Kinky 6 , make sure the master cylinder you are using is for dics/drum aplication. Sounds as though you have M/C designed for 4 wheel drum system,which contains a residual in the frt. port.Not to cause confusion but floor mounted M/C's in some cases need a very light residual valve to keep a firm pedal, however the factory residual valve is to strong. After changing to a Dics/Drum M/C you may have to install an aftermarket "2 psi"(blue)inline residual valve on the frt.side. May this will help.... Paul
