Rebuild kit for the tandem master cylinders (GMC173/GMC195/GMC198/GMC192). Used from 1979 to 1985, these masters had multiple little differences, and are no longer reproduced. This rebuild kit will work on all of them provided the piston and bore is in ok condition. They were eventually replaced with the yellow band dual line master cylinder (GMC227), which can be retrofitted in place of the previous master cylinders by using a brake line adapter kit. (BAU5655MS for LHD, BAU5654MS for RHD.)