Operation CHARM: Car repair manuals for everyone.

System Flushing


Hydraulic Brake System Flushing

In order to flush the brake hydraulic system, run new brake fluid through the brake system. Continue until the brake fluid at each bleeder valve comes out clear. Flushing is the only way to clean contaminated fluid out of the system. Flush the brake hydraulic system for the following reasons:
- New hydraulic brake parts are installed
- Contamination may be present
- You do not know the grade of brake fluid in the brake system
- Mineral oil is present in the brake fluid

Important: Flush the hydraulic brake system at each bleeder valve.

1. Open the bleeder valve 1 1/2 turns.
2. Force the brake fluid through the pipes, hoses, and bleeder valves until the brake fluid comes out clear in color. Refer to Manual Bleeding or Pressure Bleeding.

Important: Inspect the master cylinder fluid level after you flush at each bleeder valve.

3. Refill the master cylinder as required.
4. After you flush the hydraulic brake system at each bleeder valve, fill the master cylinder to the correct fluid level. Refer to Brakes; Service and Repair; Master Cylinder Reservoir Filling.