Brake fluid leak from master cylinder?

[dragrdan]

I have a brake fluid leak that seems like it is coming from the top of the master cylinder(between the master, and the lid). The master is a just installed reman. The old master was leaking out the rear of it, although I am not sure it wasn't also leaking out the top.
Has anyone else ever run into this? Any ideas or cures?
Thanks

[Richie O]

Is the rubber seal frigged up?

[dragrdan]

No, the one on the old master seemed a little hard, but the new one is like new

[redneckroot]

how hard is it getting clamped down by that wire clamp thing?

[dragrdan]

Pretty tight, can't just pull it off by hand, gotta pry it off. This is a new one to me, and I've spent 20 yrs wrenchin for a living, with most of it spent at muffler and brake specialty shops.

[PToombs]

Mine leaks around the rubber seal too. I turned it upside down and it didn't leak for 6 or 7 months. Now I need to replace it. I also put some fine emery paper on a 2x4 block and sanded the top of the master a little to smooth it off. Original master cylinder.

[Richie O]

My 93 leaks a little. Maybe when they rebuilt the m/c they machined the surface not so true.

[dragrdan]

Well, ended up re-replacing the master, and so far, so good. Will be keeping an eye on it tho. A little bit of seepage wouldn't have bothered me too much, but I lost about 3/4 of the fluid from the master in 3 days

BTW Pete, I like your idea of "lapping" the surface, but how did you keep the metal and emery dust out of the fluid, and master?

[PToombs]

I soaked out most of the fluid and stuffed a rag in there, then picked it out carefully.

[TWorline]

There is something you can try, cut a shim or two from a milk jug and place it between the lid and the gasket. That should give you enough pressure to seal up the lid. I notice from alot of 1st. Gen pictures that the gaskets are leaking on the MC weather they are the original or replacements.