Flushing Brake System
WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect the brake fluid for the following conditions, indicating brake fluid contamination:
- Fluid separation, indicating two types of fluid are present; a substance other than the recommended brake fluid has been introduced into the brake hydraulic system.
- Swirled appearance - oil-based substance.
- Layered appearance - silicone-based substance.
- Fluid discoloration, indicating the presence of moisture or particles that have been introduced into the brake hydraulic system.
- Cloudy appearance - moisture.
- Dark appearance/suspended particles in fluid - dirt, rust, corrosion, brake dust.
- Fluid separation, indicating two types of fluid are present; a substance other than the recommended brake fluid has been introduced into the brake hydraulic system.
- Inspect the master cylinder reservoir cap diaphragm and the reservoir-to-master cylinder grommets for swelling, indicating brake fluid contamination.
- If the brake fluid was contaminated with an oil-based or a silicone-based substance, indicated by fluid separation and/or a swollen master cylinder reservoir cap diaphragm and/or swollen reservoir-to-master cylinder grommets, perform the following:
- Remove all of the following components listed from the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system:
- Master Cylinder
- Brake Hoses
- Brake Calipers
- Brake Pressure Modulator Valve (BPMV)
- Clean out all the hydraulic brake pipes using denatured alcohol, or equivalent.
- Dry the brake pipes using non-lubricated, filtered air.
- Repair or replace ALL of the following components listed and install them to the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system:
- Master Cylinder Overhaul or Master Cylinder Replacement; also perform the following: Clean the brake master cylinder reservoir using denatured alcohol, or equivalent, then dry the reservoir using non-lubricated, filtered air. Inspect the reservoir for cracks and/or damage and replace if necessary.
- Replace the brake master cylinder reservoir cap diaphragm.
- Brake Hoses
- Brake Calipers
- Brake Pressure Modulator Valve (BPMV)
- Remove all of the following components listed from the vehicle. Each component contains internal rubber seals/linings which have been contaminated by the contaminated brake fluid in the brake hydraulic system:
- If the brake fluid was not contaminated with an oil-based or a silicone-based substance, but was contaminated with water or dirt, rust, corrosion, and/or brake dust, replace the brake master cylinder reservoir cap diaphragm. The diaphragm may have allowed the moisture or particles to enter the hydraulic system.
- Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11(R), GM U.S. P/N 12377967, or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
- Pressure bleed the hydraulic brake system. Begin the procedure with the pressure bleeder reservoir filled to the maximum-fill level with the correct brake fluid as indicated.