Vibration and shuddering when braking at highway speed


#1

Guys, This one is making me nuts. Have a 2000 Kia Spectra. I have had a shudder when braking from highway speeds since I bought it (used). Thought it was pads and rotors so had pad replaced and rotors turned. No change. Thought maybe new rotors would help. No dice. The shudder is not felt in the pedal as is normal with warped rotors. Vehicle shuddered on the way home from repairs so pretty sure the rotors are fine. It doesn’t happen at lower speeds; say 25 mph. Has to be going more than about 35 mph. I also have to brake hard. Gradual/slow application of brakes is smooth. What next? Can’t shoot it. It isn’t worth the bullet.


#2

Had the exact same symptoms on my 95 Taurus & it was loose inner tie rod ends.

Try jacking it up & grab the tire at 3 and 6 o clock. Is there much slop when wiggled?


#3

Make that 3 & 9 o clock


#4

Thanks for the suggestion. Just checked. Tie Rods solid throughout range of motion.


#5

First, with the car on the ground, have someone move the steering wheel back and forth quickly and watch all the steering and suspension components. If something is loose, it should become obvious.

I’m not big on this warped rotor thing everyone else around here is so quick to jump on, but, I just bough a new set of rotors for my Saturn made by a company called EBC. They’re British, but the rotors were made in the US. They aren’t cheap, but I read the instructions that came with them while taking a rest. They recommend doing a runout test when installing the rotors, not because the rotors are warped, but because the hub may have a build up of rust or other debris that is keeping the rotor from mating flat to the hub, or the hub may be warped. If you don’t find any loose components, you might have this checked out.


#6

Also, check for a SLIGHTLY bent spindle or wheel hub. Put a dial indicator on the edge of the rim and rotate it.


#7

Front brake problems are usually noticeable in the steering wheel on rack and pinion cars; not the brake pedal.

If the pedal has a faint pulsation or you can feel it in the seats, then this would point to a rear drum problem.
Run the car up to speed and apply the park brake(not foot brake) to stop it. If you feel the shudder then it’s a drum problem.

Had any tires put on at any time by someone with a heavy duty air wrench in their hand? Overtightening wheel lugs will distort brake drums, and in some cases will even distort the face of the wheel itself if the vehicle has steel wheels.


#8

Would worn struts do this? Car has close to 120k.


#9

Tried your suggestion about the hand brake. Worked. Thanks. Now that I know where its coming from it should be easy to fix.