Find out if fronts or rears are holding/actually braking. See if one is not. Residual valves needed for shoes, usually not for pads. If you told CPP you had rear drum and front disc, they would have sent the correct parts to you or advised what you needed. Proportioning valve, residual valves, bleeding instructions, etc. Never had a problem with installing front disc from CPP. Spongy=air=leak, need to vacuum bleed or wrong components.
