Leaking Master Cylinder Cap

[pltmgr]

The rebuilt master cylinder I recently installed was leaking from the cap. The gasket was new and the clamp was tight but the sealing surface was nicked and actually somewhat irregular. I wasn't keen on returning it to the place of purchase, waiting, and running the risk of the new one doing the same so I tried this tip found on another forum. I placed the mc upside down on piece of sandpaper and used a circular motion until the sealing surface was true. No more leaking.

[cdeal28078]

I was at the pull a part anyway and just grabbed another gasket form a truck. I added it to the gasket already under the cap on mine and it fixed my problem
clint

[fordman]

you have a clog in the brake system i would say. the fluid usually doesnt leak out unless there is pressure being built up inside the fluid bowls and forcing it up and out of the master.

[cdeal28078]

It did on mine. The rebuilt master cylinders are not perfect around the top lip where the gasket seals. The single gasket is not soft enough to fill the voids so with the rocking of the truck fluid will leak out and keep the outside wet. Mine was not dripping and leaving puddles just keeping the paint bubbling on the master cylinder
clint