When I bought the car I'm working on, the guy who sold me it said the master cylinder was leaking (I said "whatever", but that's really important now). My worry is that I cannot repair this one and may have to buy a new one. Is this true? Based on the paint corrosion, I assume it is leaking from the point where the master cylinder meets the booster. Is there a gasket in there that can be replaced? Any other places that I should look at to stop a potential leak?
BTW, the master cylinder isn't on the car now (See sig), so I can't test it by conventional means. Perhaps there's a way to test it some other way, but I don't know it.

 

Replace it. You could try to rebuild it, but if you just get a reman master then you get that wonder of wonders - a WARRANTY.

 

You can download the microfiche blowups at
http://www.mazdaformance.com/rx7.htm

You can order rebuild kits or a new master cylinder from
http://www.mazdatrix.com/j-3brake.htm

-John.