Intermittent resistance when turning wheels by hand

[iamtheari]

Over the winter, I had my brake rotors machined and installed new brake pads. I also adjusted the parking brake and I definitely had it too tight. Before I even put the car back on its feet, I turned all four hubs by hand and noticed intermittent resistance. I took the rotors and calipers back off and put them back on very carefully, and still had the same thing. After driving the car, the same thing occurs.

It's like there is resistance through one third of the rotation of the wheel. I feel it at all four corners and the scraping sound of a brake pad on a rotor seems to be at the corner I am turning on all four, but it's possible that the differentials are causing me to feel opposite-side resistance on the close wheel.

Thoughts? What did I do wrong? Should I order new rotors and eat the cost of having the old ones machined? They had only been machined this one time since new. Rotors aren't cheap, but brake failure or instability under braking result in needing a lot more than rotors. I just don't want to spend the money unless I know that is likely to be the problem.

[iamtheari]

The more I think about this, the more I suspect that the mating surfaces between the rotors and the hubs were simply not clean enough. I took it all back apart tonight and sprayed the rotors and hubs with brake parts cleaner until I ran out. I think I will give it some time with steel wool. I don't have an angle grinder to put a wire wheel on but I wonder if it would be overkill to borrow one.

Anything else I should do to ensure the rotors mount up flat against the hubs?

And in the rear, there was intermittent resistance even with the calipers off the car. That means the parking brake shoes are also rubbing. But that could easily be due to the crooked rotors.

Good thing I only drove a little bit. My shiny new pads should be salvageable.

[wwest]

Nothing is perfect, very slight run-out of rotors will cause this effect.

[iamtheari]

After pulling the rotors, brushing the hubs clean, and putting the rotors carefully back on the car, that was my conclusion: very slight run-out. Thanks for confirming.