Hello Everybody! Hope you can help me!

Over the weekend I put a new rear axle in my '85 745 V8. (yes, I blew up another rear end) In the process I managed to break my brakes. There was nothing about the change which should have caused me a problem. I used the calipers and rotors from the old axle. I didn't open the system or anything.

My problem started when I was attempting to break my driveshaft loose. I decided to start the car, put it in gear and have the engine torque the driveshaft off the pinion flange. (done it a few times before... this junction always causes me problems) Anyway, this time I forgot that I had removed the calipers and rotors from the axle. So, I started the car with my foot on the brake and the pedal went to the floor.

I realized that I had just forced the rear pads together on both sets of calipers. Hoping for the best I pressed the pistons back to the needed position. Later that day I had the whole rear end back together. Drove the car but the right rear rotor wasn't flat (burr on the axle) so I got a pulsing brake. I pulled off the rotor and fixed the axle problem. When I had the caliper off I needed to move the pads a little farther apart so I got a screwdriver and stuck it between the pads and twisted. The pads moved more rapidly than I thought and were driven back to the face of the caliper. When I started the car the brake pedal went to the floor (slowly) and the brake light came on in the dash.

I removed the distribution block switch and put it back. (light went out) Brakes were still soft.

I noticed the right rear caliper was no longer moving. The pistons were not pressing the pads to the rotor.

I decided to bleed the brakes, thinking I might have caused a problem. No effect. I did get fluid (2 years old) out of all the calipers with no problem.

I then took off the right rear caliper and removed the pistons. They looked clean, though one seemed to be much harder to remove than the other. (these were rebuild calipers ~5 years ago & 30k miles) Bleed the whole system again. No luck. The pedal is soft and goes to the floor. Though, the brake light hasn't come on again. I might have messed up the switch when I put it back together.

Soooo, I decided that all of this pedal to the floor business had messed up my master cylinder. (5 years, 30k miles old) Just replaced that. No change.

I'm kinda out of ideas. The rubber lines are IPD SS lines, 5 years and 30k miles old. I've modified my system for a Jumbo upgrade. Right now I have two lines blocked from the MC. I'm running a right front/left rear and left front/right rear diagonal distribution. When I drive, I do get some brakes, but the car pulls very hard to the right. Makes me think that my whole right rear, left front diagonal isn't getting pressurized. When I pressure bleed I get flow (similar rates) through all of the calipers.

Anybody have any thoughts? I haven't noticed, but does the car have an independent proportioning valve for each of the rear wheels? Could I have messed up the RR proportioning valve in such a way that I get fluid flow but no pressure to the RR caliper?

Thanks for any thoughts!
-simon