If cared for, is there any reason you should have to replace the front rotors of a car? My sisters 2006 which she got about 2 years ago are coming up on needing to replace the front rotors for the 3rd time. The first time the dealership replaced them after about 6 months. Those lasted about a year and the dealership refused to do it for free, so she took it to another shop we know and they put on new ones since the ones she had couldn’t be saved she was told (by both places) Well again she is having issues with the rotors becoming so bad the wheel shakes when she brakes. Went to a 3rd place who said she needed to replace these rotors (they had no idea how old they were). She has new pads on the brakes in the front but continues to battle this rotor issue. Is this something with the Chevy HHR or what? The car only has about 55,000 miles on it, she is not a hard braker at all.
One of the things that can warp brake rotors is failure to use a torque wrench when tightening lug nuts on the wheels. Is it possible that your sister, her husband/boyfriend/SO, or her mechanic has used an impact wrench or something other than a torque wrench (calibrated to the correct torque) when changing/rotating tires?
If she is a left foot braker, she could be resting her left foot on the pedal, she could have a bad naster cylinder,or sticking calipers.
Nope, don’t think that is it as she only has had the tires off when having this work done.
Nope on the left foot, this is the first car she has had that this issue has happened and she has owned/driven a number of other types of cars. I have searched the web but haven’t come across this issue with HHR, but this isn’t the only issue she is having with the type of car as I also have posted an issue with her gear box/tranny also here…
“she only has had the tires off when having this work done.”
…and, if the tires were put back on without the use of a torque wrench at the correct torque, the mechanic(s) could well be setting up the situation for the next rotor replacement.
There are cheapo rotors and good rotors, along with what was mentioned above. Sticking calipers can also warp rotors
The fact that she is not hard on the brakes could be why she has so much trouble. when she gets the vibration in the brakes, tell her to find a safe place that the can do some hard (not to lock up, but just shy) braking from about 60 mph. She should not quite come to a stop, at around 5 mph, she should accelerate back to 60 and do it again. Two of these should smooth out the brakes for awhile.
This cleans up the rotors and removes any residues that cause uneven braking.
@VCDriver, technically you’re right about those torque wrenches.
I work on fleet vehicles, so I see the same vehicles every 6 months for service.
My colleagues and I use torque wrenches for head gaskets, manifolds, pan gaskets, etc.
But not for rims.
If we were truly causing the rotors to warp, we’d all be replacing/machining rotors left and right, every day, because we’re responsible for hundreds of vehicles.
I’m not saying it couldn’t happen, but it’s probably not super common.
db4690, Is it possible that you are torquing lug nuts by hand with a lug wrench and the person doing this has a good sense of repeatability in his/her touch? What is your detailed method for tightening lug nuts? Is the OP’s sister’s mechanic using an impact wrench or sloppy with a lug wrench? More detailed input is needed here.
I am of the view that using a torque wrench to consistently tighten lug nuts while increasing the torque in stages to the final specified value helps a lot to reduce pulsating braking but may not be a complete cure.
Are the rotors actually being checked for warpage and parallelism or are the these shops just automatically assuming because the rotors are the cause of a steering wheel shake during braking?
There are a number of things that could cause a problem like this not related to warped rotors at all.
As to warped rotors due to overtightened wheel lugs, I’m not a big subscriber of that idea. Brake drums can be prone to something like this but generally speaking rotors or rotor/hubs are not affected that much. Just my 2 cents.
My feeling is that many problems are more than likely due to hub surface faults, wheel bearing looseness, and so on.
the number one cause of warping rotors is heat, perhaps she gets surprized or caught in traffic more than before.
i would find a shop that can machine the rotors while on the car. as long as they are useable. they will tend to go further before the next service is necessary. also ask her to begin slowing down earlier by coasting and don’t wait till the last minute .
"the number one cause of warping rotors is heat,"
Nothing personal DanielLee, but I see this comment from a lot of people and I really have to question where it comes from. Has anyone ever documented this? I have gotten my rotors so hot that they turned blue and they did not warp.
Anyway, whether this is true or just a myth, its $50 ea plus labor to replace the rotors or $13 ea plus labor to turn them. But it only takes a little gas to find a lonely country road and do a couple of hard stops. If it doesn’t work, then go get the rotors serviced. But most of the time it does work.
For many years and with 3 cars ('81, '85 and '88 Accords) I had chronic problems with OEM rotors warping.
Put on new rotors, after a couple thousand miles they warp, then go get them turned lightly on the car, then maybe 30k miles or so and they warp again.
Maybe 50% of the time they’re thick enough to turn again, and the process repeats.
My mechanic friend at a Honda dealer said this was a common problem and a source of steady work at the shop.
I finally, finally bought some high quality aftermarket rotors for the '88 and they were trouble free for 70k miles until I sold the car.
I still generally stick with OEM parts, but now I’ll make an exception.
circuitsmith, I will agree that the metallurgy and casting process can have an affect on whether a rotor will be prone to warping or not, but I am convinced that not all rotors that give a pulsing feeling are warped.
I experience kind of the same thing on out 97 Honda Accords rotors. I got 170k miles on them, but periodically I had to do a couple of hard stops to minimize the shuddering, especially when the pads were new or newly replaced. I have Wagners on it now and so far, after 13k miles, not a shudder yet. I use Wagners on my daughters Toyota and they have never shuddered either, but she is hard on brakes.
@WhaWho, I’m not using a lug wrench.
I’m using a 1/2" air impact wrench.
Perhaps my trigger finger has a good sense of touch.
LOL
I can’t speak for anyone else besides me and my colleagues in my shop, but we aren’t causing warped rotors.
I have no idea what’s going on in that other shop.
Of course, the right thing to do would be to use a torque wrench every time, but in the real world that’s not always practical or even possible, due to pressure and time constraints.
db4690, no matter what your time constraints are, you should never use an air impact wrench for tightening lug nuts, or anything else for that matter. Impact wrenches are for loosening, not tightening.
Although most people think air impact wrenches tend to over torque, the fact is they often under torque, especially when the operator is in a hurry. Air ratchets are faster and much more repeatable for torque than an impact wrench.
In the real world air wrenches are used constantly for tightening and it’s not a problem in the right hands.
No mechanic should use an air ratchet for the initial loosening or final tighening of any fastener; lugs or otherwise.
Doing so usually means the ratchet head is going to have a short life.
In my real world, which was a manufacturing facility, we had constant problems with loose connections when using air impact wrenches. We switched to air ratchets and that solved the problem, and they didn’t wear out either. They were used on a two shift assembly line all day long and would last about 6 months, which under those conditions was pretty good. In fact the air impact wrenches wore out faster.
We even tried the air torque wrenches used on the assembly line at Nissan. They would last about a year at Nissan (according to the salesman of those very expensive tools), about a week with us.
@Keith, not to criticize . . .
I’ve never had a rim fall off a vehicle
The worst thing I’ve ever done was strip threads on a stud. And that only takes a few minutes to correct.
I don’t know what kind of air ratchets you’re thinking of, but the ones I’m familiar with aren’t strong enough to mount rims.
I have a very powerful 3/8" air ratchet, literally the most powerful one available, and it can’t do it.
Unless I misread your last post, you’re in manufacturing.
Well, I’m in the shop, fixing vehicles, day in and day out. There’s some overlap, but it’s not exactly the same field.
I don’t know everything, but I do know that air impact wrenches are used to mount rims, not air ratchets.
Whether you use a torque wrench is up to you, but impact wrenches are the name of the game.