Cadillac Repair: 1991 DeVille brakes REAL soft, caliper pistons, wheel cylinder
QuestionI have a 1991 DeVille, I just changed the front brake pads. Since then, the brakes are really really soft. I can go almost all the way to the floor before they start to really grab. I'm sure the rotors need to be changed too, but I've never seen brakes do this just after changing them, bad rotors or not. I'm not sure what else to check or do here. Any help would be awesome. Thanks.
Jeff
AnswerHi Jeff,
The way you describe the brake pedal and what you did doesn't make any sense why the pedal went soft. If all you did was push in the caliper pistons and install new pads then the pedal should be ok after pumping the brake pedal 5-6 times. It takes that long for the piston to move out and make the pads touch the rotors. If you push 10 pumps and the pedal is still soft then there has to he a coincidence that happened like a wheel cylinder blew out, a brake line or hose sprung a leak or the master cylinder is leaking internally and needs to be replaced.
At this point what I would do is push the brake pedal 10 times and then hold it while you see that both caliper pistons are moving out. Then look under the car to make sure there isn't any brake fluid on the ground. And check the master cylinder to make sure the fluid level is ok. Bleeding the brakes would be next. Start at the RR, LR, RF and then LF and make sure that fluid comes out in a steady stream and not have any air. Another thing to isolate a low pedal is to have all the tires off the ground or one at a time and push the brake pedal and see if the tire turns. Then you know what brakes aren't working. The last thing is to pinch off a brake hose with a needlenose vice grip and then see if the pedal returns to normal. Maybe a wheel cylinder is frozen and not moving.
Try those things and see what happens. If unsure how to do any of the tests have your car towed to your mechanic and have it diagnosed and repaired. Let me know what happens if you need anymore help. Bill
