Master cylinder question

[todras]

Ok I'm helping another CEGer fix a MC/booster leak. It's leaking where the MC enters the booster.

What causes this? I pulled the MC out of my parts car to see what could be leaking on his. Thought there might be an o-ring back there but it's just metal. Do we need to do the booster as well to stop the leak?:help: I can put the MC I have in his but will it leak? How is removal of the booster? Looks painful but haven't studied it too much.

 

[Rara]

Replace the master cylinder. There is no fluid seal between the master cylinder and booster. The booster only holds air; the master cylinder has an internal rear seal that retains fluid.

 

[Rara]

Also, I'm not sure which rubber materials are used inside the contour brake booster, but there is a possibility that brake fluid contamination will damage the internal rubber diaphragm. once you have it back together, check the feel on the brake pedal, with the engine running. If it feels overly firm, the booster may have an internal leak. If that is the case, replace the booster as well. it should not be too difficult to replace once the master cylinder is off. Disconnect the vacuum line to the booster, then go inside the car, under the dash and disconnect the booster input rod from the brake pedal. I don't recall which attachment method the contour uses, but it's probably a ring with a clip to retain it. Either way, it should be pretty obvious how to unhook it once you look at it. Then there should be 4 nuts that attach the booster to the brake pedal box. (There might be 2, it's been so long since I've been under the dash on a contour) undo these nuts and the booster should be loose and you can remove it on the engine compartment side. IIRC there is a pretty big standoff bracket on the booster to the dash panel.

It should be pretty simple, aside from the gymnastics necessary to get under the dash to see . . .

 

[todras]

Sounds like a plan Stan!