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Old 07-02-2011, 11:07 PM
woodrat woodrat is offline
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Join Date: May 2006
Location: SW Washington State
Posts: 119
Quote:
Originally Posted by sixto View Post
What I read is the column of fluid at the far end of the master cylinder doesn't circulate well since you don't push the pedal to the floor on any regular basis. Moisture in that blob of fluid corrodes the master cylinder bore. it only becomes a problem when the pedal goes to the floor such as when bleeding. The piston seal slides over and is damaged by the corroded section of bore. I don't know that this should necessarily cause fluid to leak into the booster. Seems it will act more like a worn shock absorber with no external leaks. Of course a master cylinder can leak from the actuator end into the brake booster. Would that go into the vacuum side of the booster?

Sixto
87 300D
My master cylinder was old and crudded up like this, and it had no external leaking going on, just cruddy, wet, old fluid sloshing around inside, leaking past the seals and not doing any useful work.

And yes, if it leaked out through the back of the MC into the booster, it would be leaking into the side of the booster with vacuum on it.
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