A strange, intermittent, and mildly annoying problem. Say I want to slow my car's speed a bit. I lightly press on the brake pedal, and the car shakes a little. It seems like the front end is shaking, I can really feel the "shake" through the steering wheel, and my passenger can feel the car shake too. If I brake HARD there is no shaking. It doesn't shake everytime when I brake. I would say "warped discs" except the problem comes and goes. Also, I would expect the shaking to get worse when I braked harder if the discs were warped. In fact, I am almost certain that this is a case of warped discs, but I can't explain the intermittent shaking.

The shaking isn't very bad, would a very slight amount of disc warping expalin this problem?

Might be riding the disc's and i suggest u go back to ur dealer, and they should replace the disc. The dealer should be the one to repair it, it under warrenty right?

warped rotors is probably the most likely. It doesn't take much to cause a little pulsation. Does the pulsation come and go based on the cars speed and or the pressure you're putting on the brake? You said when you brake HARD is goes away- this may be because the warpage is so slight. Incidently, are your front wheels torqued on properly? I'd go back to the dealer and have the brakes checked out. On such a new car you really shouldn't have to tolerate any sort of thing like that.

warped rotors is probably the most likely. It doesn't take much to cause a little pulsation. Does the pulsation come and go based on the cars speed and or the pressure you're putting on the brake? You said when you brake HARD is goes away- this may be because the warpage is so slight. Incidently, are your front wheels torqued on properly? I'd go back to the dealer and have the brakes checked out. On such a new car you really shouldn't have to tolerate any sort of thing like that.

 

Might also be the wheels are out off balance, there for then u brake it could cause that effect.

I wonder if he has a sticky caliper. I'd have to ride in the car myself to see if it was transmission related jerking or wheel related jerking. Since it's so new, just take the car back and make the stealership fix it.

It should be pretty easy to tell if it's the front end or the tranny, and since the car is so new it's highly unlikely to be tranny related. Also that it only occurs when braking. It would also be very unusual, this early, for the calipers to be sticking. If the car is pulling to one side when this pulsating occurs then calipers should be looked at, otherwise they're fine. Again i doubt that is happening. Brake rotors need to be very true to operate smoothly, and from time to time even new rotors may come a tad warped when new. The dealer should be able to clear it up no problem. Years ago, just a few after we bought what is now my car, the front brakes were pulsating and it was taken into the dealer. They claimed that while the brakes were pulsating a little- due to slight warpage- it was "within parameters" and they did nothing about it. Just be careful that the dealer doesn't push the problem aside.

 

Also, the wheels being out of balance might be a possibility, if the pulsating was also occurring while coasting, without the brakes applied. If it only happens when the brakes are applied, it's most likely brake related.

I suggest you guys go to the Stoptech website and read the brake white papers. Those guys are excellent and it may help. you.

On every car I have purchased, new or used, over the last ten years, the first thing I check is the lug nut torque. This usually happens in the first 50 miles. I have not found a single one with the proper torque on the front wheel lugs. This includes Toyotas, Nissans, Fords, Chevrolets, and Subarus. One, or more was always over tightened and sometimes badly over tightened. I have never found one loose yet.

 

This proves nothing but I suspect a lot of warped discs are caused by the use of air torque wrenches at the factory or at the dealers. Sometime, the dealer provides a pre-delivery check sheet and lug nuts are one of the items checked off. Coincidently I have never experienced any warped rotors yet.