I have a 1992 Ford Crown Victoria that has rear disc brakes. This vehicle is a spare one that we use occasionally. I had driven it about 30 miles and as I was parking it at the house. I put it in reverse to back it where I wanted to park it, when it started to barely move when I was backing it. I realized that the rear brakes were locking up. When I removed the rear wheels to check out the problem I didn't see any obvious problem. Given the age of the car I thought it was a good idea to replace all the hydraulics and the pads. The rotors looked OK so I didn't replace them. I installed a new brake hose, remanufactured caliper, and new pads on both rear wheels. So, I thought my rear brake problems would be gone for good. I moved the car to a different spot in the yard and everything went OK.


The next time I was going to use the car I drove it to the gas station for fuel and to clean the windshield. I barely made the one mile trip back to the house as the rear brakes had locked up again. I thought that the car might have a center, rear brake line that was collapsing inside the hose and keeping hydraulic pressure from being released from the rear corners. But..... when I got under the car to look for a center, rear brake line I found none. The left, rear brake hose has an inlet and an outlet on the end opposite the caliper, which receives the brake line coming from the front of the car and also an outlet which provides fluid to the brake line that runs from the left, rear corner to the right, rear corner. So, basically I'm explaining that the left, rear brake hose serves the function that the center, rear one would for a vehicle that has three rear brake hoses.

I looked online to see if this car has a proportioning valve that may be the problem, but I couldn't find one. I didn't really think that the master cylinder could cause such a problem, but maybe I'm wrong. If the master cylinder was the problem shouldn't it make the front brakes lock up as well?

Has anyone ever experienced anything like this or have any suggestions on how I should proceed to diagnose the problem? I would prefer to diagnose it instead of just throwing a master cylinder at it to see if that corrects the problem. Any help would be appreciated.

 

Did you attempt to open the bleeders to see if there was any pressure being held at the calipers?

 

No sir, I have not. I was advised to check the parking brakes and cables first. If that doesn't help, then I'll try your suggestion. Thanks!