The Red October

Took my car over to my Dad's last night and put it on the lift. Rotated the passenger's side rear wheel, and listened to it with a stethescope. Sounded good, just like the driver's side. However, we did notice the other tires were cupped. So that is where my noise is coming from...

As for the dust on the wheel... We came to the conclusion that is it brake dust, just heavier on the driver's side. Then I began to put the pieces together...

1. Last fall, I had a problem with my brake fluid boiling over.
2. Passenger's side rear tire has alot more wear than the other tires.
3. chamfer seemed alittle different on the inner brake pad on the passenger's side rear brake when I took it apart.
4. Alot more brake dust appears on the passenger's side rear wheel.
5. About a couple of times a month, the ABS and ESP warning lights come on when driving. They go off after I restart the car.
6. Last night after driving for a 20 minutes, I felt the rear driver's side caliper, it was warm, and the passenger's side was hot.

Any idea what this could be? Stuck caliper, or something with a bias valve?

diagnosticator1

When the piston is pushed out to apply braking pressure on the pads, the seal ring rotates a little bit in the direction the piston moves out, the inner diameter moving with the piston, the outer diameter staying fixed in the cylinder bore grove.When the brakes are released, the twisted seal ring, pulls the piston back into the caliper as the ring untwists again. This is called piston retraction. If the caliper is for some reason sticking and the piston can't retract, then the pads drag all the time, that is why the brake parts are hot and the pads are wearing a lot on that wheel. A reman replacement caliper assembly is needed to correct this. And as the case may be in your situation the mechanical e-brake parts inside the caliper, that extend the piston when the ebrake cable pulls and rotates the actuator shaft, is also a likely cause of failure of the piston to retract, besides a sticking piston, but the effect is the same, with the same repair of caliper replacment.

The Red October

I have noticed that my Ebrake does not seem to work as well when parked on a steep hill.

Can I buy a rebuild kit for the rear caliper? About how much would that be vs a new caliper?

Any test I can do to positively identify this as the cause?

javanator

* tracks thread *

Bronze

The so called rebuilt caliper looked brand spanking new, and included the carrier also. I thought rebuild kits are mainly just seals, which I'm not sure would address your issue.

diagnosticator1

as the brake pedal is pressed and released. Compare to the other side and front brakes, the fronts will move a bit more than the rear caliper pistons. You can also see or feel the piston moving when the ebrake is set and released. With the wheels off the ground, you can rock the wheel forward and backward a little bit to sense pad contact and release with the rotor. The existence of a seized piston or a stuck ebrake actuator is not obvious in comparison, both defects will cause identical evidence symptoms. In the case of ebrake problems, the action of setting and releasing the brake may feel a bit mushy compared to a proper ebrake system condition, or not. Also make sure the caliper guide pins are free and not seized. The caliper must be able to float sideways on the guide pins, to center align with the rotor when the brakes are applied. Seized guide pins, will wear one pad a lot but the other won't wear much. The rotor will wear on one side more than the other also.

The Red October

Why do I need to replace the whole caliper vs. buying a rebuild kit and rebuilding it?

diagnosticator1

requires more effort. Like "Bronze" says, a re-manufactured assembly is more practical overall, and good used recycle parts are another option.

diagnosticator1

available. For example, if the caliper cylinder bore is corroded and damaged, restoring the bore is not practical being more expensive than a reman or used good part. Plus if the ebrake actuator mechanism is damaged, replacement parts are not easily available.