Overtighten Lug nut (causes rotor warpage)?

[rauljimenez]

This is something that has bothered me a bit. My girlfriend sent his car to an auto mechanic to change her brake pads and put new wheel studs. As soon as she got out of the dealer she started to notice her brakes were pulsating.

Do you guys think the reason her brakes are now pulsating is become some ******* used an air gun to tighten the lug nuts and possibly overtightened it, causing rotor warpage??
She never had that problem before she brought the car in, thanks

 

[obbop]

"This is something that has bothered me a bit. My girlfriend sent his car..."

Bothers me, too. Gender bending???

Ahem....

Back to the topic......

Sounds possible to me. I have read in too many manuals about taking care to not over tighten and to tighten in the proper manner.

Get the critter back and demand satisfaction. A dial indicator can be used to check for warpage.

Of course, maybe the pads just need to be seated. There is debate as to how to properly seat new pads. Some folks mumble that a few high-speed quick stops are needed (while avoiding overheating) while some whisper that normal braking should be done.

If after some use setermine of the pulses still exist. Don't wait too long. Get out on the road and drive stop drive stop drive stop. See if that helpd. Perhaps have a third party who is fairly knowledgable of automotive systems see how the brakes feel.

If you have doubts, get it back and demand satisfaction. Of course, the greedsters will likely proclaim a part needs replaced to fix the problem unrelated to the work they did. That gives them a chance to undo what they did wrong while getting some more money out of you.

 

[rauljimenez]

Lol definitely my fault on the gender bending but you made me laugh a lot. I'm gonna definitely take it back since she had never experienced the pulsation before. They used this air gun and im afraid they overtightened it way more off spec than it is supposed to be thus warping the rotor. Any more opinions welcomed

 

[Drew99GT]

Definetally a possibility. Did they turn (machine) the rotors too? It's usually standard procedure for a brake job. Perhaps they did a crappy job on that.

 

[moribundman]

quote:

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"This is something that has bothered me a bit. My girlfriend sent his car..."

Bothers me, too. Gender bending???

---

Not necessarily. She could have taken her husband's car to the shop.

 

[frankiee]

I don't think the rotor would warp.
My concern is if they tightened enough or properly cleaned the areas of assembly after putting in new wheel studs.
Rotor warpage can occur after a hard stop because of the uneven cooling rate between the air cooled area of the rotor and the part that is between the brake pads.
Regardless, take the vehicle back ASAP and have them find the problem.

 

[nel]

Depends on the car. On BMW's, overtightening the lug nuts (in this case, lug bolts) will cause rotor warpage. To keep weight down, the rotors are thin enough at the hat area that overtightening will cause distortion. Happened to me once when the Costco tire tech was in a hurry and torqued down the wheels beyond 200 ft-lbs. with an impact wrench.

 

[mechtech]

The pads may need more time to seat, and burn off mfg. deposits.
Overtightened lugs, especially unevenly, will eventually warp a rotor. It takes heat and many heat/cooling cycles, though.
The hubs, rotors, and wheels, have to be very clean, and free of corrosion on the mating surfaces.