Master cylinder was leaking fluid into booster

DAVIDGTI

MEMBER
1983 VOLKSWAGEN GTI
160,000 MILES

Master cylinder was leaking fluid into booster. I fitted new master cylinder and drained the brake fluid from the booster. With the new master cylinder fitted the brakes lock on badly after a few applications. If I disconnect the vacum hose (I have block off the hose) the brakes release but I have no assistance. Is there any option other than replacing the booster.

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2 Replies

DOCHAGERTY

MECHANIC
9,601 POSTS

Rebuilding the booster would be an option, it might be just as costly though. The brake fluid has damaged the booster and replacement is probably the only solution for this issue.

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Thursday, October 25th, 2012 AT 5:21 AM

EXOVCDS

MECHANIC
1,883 POSTS

Do you have the correct amount of free-play in the brake pedal?

If the pistons in the master cylinder are not able to return fully, pressure will build-up in the lines because fluid can not return into the reservoir.

Adjust the booster rod "tip" that pushes against the master cylinder to get the correct amount of free play.

Thomas