My master cylinder is leaking, I hate to have to spend all that money on a rebuild kit I can't need anything more than an o-ring? Is it possible to fix with out the rebuild kit? Anybody ever remove the C clip and pull it apart and just replace the o-ring?? I need a cheap quick fix
$65 the last time I bought one. [rebuild kit] A master cylinder is upwards of $350. No cheap fix there. Often they become pitted in the bore, and have to be resleeved to be rebuilt.
It appears your mastercylinder is fine. Does it work properly? Normally, when they leak (and are malfunctioning) you'll see rust and crud around the piston. Yours doesn't have that, instead it's rusty on top which tells me the reservoir o-ring is bad. It seals the reservoir to the body of the mastercylinder.
The bike had been sitting for over 5 years. Now I'm tring to get her back on the road. The mastercylinder was bone dry. I filled the sytem and bleed the brakes. They now work but fluid is comming out around the piston bore for sure. I guess I'll be getting the rebuild kit.
The piston normally doesn't travel the full length of the bore, except when the brakes are being bled. In the unused untraveled portion some corrosion or gunk can build up, then when the piston is forced into that section, the seal gets compromised. Rebuilding is a good way to go, and if it's badly pitted in the normal travel area, it can be re-sleeved for much less than new. Once re-sleeved it should be good for another 30 years at least.
+1.... and your life could depend on that $65.00 rebuild kit. I cleaned up my master cylinder prior to rebuilding with some very fine crocus cloth as it was not pitted, but had some surface crud in the bore in the untraveled portion. Works fine.
Handy tip: I wound that putting the end of a .22 cleaning kit on a drill and using fine emory cloth I could give master cylinders a good hone to clean them up.
