Once, in my ignorant youth (and I only wish the ignorance would
disappear as fast as the youth :)) I swapped in a junkyard brake
master cylinder and drove with it without rebuilding.
The cylinder failed catastrophically in traffic about a month
later. I was very lucky to avoid harm. It is quite possible
that master cylinders "wear in" to a particular car and usage
pattern. Reinstallation into a different car may lead to pre-
mature failure. But this is speculation.
The fact is, you don't know the condition of that m/c, you only
know it's used. I always replace hydraulic components with new
ones, except for disc brake calipers which I have reconditioned.
I doubt very much you'll get much encouragement from this list
to go on with this boneyard m/c, it just isn't worth it. There
are some things you mustn't try to save money on.
- Dan Parslow