I am not sure if this is totally pertinent to your question, but I think it may be. I bought a vehicle and upon braking it would shake/shudder something terrible and the faster the speed at which braking needed to be done the more the shake/shudder. Turned out to be rotors on mine. Had the bearings repacked (these may need replacing also, have the person doing the job check). Because of the shake/shudder and the way it can groove the rotors and or brakes from the rotors, I had new brakes put on in spite of being told that new brakes were put on prior to my buying this vehicle. I went with ceramic brakes (ceramic brakes do not squeak like the others do because they are a softer material, and yes, you usually pay more, but it is worth it I feel). Now it rides smooth as can be when braking. You may want to do a specific search on your vehicle such as the example below: 1999 Chevrolet shakes when braking after an automobile accident? You may get more specific answers and some sites also allow searching within the site under your particular vehicle type. I am not sure, but other things to check before putting out big money on rotors and such is to check for tire balance, front end alignment, treads on tires may be separating from the belt(s), tie rods if yours has them, sticky caliper, upper and lower ball joints, etc. As stated not sure, but can't hurt to ask when getting things checked so you do not pay for what you did not need in the first place. Your best bet is to have a free front end check and let them tell you and then go on-line and research what they state to see if it states the same. I took my car for a front end alignment and was told that I needed $1200.00 worth of work when it was not true. Seeing my brother was my mechanic he would have told me if this was the case and it is not the first time I have had mechanics tell me this kind of thing. I have found that if you go to a small independent shop you will get a better deal and outcome that is more honest more times than not. I have not found Firestone to be honest on more than one occasion this is not to say they are all like this, but it is buyer beware when money is involved. That is another thing when someone does work, ask to see the parts taken off that are being replaced and have them explain to you what is bad or wrong with the part. Good luck, I hope some of this helps you!
not usually. warped rotors will cause a vibration during braking.
warped rotor
No, warped rotors will cause vibration when braking.
replace front brake rotors and pads.
u have bad roters in front
The reason is most likely a problem of warpage in the front rotor disc and/or disc drum in the back. If your tires are out of roundness, it can also be the cause.
Only if you are braking at the time. A more likely cause is a failing CV joint or a worn ball joint.
Could be a vacuum leak
you could have worped disk brakes. or your brake pads are not level with your disk brake
This can be a warped rotor or tire out of balance. If it only happens when braking it is a warped rotor.
Check for warped front rotors. under slight brake application it may not shake. But under hard braking such as getting off an offramp the truck will shake and the brake pedal may pulsate slightly. Chances are real good this is your problem.
You may need a wheel alignment, or you may need bushings.