Hey I'm new here and recently am having some trouble with my '07 mustang V6. Basically theres never been any problems with the car, and a couple days ago I got 4 new wheels put on, with a new back rear tire (popped it on a curb on black ice). On the way back from the Discount Tire place I noticed that whenever I would go to break, the actual break pedal would pulsate as would the car. I was wondering if anyone had any suggestions as to what this could be, I'm thinking possibly something with the balance or the lug nuts, but then again I'm not exactly the most knowledgable with cars. Any advice is appreciated!

 

When you say new wheels are they OEM or aftermarket? If aftermarket it could be the wheels are wrong offset, need hubcentric rings, or you may have to remove the washers that hold the rotors snug to the hub during assembly. Does it shake when driving or just braking? Did they use toque sticks on the impact guns when tightening your wheels?..if no they may have warped your brake rotors.

 

I agree, take it back & have them put it up on a lift & spin all the wheels, If it's a brake rotor washer then it'll be noticeable, but, if it's ONLY when applying brakes then I'd say they warped your rotors. I'm pretty sure the book calls for 100lbs. Of torque on all lug nuts. Tightened in a crisscross cross pattern. It sounds silly to some people but it really does make a difference on cars these days.

 

They're aftermarket wheels, and it only pulsates when I put the brakes on. I'm almost positive they used impact guns when tightening the wheels since I saw them do it to several other cars while waiting in line (couldn't actually watch repair on my car, had to go to class).

On a side note, I noticed when i break i can hear a squeak sound coming from the back of my car which goes along with the brake pulsations.

 

It is possible with aftermarket wheels that if you leave the little clip on the lug nut (it is used for assembly and can be removed with no issues) that the new wheel won't seat properly. If there are any clips take those off.

 

Would it be the same side you blew the tire out on? Did you hit a curb? You may have a bent axle.

 

That's what I was thinking too after re-reading the original post. I was thinking that before the new wheels you never felt the shimmy but missed that you had to replace it after hitting the curb. So I would look at either a bent axle with the brake squeak, or a warp in the rotor at the least on that wheel.

 

I can tell its coming from the back left, and yeah I wound up in a 180 and hit the curb with the back left too. Also now theres a clicking type of sound coming from the same place while I'm actually driving. So break pulsations, some squeaking, and now a clicking sound when driving

 

Sounds like you have a bent axle.

 

Update: took it into a shop to get it checked on, it is the axle. The question I have now is, how much should a rear axle cost? I've been doing some research on it, but the place I took it into said a new one would be roughly $4000-$5000. Is this a solid estimate?