The brake failure light on my '87 760 TI came on one day. Just in the middle of driving, it flashed on, and was on and off intermittently, but the brakes functioned properly. (The anti-lock light was on as well, but has been for a long time.)

One day, I was driving, and noticed that the brake failure light was actually off, so I naturally thought whatever the problem was had worked itself out (or the bulb died). But then when I tried to brake going about 60MPH, the car pulled hard to the right, and the pedal didn't depress smoothly. I drove carefully to the nearest place I could pull over; turned the car off for a quick visual inspection including fluid level (all fine), started the car and the brake failure light was on again--and the brakes behaved perfectly.

I have since had the front rotors ground (there was pulsing anyway), replaced the aftermarket wheels that came with the car with some wheels that came off of a Volvo I had before, replaced the pads, and bled all four cylinders of the front brakes. Once I got it all put back together, the brakes worked nicely, and so did the anti-lock system. But after a little driving, the brake failure light came on again, and so did the anti-lock failure. Things are back as they were--if the brake failure light doesn't come on, it means it's going to pull hard to the right if I brake at over 50 or 55 MPH.

Not sure where to go from here. Any advice is appreciated.

vm

PS: Oh, I should mention that one of the rubber billows on the front left caliper is missing, but when I had everything taken apart, the pistons moved freely. Should I replace that billows? If so, where can I get another one?