# brake master cylinder leaks



## Asura (Aug 27, 2004)

my brake master cylinder has been leaking from the reservoir cover so far. At first I suspected bad seal in the cover, so on went a new cover, the same thing repeats itself. So then I suspect the master itself is bad. Put in a brand new master (Tokico), same thing repeats, leaks from under the cover after several hard braking.

any clue? have bled the brakes thrice so far.

also, I noted that the rubber seal for the output rod from the brake booster seems to be blown, could that be the source? Vaccum tested the booster and it holds it just fine.


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## tantan12 (Nov 2, 2009)

did you clean the booster before installing? and an external brake fluid leak could be possible. the master cylinder usually has a plastic reservoir that holds the brake fluid. The grommets allow for some movement caused by brake pedal and fluid pressures. These grommets can leak fluid, and a visible brake fluid leak can be seen with the naked eye. i believe changing the master cylinder cover won't solve the issue


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