SSRBOB

The brakes on my stock C-6 are pulsating. Just replaced the front rotors and pads but the pulsating continues. Could the rear rotors
possibly be warped and cause this ? This is the third time I've
replaced the front rotors. They seem to last about a year and then the
pulsating returns. Any ideas ?

Thanks

RicK T

Without being able to inspect them I have to say it is unlikely that your rotors are warping....and rotors definitely don't wear out and need replacing like you've done.

If you haven't already done so, take a good look at the rotors to see if there are blue or black spots/areas on them. Most likely you have an uneven buildup of pad material on the rotors which causes the pulsing. If that's the case, and maybe even if it isn't apparent, try doing a proper bedding of the pads. Tell us what kind of pads you have and we can probably tell you the procedure, or at least a good general procedure that should work.

Check this discussion for more info:

https://www.corvetteforum.com/forums...ck-rotors.html

djbrun

Check your run out on your rotors with a dial indicator.

Did you make sure the interface between the hub and the rotor was clean and flat?

DJ

kevinkar

I've read many explanations that rotors don't warp but they do get bedded in improperly leaving imperfections on the rotor surface from the pad material that feel like pulsing and thus "warping". I think the fix is to swap out the pads for a set of semi-metallic pads and bedding them in properly to remove any of the previous pad. Or resurfacing the rotors.

Stoptech has a good write up of it here: http://stoptech.com/technical-suppor...nd-other-myths

AORoads

All the above is good advice. I will say that when I replaced pads (not rotors) on my '08 "just because" years ago, the bedding in process was very, very limited. Maybe it was the pads, and maybe it was the tech doing the work, but it really didn't need more and that's been true for the past 40K miles since installation. That isn't necessarily the way it is with other pads.

I think you need to do one of the techniques above, at least in a limited way, to bed in the pads with the rotors. And sometimes with other cars, I have found if your brakes begin to squeak, you need to hit it hard (in a safe manner, under safe conditions---no one following you within a car length) to rub off some deposits.

Boomer111

Sounds like a high spot on the rotator or pad. Does it just pulsate when applied? Sometimes the corner of the pad and rotor rub.

In another recent thread a member had an similar issue and it turned out to be a sticky caliper pin.

SSRBOB

How do you "Bed in the pads" ? Presently, I'm planning on replacing the rear rotors and pads this weekend. We shall see if this solves the problem.

AORoads

Take a look at the post by kevinkar and the stoptech brake url. It's long-ish, and somewhat complicated to do since you have to find a good, quiet, long stretch of road(s), but it does do the job.

zali0104

The two main thing that can cause brake pedal pulsation. The most frequent cause is " rotor thickness variation. " This occurs about 100 miles after rotor becomes warped and the high spots wear down and the pads move in and out as it passes over rotor surface. Rotor warping usually occurs after driving through water with hot brakes. Also rotor quality has a lot to do with it. The cheap crap from china is poor quality iron and from my 22 years experience as a mechanic can testify to that. I recommend the the dealer stuff or aftermarket steel.
You may also want to inspect your wheel bearings. Worn bearings cause the rotot to move laterally between the brake pads resulting in brake pedal pulsation.
Hope this helps.

Chevy-SS

I have a 4-post lift in my garage, and I use a magnetic mounted dial indicator to check runout on each rotor every time I do a brake job on any car. It's easy to get a piece of rust or crud between the hub and rotor, which will cause excessive runout.

Here's a pic of the basic method, which is very simple. I try for .001" to 002" maximum runout.... NOTE: in this pic (Ford F150), the rotor is attached to the hub, but if it was loose, then I would secure it with lug nuts.


Additionally, you need to clean the rotors thoroughly (with brake cleaner prior to installation. Often times there is rust preventative of some sort on the rotor, which must be cleaned off. And be EXTRA careful not to get greasy hands on t he clean rotor!

My last suggestion would be the actual tightening of the lug nuts. Snug them all lightly, then tighten in two or three steps, using criss-cross pattern to specified torque (using torque wrench). I see guys all the time who hammer the first lug nut home with impact driver, and then they slam the other lug nuts down, unaware that they may have caused a distortion in the rotor by the uneven clamping force.

-

SSRBOB

Replaced rear rotors and pads over the weekend. Problem fixed. No more pulsing.
Thanks everyone for all the suggestions.
Bob

Delbert

Might check for worn/loose tie led ends. Been known the contribute to wheel shake when braking. Always check for warped rotors first!

Boomer111

Even new rotors and pads can have mating issues.

Skanlez

Hey everyone, I know that this might be an old thread but had a question. I recently started getting pulsing while braking and read that the rotors may need to get turned. I called my local chevy service center and the Corvette expert says that rotors on a C6 Z06 cannot be turned and if bad will need replacing. Is this true?

I called them to find out how much it would cost to have them turned and that's what they told me. I recently had a mechanic check my brakes when I slapped on new tires and they said it was fine. So I'm sort of lost. Thanks.

NY09C6

They can be turned. The issue is finding someone to do it, many won't.

Be sure it's not pad deposits causing the sensation before you cut/replace them.

Skanlez

Thank you for the quick response. I'll call around.

Skanlez

Yup, called another shop that I usually go to and said they'd do it for around $150.

Purple92

I truly hope that the $150 isn't the price to turn 2 rotors !!!

It used to run about $10/rotor to have them cut (that's you bringing the rotor to the machine shop) - now it's typically $20 - $25/rotor.

Skanlez

It actually is for 2 rotors. I called another shop down the street from my place and they quoted me somewhere around $200.

Skanlez

Just spoke to another shop that said he chages $20 a rotor but said if they are drilled or slotted (which the Z06 is drilled) that they cant be resurfaced.

is this true?