Rotors and vibration

subaru
forester

#1

Hello!

Last August I had 4 new tires put on my Subaru and the following month, in September, I had my front brake pads replaced and the rotors “turned.” I rarely drive on the highway, but in March I took a 5 hour trip and noticed that each time I braked while going above 60 mph, my whole car started to shimmy and shake…So, when I had my tires rotated at the end of April, I mentioned it to the guy at the repair shop. He said it was probably a rotor…So, I said, “Well, they were turned when you guys replaced the brake pads last September, should I be having a problem with them now?” So, the owner of the shop said, “No, you shouldn’t be.” He had a mechanic look at them and the owner said they would have to “fix it,” but they couldn’t do it that day - I’d have to come back next week. So, I did. And that time the mechanic said it wasn’t the FRONT end that was the problem - my rear brake pads needed to be replaced - they were down to 3 mm or whatever…So, they replaced the rear brake pads and said that was the cause of the vibration.

I took a trip over the July 4th holiday - and my car still shakes like a blender when braking at high speeds!

My question is - is it reasonable to expect them to “fix” the rotors, assuming they turned them last September? Is this just something that can happen? I try to maintain my car so it doesn’t happen…but I don’t want to go back to them and demand they “fix” it if it isn’t something they shouldn’t be responsible for. I guess I have that idea because of the owner’s initial response that they would have to “fix it.”

Any advice would be appreciated.

Thank you.
Laura


#2

Yes, sometimes this just “happens” especially when rotors are turned instead of replaced.

This can also happen with brand new rotors as well, if not properly manufactured. By your description there is a rotor that needs to be replaced. And if one needs it, the opposite side should be done, too, to maintain even braking. And you should get it fixed soon.

Should the shop pay for it? I think not. They might give you a discount on the labor of replacing the rotors as a goodwill gesture but you should still pay for new rotors.


#3

Mustangman is right. You have a “warped” rotor. This can be a defect in the turning process (unlikely) or can be caused by heat. The heating and cooling of the rotor causes it to become slightly misshapen. My guess is that the front rotors were turned and the reduction in material resulted in less material to absorb the heat from braking. That caused the rotors to warp and thus, you now feel the shake. You mention a “Shop” did this work. I have nothing against “shops”. and I use a great one, but most dealers, and more and more shops, won’t bother to turn (machine) rotors anymore. It is a waste of shop time. Most use new rotors ready to be mounted and the time savings match the cost adder of the new part. The biggest plus is that the risk of warping is much lower since the rotors have the material mass as originally fitted. The past few times I had brakes done on my Lexus and Toyota vehicles both the Lexus dealer and my local shop used new rotors instead of turning the ones on the car. Based on what you describe, the warped rotors are on the front, not the back. I also agree that you probably needed rear brakes anyway. The situation you now face is the shop won’t want to re-do the front brakes for “free.” This is all labor and materials. I’d find a more modern shop.


#4

Thanks. It is a reputable local repair shop…I guess what I don’t understand is why the owner said they’d have to “fix it,” and then when I went back - they said it was the rear brakes…I don’t think I trust their opinions anymore…Which is a shame because I’ve bought my tires there for years! I usually do more complicated things at the Subaru dealer.


#5

This is when you find another repair place. Look at Yelp or some other online review site. Maybe you know someone who had brake work done and could recommend a place.


#6

Yes, I don’t think there was any intent to take advantage of you based on the info given. I think the shop actually may have tried to do the work as cost effectively as possible. My guess as to why the second trip didn’t result in a diagnosis of a warped front rotor? Pride.


#7

Unless the owner, at the time of your visit, inspected the brakes he may have only guessed based on your description. With what I read, I give him the benefit of the doubt. He could have told you anything to get out of a free repair, but offered to do so if it was due to the shops initial work.


#8

I’m going to suggest a different approach from some of the other comments.

When the shop turned the front rotors and replaced the pads, they were responsible for checking whether the remaining thickness was still within specifications. If the rotors weren’t thick enough, they could warp as described by others. This is another reason why replacing rotors makes sense in many cases.
(And for a couple of questions, how many miles did you drive between Sept and Mar? And how many miles ago did you last have brake work done? The second question gives info on whether you ride the brakes excessively.)

If you only drove relatively few miles locally without excessive braking riding, sufficient thickness should have remained after turning, and warping should not have occurred.

So my view is that they were paid for possibly iffy work on the front rotors, and work on the rear brakes. I suggest you go back with a deal in mind.
First check another shop for an estimate of replacing the front rotors. Then have that price in mind and return to the first shop and get an estimate from them for the same work.

Then suggest that they check your front rotors for warping AT NO COST. If they are warped, suggest that they have the chance to do the work of replacing them but that you would only pay half of the labor along with cost of the rotors. IOW, the first shop should split the labor cost with you (and restore your confidence in them, and so that you don’t discourage others from them)… .
Of course this only makes sense if you still trust the first shop to some degree and the final price would be better than the other estimate you get.


#9

About 10,000 miles since I had the brakes done last September. I’m within the 12,000 mile warranty on the brakes - that is what the owner said - because when he said they needed to fix it, I asked about the cost and he said I was still within warranty. I have my receipt and they didn’t replace the rotors - they just turned them - so I’m not sure how a warranty would apply, but that is what he said. I really don’t think I ride the brake. I’ve had the car since 2013 and the brake pads last September were the first I’ve had to put on the car.


#10

I don’t see where you bought the car new or what year it is or how many miles it has on it. Frankly I don’t see any choice but to see if the place will make a deal on new rotors for the front and if not go somewhere else.


#11

I agree with Waterbuff that you should try to work out a deal. Sooner rather than later. Any issue with the brakes isn’t something that you want to put off. If they aren’t able to resolve the issue than it’s time to find a new shop.


#12

I’ve already called them…I’m going back over there Thursday.


#13

I bought the car used from the Subaru dealership in 2013. It had about 50,000 miles on it when I bought it and 100,000 miles on it now. I’m going back to see them on Thursday.


#14

See if you can find your records from the rear brake work to get a better idea of how many of those 10,000 miles were between Sept and Mar. That’s the mileage during which warping might have happened.

Putting your comments together, it sounds like you went about 40,000 miles before the shop did your front brakes. Even if the front brakes were new when you bought the car, it doesn’t sound like you brake excessively (unless those 40,000 miles were all highway).

You will probably want to have this info ready in case it’s needed when you go back to the shop. Good luck!


#15

I don’t see where you mentioned the model year of your subie, but presumably this isn’t a new vehicle. Brake work is expected as the car ages and w/more miles. I don’t see there’s any reason to be worried your shop isn’t doing a good job. On the other hand I don’t expect they’ll fix whatever’s causing the brake shudder problem gratis either. The car ages, more miles, new problems always crop up and have to be dealt with as they happen is all. Myself, I’d have probably consulted with the shop tech at the time they were advising to resurface the rotors, asking for a “replace” vs “resurface” cost estimate. Sometimes the shop will have the resurfacing equipment there and decide they want to use it, when the better approach is actually to just replace the rotors. But that cost/benefit ratio depends on the various parts and labor costs, which depends on how the car is designed. I don’t own a subies so can’t comment on that. But next time you go to the shop, see if you can steer them to install new front rotors. They could also measure the thickness of the existing ones, compare that to the specs, and measure the run out and compare that to the specs too.

One other thing that can cause warped rotors, the wheel nuts are not torqued properly during the installation of the wheel. That could have happened when you purchased new tires for example. Ask your shop if they’ll check the torque on the lug nuts after you buy tires again. Whenever a shop installs wheels on my car, diy’er me, the first thing I always do is take it back to the driveway, loosen all the lug nuts and re-tighten them properly. To avoid this kind of problem in the first place. But your shop might be willing to do that for you if you ask.


#16

Good point. Although the brake work was after the new tires were put on. So any over tightening would have been after the brake work.