1999 Chevy Truck V8 Two Wheel Drive Automatic
99 chevy 3500 dually 5.7L with hydro- boost. The master cylinder was leaking so I replaced it now I have spongy brakes. Truck stops O.K. But no resistance in peddle until close to floor. Bench bleed m/c installed, bleed all lines starting from furthest from m/c. Problem started so I isolated the rear brakes by removing the front line from m/c and capped. Bleed rear brakes good stiff peddle reconnect front line and bleed the front peddle gets spongy again checked lines and calipers for leaks none found disconnected rear brake line from m/c and capped never gets stiff in front flushed lines with new DOT3 no improvement also p/s pump leaks could that affect the hydro-boost.