1992 With Poor Brakes

['90 Escort Man]

I am trying to fix a poor brake pedal condition on a 1992 LeSabre with 170,000 miles on it. Sometimes have full pedal, but mostly little to none. Both calipers and brake cylinders are dry, no leaks. Brake lines rusty, but intact. Bled the lines starting from furthest to closest at 3 pressure releases, then started over at 3 more, then finally 5. Used a whole large bottle of fluid+. No improvement. Replaced master cylinder, bled master cylinder, then system. Have consistantly low pedal pressure now (improvement?). Can I hot wire the ABS motor to bleed the ABS controller and brake lines? I think I have air somewhere in that mysterious ABS controller.

[3echo9]

That is interesting. Today I lost all pedal resistance. Just sitting at a stop sign the pedal just sank to the floor. No leaks that I can see and the MC resivoir is full. Do you know how to test for a bad MC versus the ABS motor? Mine is a 92 Lesabre as well with 120k. My lines are rusty but seem to be holding as well.

['90 Escort Man]

I don't have the foggiest of testing the ABS controller. This car that I have had the misfortune (not knocking Buick, this is a well built car) of repairing also has the ABS light on. I am going to check the library for a repair manual. I am a step below a shade tree mechanic, so if I find something, I will post again. I hope to here from an expert on this controller thing.