Chrysler Pacifica shudders when braking after new rotors and pads

My 2004 Pacifica (130k miles) was left parked for 2 weeks while we were away. Upon return it didn’t wqnt to back out of the parking spot. After about 1/2 revolution the wheels made a clanking sound and hung up. Rolling back and forth freed things up enough to drive the car to the mechanic (about 40 miles). And after the first mile or so everything seemed to go back to normal, with no absolutely signs of anything not wanting to turn smoothly… The mechanic thought that the problem had been that the brakes were sticking due to the car being unused and said nothing needed to be done. However, upon examination he found that we could use new front brakes and 2 motor mounts. He said that the need for brakes and motor mounts was due to normal wear and tear, and was not related to the wheels hanging up issue.

But now, immediately after installation of 2 new front rotors and pads and 2 new motor mounts there is a vibration/shudder when braking from anything more than 20-30 mph, which was never there before. The shudder is rapid and sometimes pronounced like going over the warning groves cut into the edges of pavement on the interstate. He thinks that this may be a sign that there is a driveshaft issue, and dismisses it as due to an out of round rotor since they are new. I don’t know what to think. By the way, he has always been an excellent mechanic, with a great reputation and loyal following.

Could be loose or unevenly torqued lug nuts. Check runout (side-to-side wavering) of each rotor. New rotors can have quality issues. If the problems arose after his work, I think he owes you more than his vague hypothesis.

If the rotors were installed on rusty hub flanges, this can cause rotor run-out which will cause the brake pedal to shudder when braking.

Here’s what I use to remove rust from hub flanges to prevent this.


I agree with Tester. I’m a DYIer, not a pro, and I always wire brush the rust off the mounting surfaces. Some rotors come coated in something that should be removed before installation. Any unevenness at either surface can bring on runout, and pulsation.

How about the rear brakes? They may have started to shudder just now. If the rotors and the pads both look like crap, here we go again! It’s a typical BOAT problem; Break Out Another Thousand.