Operation CHARM: Car repair manuals for everyone.

Master Cylinder Bleeding

1. Support the master cylinder body in a vise, and fill both fluid reservoirs with heavy duty DOT 3 brake fluid.
2. Install plugs in the front and rear brake outlet ports. Bleed the front brake outlet system first.
3. Loosen the plug in the front brake outlet port. Depress the secondary piston slowly to force the air out of the master cylinder. Tighten plug while piston is depressed or air will enter the master cylinder.
4. Repeat this procedure until air ceases to exit at the outlet port.
5. Repeat steps 3 and 4 for the rear brake outlet port with the front brake outlet plugged.
6. Tighten the plugs and try to depress the piston. Depressing the piston should be harder after all air is expelled.
7. Install the plastic cap.
8. Install the master cylinder in the vehicle and bleed the hydraulic system.

For additional information see Bench Bleeding.