Left front brake caliper will not release completely

WADEBOB

MEMBER
2010 MINI COOPER S
1.6L
4 CYL
2WD
MANUAL
80,000 MILES

I have an issue with the left front caliper dragging. I have replaced the front calipers, rotors, pads, brake lines and master cylinder. The driver side front caliper still has a slight drag that causes the car to pull to the left after a short drive. The car has a ABC/DSC module but no warning lights.I have done a pedal test for the brake booster which seems to be working fine. Engine performance seems a bit down, but I contribute this to the brake not releasing completely. Stopping is in a straight line little or no drag effect. The only issue I did find was the brake pipe fitting on the caliper side to the left front was stuck. I have ordered a new pipe. Could the problem be with the ABS unit?

1 Reply

STEVE W.

MECHANIC
13,573 POSTS

Hello and welcome to 2CarPros.

It sounds like you could have a bad brake line or a blockage in it to the caliper. The inside can fail and act like a one way valve or a piece of crud can get in and act the same way. You apply the brake and it doesn't release fully. Then as the pad rubs it heats up the caliper and fluid until it applies with more force. An easy way to test if this is the cause. Get it to act up, then jack it up a bit and release the brake bleeder. If that releases the brake then try flushing that line back to the fitting you had a problem with.