Passenger side front wheel is dragging

JOHN MCLAREN2

MEMBER
2003 TOYOTA COROLLA
1.6L
4 CYL
2WD
AUTOMATIC
238,000 MILES

I replaced passenger side front rotor, caliper, rubber brake line, and the proportion valve and the problem is that it still the same. That wheel and only that wheel is still dragging. Cannot push caliper piston back in without cracking open bleeder valve which the caliper then will release. Please I am stumped.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

The clue you found is the caliper releases when opening the bleeder screw. That proves brake fluid is being trapped and cannot release. The rubber flex hose was a good suspect, but since that has been replaced already, open the hydraulic system at other places to determine where the fluid is being blocked. A convenient place might be right at the master cylinder. If loosening a steel line there lets the brake release, I would suspect the fluid was contaminated with a petroleum product. That will cause all the rubber parts to swell and become mushy. The rubber lip seals in the master cylinder will grow past the fluid return ports and block them.

Another potential cause is a brake light switch that is out-of-adjustment. If it holds the brake pedal down just a little too much, those fluid return ports will be blocked.