rebuild or replace

[Sierra John]

My brake pedal is soft and sinks almost all the way to the floor. I'm thinking the master cylinder is the problem. Also, brake fluid is leaking from under the rim of the reservoir cap. I just had the rear end refreshed (new drums, shoes, wheel cylinders, etc.)--don't know if that's related or not. I've read some negative things about the quality of new master cylinders. Would you replace the unit or buy a rebuild kit? What's your opinion?

[Alan H. Tast]

Go one step further: Send an original out to be bored-sleeved back to OEM specs and rebuild. I've done that with several master cylinders and will do same for wheel cylinders. Search old posts for resleeved MCs.

[64ZCODE]

Try bleeding the brakes and see if that improves the pedal action. And check to make sure the cap on the reservoir is sealing; under normal operation, brake fluid surges back into the reservoir and if it is leaking out of the cap, the seal is probably bad or the cap isn't tight.

[Sierra John]

Thanks for the replies. I put a new gasket under the reservoir lid. It made no difference. The brakes got bled a week or so ago when I had new rear brake cylinders installed.