engine and drivetrain Brake Fluid Spraying Out The Back Of The Brake Booster

[thehackmechanic]

I have a good-sized a brake fluid leak in a customer's 2002, leaving puddles and visibly draining the reservoir. I crawled beneath it and had someone pump the pedal while the engine was running with me I looking up, trying not to get brake fluid in my face. When the pedal is pumped, I'm seeing a spray of brake fluid out the back of the brake booster, where the linkage goes in. I am I correct that this is probably a bad seal between the master and the booster, and that the master probably needs to be changed but the booster itself is probably okay?

 

--Rob

[M3M3]

Time for a new master.

And a new booster. There must be a lot of brake fluid in it.

[chargin]

That sounds like a bad Brake Master has been blowing fluid back into the Booster causing the vacuum diaphragm to rupture. In other words the Booster should now be DOA......

[Mike Self]

+2...rear seal on the M/C has "turned up its toes" and is peeing into the brake booster.  You might be able to salvage the booster by removing it, draining out all the accumulated fluid and then seeing if it'll hold a vacuum.  However, the fact that fluid is coming out the back side of the booster (the firewall side) indicates that the diaphragm has a hole in it.  

 

Somewhere in the archives there's info on one or more places that rebuild boosters...

 

cheers

mike

[TobyB]

I've drained out a few boosters, and they've all survived the process.

 

I can't imagine why the car's not puking a ton of white smoke... if the vacuum's hooked up.

 

Maybe the booster's already dead!

 

t

[jimk]

I think a std yearly PM is in order to use a piece of wire and clean out the inter seal bleed hole on the bottom of the MC so the fluid, if the MC begins to leak, squirts out the vent rather than pushing into the booster.  That's what the vent is there for.