my son has a 1985 lebaron and the brakes just suddenly stopped working. he has replaced the pads, rotors, calipers and bled the system but when you push the brake pedal it goes to the floor. the mechanic where is works is stumped - been like this for three days and they can’t figure out what the problem is. can someone help - the boy needs a car and mom needs him to have a car! thanks
It has to still have air in the system or a bad master cylinder.
Thanks - I think he replaced the master cylinder too
Not all master cylinders are built right in the aftermarket. If no fluid is pushing through the master cylinder, easy to check with a bench bleed kit, the master cylinder is bad. Some aftermarket master cylinders I’ve had go bad within days of installing.
It could have a stuck proportioning valve. This sometimes happens if air is introduced into the system or the brakes are not bled properly. Sometimes a swift kick to the brake pedal will pop it back into the proper position and allow the brakes to be bled. To try that trick, with the bleeders closed and the master cylinder full, give the brake pedal a swift, hard jab with your foot. Not a full-on stomp, just a quick stab, as hard as you can. This trick can be repeated, as it sometimes doesn’t work the first time, but sometimes it doesn’t work at all. It’s worth a shot.
Another thought is that there could be a problem in the rear as well. If a wheel cylinder back there is frozen up, the brakes will never get properly bled. The rears have to be bled too, and have to be fully functional for the brakes to work at all.
thanks everyone for your help. turns out that the rebuilt master cylinder was bad and they had to put it on a pressure bleeder to get all of the air out of the lines. got it back today and it seems to be fine.
Thanks for letting us know the outcome. Many people never come back to tell us what happened or how the problem was resolved, and many of us like to know.