I had front break work done. Now the front breaks almost lock up intermitently. The break pedal becomes very hard and the front end shakes. Master cylinder has been replaced. The car was brought in because there was an air hissing noise when the break pedal was depressed. They replaced a front caliper, and I have had this problem ever snice. They replaced the master cylinder, a break line and the car still has the problem of the front breaks engaging, smoke coming off of both front wheels. If the car is stopped and re started the problem goes away. Then it will start again (break pedal hard as a rock, front end shaking car stops on its own)
front breaks on 2000 Chrysler 300M
by rich47 in Conklin, NY on February 24, 2009
ANSWER by munkyrench , February 24, 2009
Was the master cylinder replaced to fix this problem or is this a new problem? You should take it back to the shop that worked on the brakes and have them recheck their work!
ANSWER by Visitor , March 13, 2010
From the sound of it to me, is that you may have a leaking vacuum diaphram. No noise should ever be heard when hitting the brake pedal other then mechanical linkages working. It's also possible problem with the vacuum check valve or possibly a kink between the vacuum hose to that goes to the check valve, causing the hard pedal. The vacuum diaphram and the check valve work together to help assist brake pedal effort when you apply pressure on the brake pedal. With out pedal assist you'll get the hard pedal and require greater effort to apply the BRAKES....