Pulsating car
 

I can feel the car slightly pulsating forward and backward as I brake descending a hill. The steeper the hill the more noticeable it is. I can also see my passenger's head bobbing a little with the car. Lol. Hmm maybe I shouldn't laugh. Once I'm stopped at the bottom of the hill the motion is gone. Brake pedal not pulsing. On a level road coming to a quick stop I don't notice anything. Also can feel a bit of vibration in the steering wheel and front end when on the highway at 65 mph.
Still occurs after doing the following:
Tires rotated front to back and vice versa.
Driver's side tie rod replaced and car aligned.
I had a mechanic rotate the tires because when I tried to remove one, the lug bolt was not turning when applying force with the lug wrench and pipe extension. I didn't want to apply too much force because I thought I might break the bolt. The tires were probably over-torqued but that would be about a year ago and the problem is just now appearing. There's plenty of material on the discs and brake pads. The outer circumference of the disc is rough, but does not appear to be a contact area. Shocks seem to be ok when pushing on the front left or right fender. Not bouncy at all.
Does this appear to be brake related or suspension related?

warped rotors?

Thanks, it was the rotors. I brought the car to a local mechanic and told him to check the front end and also the rotors. He said he has seen the over-torquing causing problems. He said he was unable to properly measure the rotors so he had them turned and put in new pads. Problem disappeared, but it wasn't until yesterday when I traveled to the two steep hills where the problem previously was extremely noticeable that I could verify that the problem was really gone. Problem is gone.

Here's a link explaining that the rotor doesn't actually warp but gets brake pad material deposited on it.

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml#

And here's a discussion on this Mercedes site where I got the link.

http://209.85.215.104/search?sourceid=navclient-ff&ie=UTF-8&q=cache%3Ahttp%3A%2F%2Fwww.peachparts.com%2Fshopforum%2Fshowthread.php%3Fp%3D1199652

actually your not supposed to turn mercedes rotors. They recomend replacement. I bought some not long ago, I want to say maybe $50/side? If you are going to go through the trouble of removing them, you mine as well replace them and repack your bearings.

He should be able to measure them, I think the minimum thickness is ~12.9 It is stamped on the rotor itself, get a red shop towel and wipe the brake dust off and look very carefully. On the genuine benz rotors, it says on the top wide ridge, on the ate's its stamped on the thinner ridge.

He was referring to measuring them for warpage when he said he couldn't measure them.

I never heard that a rotor cannot warp. Interesting, since I have turned rotors on an Ammco lathe, and during the set up, you can see where metal is cut in the high spots and not touched on the low spots. That is a warped rotor, not left over brake pat material.