If you have disconnected the brake pipes from the master cylinder, you must bleed the master cylinder.
- Ensure that the brake master cylinder reservoir is full to the maximum-fill level. If necessary add Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. If removal of the reservoir cap and diaphragm is necessary, clean the outside of the reservoir on and around the cap prior to removal.
- With the rear brake pipe installed securely to the master cylinder, loosen and separate the front brake pipe from the front port of the brake master cylinder. Allow a small amount of brake fluid to gravity bleed from the open port of the master cylinder.
- Reconnect the brake pipe to the master cylinder port and tighten securely.
- Have an assistant slowly depress the brake pedal fully and maintain steady pressure on the pedal.
- Loosen the same brake pipe to purge air from the open port of the master cylinder.
- Tighten the brake pipe, then have the assistant slowly release the brake pedal.
- Wait 15 seconds, then repeat steps 2-6 until all air is purged from the same port of the master cylinder.
- With the front brake pipe installed securely to the master cylinder - after all air has been purged from the front port of the master cylinder - loosen and separate the rear brake pipe from the master cylinder, then repeat steps 2-7.
- After completing the final master cylinder port bleeding procedure, ensure that both of the brake pipe-to-master cylinder fittings are properly tightened.