1999 Dodge Neon brakes seize up

JASONX6000

MEMBER
1999 DODGE NEON
4 CYL
FWD
AUTOMATIC
124,000 MILES

When the car warms up the front brakes will sometimes apply on their own. Meaning, they squeeze on the rotor and I end up driving against the brakes. Ive replace one of the calipers, the pads have been replaced 4 times in a year, as well as rotors. If I stop and shut the car off, then restart, the brakes are so tight, I cant drpress the pedal or move the car, its locked up? I am going to replace hoses to the caliper and both calipers, but other than this, I have no idea. Someone mention something about vacuume? Any suggestions would be awsome. Thanks

1 Reply

CARADIODOC

MECHANIC
33,870 POSTS

First, remove a cap on the master cylinder and look at the rubber seal. If it balloons up and is soft and mushy, the fluid has been contaminated with petroleum products. In that case, all rubber parts must be replaced. The seals in the master cylinder grow and block off the return port, so brake fluid gets trapped and the brakes can't release.

When the brakes lock up again, try loosening the two nuts attaching the master cylinder to the booster. If the car rolls freely, the booster push-rod is mis-adjusted, or more likely, the brake pedal is being held down slightly by a mis-adjusted brake light switch.

If only one front brake is locking, open the bleeder screw to that caliper. If the brake releases, suspect rust buildup inside the metal bracket in the center of the hose. As the rust builds, it pinches off the hose. The high pressure from your foot forces fluid to the caliper, but the fluid will not flow back to the reservoir. As the brake heats up, the trapped fluid expands so the brake applies harder, and the fluid gets hotter. A channel-lock pliers works great to peel the crimp open slightly on the metal bracket.

Caradiodoc