losing brake fluid but....

[minimike]

I've gone out to the car and found no brakes and no fluid in the master. I have brakes at the bottom of the pedal once the m/c
was refilled, and have yet to bleed the system due to broken bleed nipples. No fluid loss under the car. No fluid leaking at hoses or leaking calipers, no fluid in the booster vac hose, so I assume no fluid going into the booster. No fluid on the back of the brake pedal itself inside the car.

any clues before I bleed it out? I've just swapped out the rear calipers for a pair I rebuilt a while back, so It surely needs a bleed, but this was all done after I discovered an empty brake m/c. I don't see any peeling paint in the engine compartment from leaked brake fluid. I'm stumpped. Losing the full contents of the m/c is a lot of fluid and has to go somewhere. I saw no fluid trail on the insides of the tires, and when pumping the brakes with the car on jack stands, wheels off, no sign of fluid
pissing out anywhere!


Ideas?????

[So Cal Mark]

probably going into the booster. I've never seen fluid in a vacuum hose, even when the booster was nearly full of fluid

[minimike]

I see the rebuild kits for the 2.O spiders are NLA. I'm gonna guess a split diaphram.

Does it make sense to drill the can and suck the fluid out so I don't spill it all over the paint?

I'm guessing I'm gonna have to replace the booster.

[mgbgtn]

The problem is not the booster but the master cylinder that is leaking. If the cylinder bore is ok, you might get away with a rebuild kit or depending on cost, just replace the master cyl. Don't put a hole in the booster or you will have to replace it as well. Just take it off and tip it on end to drain it.

[So Cal Mark]

fluid in the booster will eventually cause it to fail. Remove the mc mounting bolts and just slide it fwd to check for wetness

[minimike]

I"ve found a spare in my garage, booster and m/c. I've read that the rear seal on the m/c is what lets the fluid weep or pour into the booster.
Marc, you've mentioned that fluid in the booster will eventually cause it to fail. Are they not all rubber bits in the booster? Can I flush the booster with a detergent or something to clean it out?, or should I dis assemble it and wipe down the internals?

mike

[dmwhiteoak]

[ should I dis assemble it and wipe down the internals?]

Easier said than done. Good luck

[narfire]

[quote="dmwhiteoak"]Easier said than done. Good luck


I'll second that. Just removing from the fire wall is a fiddly job. You have to do the deaded under dash contortions..