Avenue/Ninety-Eight 1990-1993

Bleeding

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Fig. Fig. 1 Bleeding the front brakes



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Fig. Fig. 2 Bleeding the rear brakes

The purpose of bleeding the brakes is to expel air trapped in the hydraulic system. The system must be bled whenever the pedal feels spongy, indicating that compressible air has entered the system. It must also be bled whenever the system has been opened or repaired. You will need a helper for this job.

Never reuse brake fluid which has been bled from the brake system. Brake fluid should be changed every few years; it wears out due to moisture being absorbed which lowers the boiling point. Old brake fluid is often the cause of spongy brakes returning a week or so after bleeding the system. If all parts are ok, try changing the brake fluid by repeated bleeding.

This procedure is not for Teves ii high Pressure Anti-lock brake system. If your car has anti-lock brakes, check the proper anti-lock brake system procedures for your car.

  1. Fill the master cylinder reservoirs with brake fluid. Keep the level at least 1 / 2 full during the bleeding operation.
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  3. If air is in the master cylinder, purge it first. Disconnect and plug the brake lines at the master cylinder. Fill the master cylinder until fluid begins to flow from the front pipe connector port.
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  5. Connect the brake lines to the master cylinder and tighten.
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  7. Have your assistant depress the brake pedal slowly one time and hold, tighten the connection and then release the brake pedal slowly. Wait 15 seconds.
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  9. Repeat the sequence until all the air has been removed from the master cylinder bore.
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  11. After all the air has been removed from the front connections repeat the same procedure at the rear connections of the master cylinder.
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  13. Individual wheel cylinders and calipers are bled only after all the air has been removed from the master cylinder.
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  15. To bleed the caliper or the wheel cylinder perform the following:
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    1. Fill the master cylinder reservoirs with brake fluid. Keep the level at least 1 / 2 full during the bleeding operation.
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    3. Raise and support the vehicle safely. Attach a transparent tube over the bleeder screw.
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    5. Using an assistant, depress the brake pedal slowly, one time and hold.
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    7. Loosen the bleeder valve to purge the air from the cylinder.
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    9. Tighten the bleeder screw and slowly release the brake pedal. Wait 15 seconds.
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    11. Repeat this sequence until all the air is removed. The bleeding sequence is right rear, left front, left rear and right front.
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    13. Lower the vehicle and refill the master cylinder.
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