I have a 2011 Chevy Impala. I replaced the hub bearing assembly on the rear wheel and as I was replacing it, I noticed the rotor on the left-rear side was dragging. As I turned the wheel, the rotor would drag, then be free, then drag again. Naturally I figured it was either the hub bearing that I was already replacing or the rotor itself being warped. After finishing the bearing job, I noticed the same problem, so, I went ahead and replaced the rotor. To my disappointment, that also didn’t solve the problem. It was the exact same behavior. As I was turning the rotor, I could see it move in and out relative to the caliper bracket as if this new rotor, too, was warped, but I find it hard to believe I’d get a brand new rotor that was warped in the same way.
What else could possibly be causing this problem? I’ve tried searching online, and all the stuff I’m seeing is about warped rotors and bad hub bearing assemblies, but seeing they’re brand new and the problem existed before, I think I can rule that out. I figure if the caliper were out of alignment or the whole wheel was out of alignment, the dragging would be constant and not only on part of the rotation.
Try cleaning all the dirt and rust off the surface the rotor mounts on. If that doesn’t do it you have a warped rotor or bent hub or axle.
Another thought is a kinked line or damaged hose. There is a lot more pressure pushing the fluid out to the caliper then pushing it back, so any obstruction to fluid flow can lead to brake drag. Old hoses sometimes disintegrate internally and plug up the hose or line, but I would not expect that on an 8 year-old car.
Axle might be the best possibility. Seeing that I have a new rotor and hub.
I can see the wobble even without the caliper on, though. If I put the lug nuts on against the rotor to keep it in place and spin the wheel, there’s definitely a noticeable wobble, even though the hub and rotor are brand new. If the problem started after installing the two parts, I’d conclude that either one would have to be defective, but seeing that the problem was preexisting before the installation, either I’m supremely unlucky enough to have a new part with the same problem as the old worn part (something I guess I can’t necessarily rule out, I admit) or something else is amiss.
I have installed new rotors that required truing. It seems others have done the same
NAPA rotors were the worst to be warped coming out of the box. The NAPA rotors had a note in the box stating that all rotors should be machined prior to installation.
Ooh, good to know. Is that due to rough shipping/handling or just a crappy supplier?
No one ever gave an excuse. As I recall the owner of the NAPA store seemed very “matter of fact” in telling me to turn them the first time that I complained.