1989 Ford Bronco V8 Four Wheel Drive Automatic 142456 miles
Hi, I had to perform a Brake job on my Bronco XLT 4DR. After bleading the brakes, I test drove it and the brakes were spoungy. I then replaced tha Master Cylinder. The Rear brakes then began locking up. I have retraced my steps disconnected the vaccuum hose from the power booster, they still locked up. I disconnected the RABS system and they still locked up. I then, while they were locked unhooked the rear line from the proportioning valve and the brakes imediately unlocked. I have come to three choices but I would like to hear from you. Is it possible that the new Master Cylinder, Proportioning Valve, or the RABS system is causing this problem when I did not have the problem prior to replacing the Master Cylinder? Which one would you choose to pursue first?