Bench Bleeding Master Cylinder
NOTE:
Bleed tubes must have a residual pressure check valve installed to keep tubes from siphoning brake fluid.
- Master cylinder must be bled before bleeding entire system. Master cylinder bleeding may be done on vehicle. Preferred method is to bleed master cylinder on bench. If master cylinder has a bleed screw, bench method should still be used. When master cylinder is installed on car, use bleed screw as a final check for trapped air.
- Place master cylinder level in a vise. Attach bleeding tubes to cylinder. Fill reservoirs with fluid so that ends of tubes are covered as shown in Fig 1 . Tubes attached to disc brake outlets must have residual pressure valves installed over ends. This will keep tubes from siphoning.
- Stroke piston in bore with a wooden stick or dowel until bubbles no longer appear at ends of tubes. Remove tubes and plug the master cylinder disc brake outlets to keep fluid from draining.