Draining master cylinder


May 18, 2020

Draining master cylinder​

I had to pull the proportioning valve / combination valve out of a car. ( Everything was nicely painted) Needless to say this was a messy job. I know I will never get it back in without making a huge mess and brake fluid running all over the place. If I allow the master cylinder to drain but don't press the pedal will I need to bench bleed it again? I think I did this years ago and since I didn't touch the pedal I was fine. Thanks in advance I appreciate it


Supporting Member
Mar 12, 2010
Houston, TX
If the master cylinder is drained dry, you will most likely have to bench bleed it again since air may stay trapped inside the cylinder because of the angle of the firewall tilts the front of the master cylinder up.


Mar 31, 2006
Kitchener, Ontario
you will need to bench bleed it....if you don't want to removed the master you can use this method...


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