Warped Rotors?
 

I think I may have a warped brake rotor. Sometimes when running for long stretches on the interstates, i'll brake at high speeds and feel a pulsating sensation. This really only happens on hot days and driving for long distances, my thinking is that the rotors or one rotor is getting toot hot. I've never had a warped rotor before, but does this sound like a symptom? Thanks

Yes,you have wraped rotors.resurface them or replace if arent enough thicker.

Or thickness variation.... fix would be the same, resurface or replace. Pads could be upgraded at the same time (should be, is more like it) Also, when was the last time you had the rear brakes adjusted? They tend to not self adjust and need manual intervention. When they go out of adjustment the fronts do all the work and these pulsing problems are the result. :skull:

Thats an interesting observation Greybeard. That really could be part of all the complaints about warped rotors as you say.

I have found in some cases that what you are saying has happened in years gone by in doing brake jobs back then.
Many self adjusters had not properly functioned and a manual adjustment was the temp. fix.
The only difference then was that drums were used front and rear.

It probably wouldn't hurt to back up and apply some fairly heavy pressure to the brake peddle now and then to help keep the HHR brakes adjusted.

Other wise manually adjust every so often.

Good Point ......

I think we are finding out that the "back up, apply brakes, back up, apply brakes" deal for some reason isn't working on these cars. Even though it's an old design and should work, it seems for many of us it's just not, so I always recommend manual adjustment.

Basically the self adjusters on the HHR should be called "manually assisted self adjusters", always adjust them whenever the rear wheels are off for a rotation and you'll avoid some problems down the road.

I've noticed that I occasionally get pulsing on the initial brake application but not on the second. I have a habit of applying, releasing and re-applying the brakes. I've also noticed that rust forms quickly on the rotors.

Sounds much like what mine do on occasion, Don. Does yours also go away with more pedal pressure?

Yes increased pedal pressure does stop it.

Everybody is Concentrating on the Front Rotors.

Just remember that you could have out of round drums on the rear at the same time.

Some careless tire shop employees do not take enough care in properly Torque Wrenching all 4 wheels.
With heavily promoted tire rotation going on, and re-installing and removing winter tires, your disturbing the status quo on a regular basis.

Just more things to think about on this subject....