74' Plymouth satellite, 318, original front disk/rear drum. I dont have a vacuum pump to properly test my booster, suggestions? and here are my symptoms: 1. Got a whoosh or air hiss at the brake pedal. 2. Master cylinder reservoirs pressurizing when bleeding brakes. 3. At first, rear brakes responded to pumping pedal and bleeding, however in a minute, it looses pressure, pedal goes to floor. 4. When bleeding the front, no lasting pressure happens, pumping the pedal literally feels like pushing fluid back and forth. 5. No obvious fluid leaks anywhere, except m/c lid, yet pedal spongy no matter how much bleeding. No obvious place sucking in air. 6. I noticed passenger front rotor had a moist film of fluid on the face...meaning no pad contact. So, all these components. I aint rich. Dont know where to start. Already bought The wrong proportioning valve. Any input will help.