Hydraulic Brake System Flushing
WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Refer to Brake Fluid Irritant Warning .
CAUTION:
Refer to Brake Fluid Effects on Paint and Electrical Components Caution .
- Inspect the brake fluid for the following conditions, indicating brake fluid contamination:
- Fluid separation, indicating 2 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 and/or brake dust
- Fluid separation, indicating 2 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.
Refer to the procedures indicated:
- Master Cylinder Replacement
- Front Brake Hose Replacement
- Rear Brake Hose Replacement (Drum Brake) Rear Brake Hose Replacement (Disc Brake)
- Front Brake Caliper Replacement
- Rear Brake Caliper Replacement , if equipped
- Rear Brake Cylinder Replacement , if equipped
- Brake Proportion Valve Replacement , if equipped
- Brake Pressure Modulator Valve Replacement , if equipped
- Clean out all the hydraulic brake pipes using denatured alcohol.
- 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.
Refer to the procedures indicated:
- Master Cylinder Replacement ; also perform the following:
- Clean the brake master cylinder reservoir using denatured alcohol, then dry the reservoir using non-lubricated, filtered air. Inspect the reservoir for cracks and/or damage and replace if necessary. Refer to Master Cylinder Reservoir Replacement .
- Front Brake Hose Replacement
- Rear Brake Hose Replacement (Drum Brake) Rear Brake Hose Replacement (Disc Brake)
- Front Brake Caliper Replacement
- Rear Brake Caliper Replacement , if equipped
- Rear Brake Cylinder Replacement , if equipped
- Brake Proportion Valve Replacement , if equipped
- Brake Pressure Modulator Valve Replacement , if equipped
- 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 which may have allowed the moisture or particles to enter the hydraulic system.
- Fill the brake master cylinder reservoir to the maximum-fill level with GM approved 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. Refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Pressure) .