Brake judder/shimmy when braking at low speeds

I have a 2000 Mitsubishi Mirage. I’ve been having issues with judder. I first mentioned it to a mechanic late last spring, but they said the rotors and pads were fine, so I let it be, and the judder got gradually worse, until I brought it in again a couple weeks ago and got new front rotors (the rotors were warped at that point, and barely within spec). But as I left the mechanic’s, I realized that the judder had not gone away, it had just changed, and become more pronounced. (Yes, I should have gone right back in to the mechanic, but I was peeved that the problem was still there, and sleep deprived from working 3rd shift.)

The judder is most noticeable when I am stopping in town. The car behaves as if I’m stomping on the brake repeatedly; the brakes are grabbing and releasing, grabbing and releasing. Until the past week, this has meant that my head bobs front and back a bit as I stop. In the past week though, it feels like there is a tiny bit of side-to-side movement developing, too. The steering wheel does not shake, and I can’t feel anything unusual in the pedal.
(Also, if it matters, the tires were rotated about a week before the rotors were replaced.)

What could the issue be here? Should I take it back to the shop and ask them to undo and redo the lug nuts by hand, since I’ve read that overtightening, or tightening in the wrong order, could be an issue? Should I ask them if they test run-out when they install rotors? Should I go to a different mechanic? The mechanic I went to is a local large operation with a decent reputation, but… I’ve gotten some conflicting information from them, depending on who I talk to. Also, should the pads have been replaced along with the rotors? They’re at around 70%.

Were the pads worn evenly from end to end? If the caliper is binding on one end the caliper will be forced into the rotor unevenly and judder. Lack of lubricant, worn caliper guides, worn guide bushings, etc can cause the problem.

A warped rotor will cause the steering wheel to pulse left to right when stopping and undulate the deceleration.

could be a burst steel band in the tire, very hard to see sometimes…

I don’t know of any professional repair shop that would install used brake pads on new rotors. No matter how much friction material is left on the brake pads

If the friction surfaces aren’t correct between the brake pads and rotors when they’re installed, the brake pads might not embed properly and the proper transfer of friction material might not occur.

If this were my vehicle I’d start all over. New brake pads and rotors.


“… the brakes are grabbing and releasing, grabbing and releasing.”

If they are grabbing and releasing in time with wheel rotation, I’d look to the rear brakes.

I agree with tester but at this point, I would try the hard stop trick. Find a safe place to do this, hit the brakes hard from about 60 mph, do not let them lock up but just short of that. When you get down to about 5 mph, accelerate and repeat. If it doesn’t correct itself after two hard stops, then it isn’t going to.

I would then replace the pads and make sure the caliper pins are free. A light sanding of the new rotors should be all they need. The follow the instructions to bed the new pads. Since the Mirage was an entry level car, it probably has drum brakes on the rear and they are not the problem.

I’d have to agree with @insightful. You may have a warped brake drum in the rear. It happens.

a bad tire can feel that way too

@wesw Yes it can.

I had a ford that could rust the brakes causing that symptom in less than a week. Given enough driving and braking does the shudder go away?