Snoopy

O'k hyper....it's your turn AGAIN......

Greybeard999

Then you and I have the same problem..... whatever it ends up being. Most people are saying it gets worse as you apply more pressure.



@snoopy...... I've been thinking the same thing. Where is hyper?

hyperv6

Trapper forget the warp factor as if you just clean up or replace the rotors it will happen again. Also the factory rotors are not bad as many think. Too many of us don't have issues for only some to be bad.

Rotor Thickness Variation is a prime factor here. It is often cause by factors like a hub bearing out if spec. Hub bearings should not have more than .002 of play as anything more will cause it to wobble onm the highway and wear the rotor in varing thickness around the rotor. This causes a pulse. The caliper is free floating and under pressure the puse would go away as the caliper and pads would float with it under pressure. It is common for this to happen after intitial application. Most pulse is felt under light application on RTV.

Also if the pads were not seated in or burnished in properly they can leave material on the rotor after a hard hot stop like an off ramp. The hot material on a unbedded rotor can let the pad material stick and cause a place the rotor grabs upon stopping making it pulse. Sometimes it will wear away other time it will take a clean up of the rotor to fix it. Bedding or burnishing in of the brakes and a good quality pad will cure this.

Check this web site out under burnishing in pads and under pedal pulse what it is and why it happens. These will solve about 90% of the issues that many mistake for a so called warped rotor. Misdiagnosed brake issues are often why it always come back again and again.

http://www.bendixbrakes.com/techCorner/faq.php

Note too GM has a technical service bulletin on the Rotor Thickness Variation issues too.

Don't wast time on vented or drilled rotors unless you like the look as they are cosmetic. The slotteds do clear debrie from the rotor surface but do little for cooling. Solid rotors act as the best heat sink possible.

Also as pointed out check the rear adjustment on the drums. Most cars do not have this issues but I have seen some here have an adjustment issue. It may be frozen up or if you don't back up enough can make them get out of adjustment. I have rear disc so on my HHR so I have not seen this issue. I also seated the pads in when I got the car and have never had a brake issues either. I used to on my past cars till I learned to seat them in and I have since never had this pulse issue since.

hyperv6

Where is that Damn Sticky I should post!

Old Lar

I wonder if the sensation is from the anti lock feature of HHRs with that feature. My "06 HHR does not have anti lock brakes and I'm still running the original brakes after 83K miles still with ~50% life left. My last car had anti lock brakes and I always felt pulsations with heavy braking. Those brakes lasted maybe 40K miles.

843de

Maybe its the onset of the ABS activating, but the threshold is set fairly high to keep the system from triggering until you exceed a certain brake force or rate of deceleration coupled with impending lockup of one or more wheels. If you are pounding the brakes hard enough on the highway to trigger the ABS on a regular basis you need to look at modifying your driving style.

I think what we have here is the usual HHR brake rotor issue of thickness variations/warpage/excessive run out, which can all be corrected by the installation of heavy duty rotors and pads. Plus adjusting the rear brakes as a they are most likely sadly in need of it, they shouldn't be called "self adjusters".

ChevyMgr

Silverfox

Anybody tried Ceramic Pads. I've used Raybestos on my other vehicles with good results so far. Nil Dust on wheels too.

solman98

That's the only type I will run.

Silverfox

843,

I think what we have here is the usual HHR brake rotor issue of thickness variations/warpage/excessive run out, which can all be corrected by the installation of heavy duty rotors and pads.


What Brand/Type etc. Rotors and Pads are you refering to ??

SF