Need some advice. I was driving down a hill pressed the brake pedal down and it stayed down. Replaced the booster last year so I thought it was the master cylinder, it's 15+ years old. Bench bled and installed new master cylinder. However it won't build up pressure? I opened the bleeder on the passenger caliber and fluid barely comes out. Pedal still "Dangles", no pressure at all just goes to the floor. I see two proportional valves along the frame that the hard lines from the Master cylinder go into. Could they both or one of them be bad? Thanks! TC