My 29 year-old master cylinder was shot. I bought TWO rebuild kits, which should've been pretty straightforward to install, and were until keeping the piston/plunger assemble in the bore once the spring was installed. This particular series of master cylinders have no snap ring to hold it all in place. This unit replaces it perfectly and works great. Cost me more than I'd planned on spending, but after fighting with rebuilding the old one, I was grateful this installed without any issues.