thumping while braking

[beerdog]

Anyone ever experience a thumping while braking? One of the 98's does this.

-Feels like driving over bumps in the road.
-more intense at higher speeds.
-no steering while vibration.
-hard to tell if it is from the front or rear.
-calipers and rotors are relatively new.
-Fluid flushed regularly so it is not old or dirty.

 

[driller]

My guess would be a worn suspension component shifting when decelerating. Strut rod bushing perhaps?

 

[billcu]

Sounds like brake rotors to me. If you can't feel it in the steering wheel, I'd check the rears first.

If you have a dial indicator, you can check for runout.

 

[beerdog]

most of the suspension parts are relatively new. The vibe did feel more from the back.

 

[paskevich]

Let's narrow the situation down scientifically. Is the bump constant with what you would consider a single tire rotation? Or is it more in sync with what you would consider drive shaft rotation?

 

[ussnewco]

I'm late to the party but thought I would share for future users, I had that that exact problem on my '97 Mark and it was the lower control arm bushing that had not been tightened properly or re-tightened after the car was lowered. I swear I was just trying to get my wife (Ms. Leadfoot) to stop driving my car. I hope this helps.... someone.