Ok, as some of you know we bought our '06 HHR a little over a year ago at the end of April. It had just a tad over 150,000 miles on it, now there is just a tad over 170,000. The folks who traded it in did so because they were convinced the front end was about to fall off.

The dealer put new rotors and pads on the vehicle and replaced the shoes in the rear.

Since then one of those silly W springs broke and locked up the wheel last fall and I had to buy all new stuff to fix it. Earlier this spring I noticed that the drivers side front wheel would pulse a bit when you put the brakes on fairly hard.

Knowing that it had just had the rotors and pads replaced I was convinced that something else was causing this pulsing. We made a run to Tennessee so the wife could visit her sister in October and it seemed to be getting worse.

When we got home I replaced the outer tie rod ends. I jacked the car up off the ground and ran my dial indicator on the braking surfaces of the rotors looking to see if the disks were warped or perhaps the wheel bearing was going out.

My tests were conclusive. The wheel bearing was fine the disks were not warped.

Fast forward to now. Here we are in hot and muggy Tennessee again and,... I just beat the old disks off the front end, replaced them with new ones {and new pads even though the old pads show less than 1/16” of wear}, and my problem is gone.

On the interstate I was put into a panic stop situation, I think the dude who cut me off was a little asleep at the wheel, I stood on the brake peddle and it felt like some one was using my drivers side front wheel to do some Harlem Globe Trotter style dribbleing.

Back when we bought the car I asked the mechanic who had done the work on the HHR and he guaranteed me that genuine GM disks and pads had been used.

It has Auto Zone disks and pads now. If I remember I'll report on how they hold up next year.

 

One of the key issues with the new pads is to assure they are beaded in correctly. Have you done this? "hyperV6" wrote a very interesting post regarding this process and provided links to performance brake websites that give very good explanations. You might try to find that.

Also, make sure your rear brakes are doing their part. Even though the car has "self adjusting" rear shoes, many have problems with the self adjusting and have elected to do a manual adjust. NOTE....I believe the self adjusting problem is more prevalent in the colder climates where snow, rain, slush, dirt which has an adverse effect rendering the self adjusting useless.

A reasonable "test" for the self adjusting is to see if the hand brake requires more than about 4-5 clicks. If it does, they probably need adjusting.

And obviously you realize that when they are not working correctly, the fronts are doing all the work, which may cause overheating and front brake material to "layer" causing the shudder effect.

 

I've readI've read all manner of things about bedding disk breaks and I agree that when you use ceramic material brake pads it is a real good idea.

I just used the semi-metallic pads on this job but still more or less bedded them anyway. Its just something I have always done after doing a brake job on drums or disks.

I rarely have drums or roters turned, they have to be very grooved and if they are that bad I usually replace them rather than have them turned.

Anyway its just a thing I do, and have done for around 45 years of fooling with cars. I did check the rear brakes since I was working on the thing anyway had the jack out and all and the rear wheels are adjusted correctly just one click on the adjuster stopped them firmly so I clicked them back that much. Evidently when I did the rears last fall and cleaned the adjusters I did it right.

 

Grizzly-

Does your '06 have ABS ?

 

sounds like you had the common issue with the gm parts of heating up the rotors during highway braking, then coming to a stop. This can cause pad material to fuse to the rotors in one spot, which feels like warped rotors.
Ive found that careful braking for a while afterward can actually reverse that, no need for refinishing or replacing them.
After almost 5 years/90k im still on the factory brakes, about 3mm left on the pads.

 

Sleeper,
No my buggy does not have the ABS brakes.

Prod,
That may be what happened last fall, because it did seem to get better through the winter. You would think I might have seen something when I checked things out with the dial indicator tho.

I had a heck of a time getting the rotors off. I bent a prybar then dinged the breaking surfaces on both sides hitting them with a 4 pound hammer.

I can honestly say I have never had so much problem getting disk brakes off any other car. Most disks you just belt them a good one with yer big hammer and they pop off.

Not these buddy.

When the pry bar bent it slipped and I managed to ram the handle into my ribs. It hurt plenty at the time and still hurts today probably will for a few more days. I can't see any bruising but that's what it feels like.

I took the car out on the the interstate a few miles and ran it up to the posted limit of 70 mph then put the brakes on fairly lightly a few times to get the disks warmed up then put them on more aggressively. The drivers side front tire still bounced a little but not nearly as bad as before, so I'm still wondering whats going on.

Perhaps a bad strut?

 

I'd say your strut is probably packing it in on you, wheel hop like you're describing sounds a bit odd, but when a strut or shock starts to fail it can happen.

One thing to check is the tire itself, if the strut is bad, then the tire will be oscillating enough to pick up a funny wear pattern that will exacerbate the issue. Unfortunately, when a tire starts to "cup" it'll keep wearing that way until its worn out, you may wish to rotate it to the back just as an experiment to see if the wheel hop is lessened when you brake.

With 170k on the clock, your struts are pooped out, once you replace them it'll feel like you're driving a new HHR again.

 

When I had the tires off to get to the disks I did inspect them specifically looking for signs of cupping and did not see any.

If I were at home I have two big hydraulic floor jacks so I can jack up both ends at the same time and can do a tire rotation in little time.

My brother in law here in Tennessee has one rather anemic hydraulic floor jack. I suppose I could dig out the jack that came with the car but as far as I know it has never actually been used on the car.

I still wonder about the wheel bearings. More so since I know for a fact that the disks and pads are for a certainty not the problem at this time.

The way we used check for bad shocks was to jump up and down on the bumper and see how long it took the car to stop rocking. Well, HHR's don't really have a bumper but by opening the drivers side door and standing on the edge of the floor and clinging to the roof rack I got it bouncing pretty good. When I jumped off it almost immediately stopped rocking.

This leads me to think the struts are OK. Also when on bumpy roads it rides decently.

 

The travel of the suspension is to short to do the old timey bounce check for bad shocks.

Have you inspected the control arm bushings?

 

I guess it's time for a, HUH