1985 745t

For the last few months my brick has a variety of brake issues; pulling, squealing, etc. Recently I decided to get the rotors and pads replaced and have my indy guy go over the calipers. However, post work I'm still having issues with the car pulling to the left when the brakes are applied.

The car pulls to the left intermittently when the brakes are applied, and it does so with varying severity; sometimes it pulls somewhat hard, other times its only slight.

In addition the brakes are sometimes REALLY hard to use; almost like the pedal is frozen in place or a piece of steel has gotten between the pads and the rotor. I originally thought this hard pedal problem was a factor of the bad rotors, worn pads, or frozen caliper, but its still happening after they were overhauled. When this happens it will often go away if I back off the brakes for a second and reapply pressure to the pedal.

One more thing that may or may not be related; from time to time the wheel starts shuddering, apparently without rhyme or reason. The shuddering and vibration varies in severity, and can get pretty awful. It will usually go away as easily as it appears. When it happens it is usually when brakes are applied or not applied. Again, I had thought it was related to the parts previously mentioned, but its still happening post-fix.

Is it possible I have a bad brake booster, and that it is failing intermittently and causing the freezing (no help, etc.)? Maybe its bad on a side or something and is causing the pulling? The booster, etc., looks fine (no fluid leaking or anything, no sign of damage), but I don't really know if a failing booster would provide a visible clue.

I should note that in the past six months or so I've replaced the ball joints, replaced the sway bar bushings, checked the other suspension bushings (good), etc., so I don't think its the suspension (although the right front tower joint top thing is bad and pops when going over bumps on sharp turns). The brake fluid is dot4+ (should be more than adequate), and is kept topped off.

Thanks in advance for any help.

-rt