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Possible warped rotors info needed.
Hello All, I have a C5 that I’ve installed the C6 Z06 brake caliper and rotors (installed in late 2006) and now the left front wheel is making a “pulsating rubbing noise” with NO brake pressure applied. Noise does go away with the light brakes applied. I have removed the rotor and caliper and the wheel bearing hub has no noise when spun and has proper play when using a dial indicator as per Timken’s instructions.
I suspect the rotor my be warped….Does anyone out there have the C6 Z06 brake rotor run-out specification? (below is the C5 procedure with C5 Rotors).
Thanks in advance!
Kevin

1. Clean the rotor surface.
2. Fasten a dial indicator to the steering knuckle so that the indicator button contacts the rotor surface about 13 mm (0.5 in) from the outer edge.
3. Set the dial indicator to zero.
4. Turn the wheel one complete revolution and observe the runout indicated on the dial. The Total Indicated Runout must not exceed 0.008 mm (0.003 in). In some cases excessive lateral runout of the rotor can be improved by indexing the rotor on the hub one or two bolt positions from the original position. If the lateral runout cannot be corrected by indexing the rotor, check the hub and bearing assembly for excessive lateral runout or looseness. If the hub and bearing assembly lateral runout exceeds 0.040 mm (0.0015 in) then replace the hub and bearing assembly. If lateral runout is within specifications then refinish or replace the rotor as necessary.
Notice
Whenever the brake rotor has been separated from the wheel bearing flange, clean any rust or foreign material from the mating surface of the rotor and flange with the J 42450 hub cleaning kit. Failure to do this may result in increased lateral runout of the rotor and brake pulsation.
5. If lateral runout exceeds the amount specified in step 4, refinish or replace the rotor.

elh0102

It's unusual for a rotor to warp. I would be more suspect of pad deposit buildup, and would re-bed the pads as a first step, if you have not already done it. I've never measured runout in a rotor, since I have never considered having them resurfaced and just replace them. But, mine always crack from heat stress way before wearing to the minimum thickness. If you drive yours only on the street, maybe resurfacing makes sense.

BEZ06

Take a look at this StopTech article on "warped" rotors:

http://www.stoptech.com/tech_info/wp...rakedisk.shtml

Bob

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Undy

Before you condemn the rotor ensure the area between the rotor and spindle face is clean and free from debris, nicks or burrs. Then reinstall the rotor,retorque the wheel to specs and recheck runout.