Pulsing/Shuddering when braking at high speeds

I felt a pulsing/shuddering in my car when I was braking, especially at high speeds. I took the car to the mechanic said he my rotors were warped, so they replaced the rotors and pads, after which the brakes felt fine. It’s now 6 months later and I’m having the same problem. I took it to the mechanic again, and he said the brakes and rotors look fine (nor rust or warping), and they can’t find anything wrong with the car. Any thoughts on what else could be causing the shudder? The car is old: 1995 with 250,000 miles on it.

Rotors are probably a little warped again. Causes: cheap rotors, over-tightening wheel nuts, your braking style?

There are several things that can be going on, all of which are on the shop that did the brakes. What kind of shop was it? A big auto “care” type of chain?

Did they actually test drive the car and feel the pulsing? If so, what is their explanation?

Sometimes this kind of problem can be related to worn front end parts such as bad tie rods. When is the last time it had an alignment or had the front end generally inspected?

Then there is a long list of things that messes up brake function is this way:

  • sticking calipers or caliper slides overheating the pads & rotors
  • unevenly torqued lug nuts (noted)
  • failure to completely clean the hub to rotor mounting surface.
  • cheap brake pads that can leave residue on the rotors, creating an uneven braking surface that gets worse over time
  • your own braking style (noted)

and I’m sure a few other things will come to me.

Thanks for the comments! A few additional points:

-The mechanic I went to is not part of a chain. It’s a place I’ve been taking my car for years, and they’ve been very trustworthy in the past.

-They did test drive the car and felt some pulsing, but I’m not sure they took it on the highway to test the braking at high speeds. They didn’t have a good explanation for what I felt.

-They took apart the brakes and cleaned everything out, and I’m picking up the car this evening. I’m going to have a friend test drive the car to see if they can feel the pulsing when braking.

-As I said, the mechanic has been reliable in the past. If we assume it’s not the brakes, what else could it be? The car is old - any chance that issues with the suspension, etc could be causing this problem? I haven’t had the front end checked lately or an alignment done, so I’ll check into that.

Thanks for your help, and I’ll let you know how it turns out!

Any looseness at all in a wheel bearing, suspension component, etc. can mimic a brake shudder.

I hope this mechanic is not eyeballing rotors and pronouncing them fine. There is no way of doing that.
This is what micrometers, rotor calipers, etc. are for; to measure and to remove any guesswork about whether the rotors are defective or not.

At that mileage it’s quite possible something else is loose and it doesn’t have to be very loose either; a few thousandths of an inch can do it.