2006-11-12 04:49:25 · 7 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
It could be that the brake pad has worn out and is fluttering. If you have antilock brakes it could also mean that one of the calipers is funky.
Very likely it is the rotor. Nowadays the brake rotors that are being installed on vehicles have terrible raw materials, and have hard nodules inside of them so that as the rotor wears these nodules stick out, creating grooves in the brake pads. Once the manager of the the shop I take my car to showed me the scrap bin for all the parts he was throwing away that day. There were over a dozen rotors, most from recently purchased or serviced cars, and all the rotors had chunks missing, or bubbles/pock marks from poor casting, or hard nodules embedded in the matrix. I was not in for brakes, so I know he would not be trying to con me. And if that was just from one day, you can tell he's been seeing more than he tells.
Best thing, take it to a Midas or a Meineke or such and have them change the oil and rotate the tires. Chances are you will be needing to do that soon anyway. Ask them to take a look at the brakes when they take the tires off. They will call you back and let you know what is going on.
2006-11-12 05:05:47 · answer #1 · answered by anon 5 · 0⤊ 0⤋
I'm glad the rest of these guys listed off what it possibly could be, and all the theorys of why it could be that. I work at a parts store, and i'm a third gen. mechanic. It's time for a brake job. You more than likely will NOT have to change the calipers or any of that. The pulsing happens because your pads/shoes are grabbing too hard at the particular point in time your car jerks forward. This "pulsing" should start as soon as you press the brake, and slow down fairly evenly till you actually stop Meaning your rotors/drums are not "square" anymore. Replace the shoes/pads, and have the rotors and/or drums turned. If you happen to be in the more eastern states, O'reilly Auto will turn these for about 10 bucks a piece. Either way, you may or may not need NEW drums/rotors or any of the rest of that. Just new pads/shoes, and have your drums/rotors resurfaced or replaced depending on how thin/trashed they are. Your mechanic, or the people at the tire shop, auto store, etc. will be able to tell you if the drums/rotors are turnable. The min. thickness (rotors), or the max dia. (drums) should be stamped inside around the bolt holes (rotors), or somewhere around the outside edge (drums). These are min/max safe working measurements AFTER being resurfaced. Most resurface jobs remove, in general, 5-10 thousandths of an inch (.005-.010") (.012mm-.025mm). Could be upwards of 30 thousandths (.030")(.076mm). These specs should be checked with a micrometer. Eyeballin with a tape is not good enough.
2006-11-12 06:23:07 · answer #2 · answered by Daniel K 1 · 0⤊ 0⤋
Possibly the front rotors may be warped (excessive run-out measured in thousandths of an inch). There are two other possibilities I can think of too. The rotors may vary in thickness from one point on the disc to another. This will cause the pistons to be forced into the caliper as the thicker part travels around, and for them to be pushed back out again as the thinner rolls between the pads. The result is a pulsation felt both in your seat and the brake pedal. The other problem may be in there rear brakes, either drum or disc. Drums can also be out of round. The way we used to check for rear problems was to simply - and carefully - apply the parking brake (usually in the rear axle) while the vehicle was moving. If there is a shudder, your problem is there. K.
2006-11-12 05:27:01 · answer #3 · answered by kfhaggerty 5 · 0⤊ 0⤋
You mean while it's moving or while it's standing still?
If it feels like it is snatching and releasing, in a pulsing fashion, as you slow then it's probably time for disks (rotors) and pads. I never get rotors turned, there's not much margin on thickness and the cost of new ones isn't all that much, plus nothing is more important than being able to stop.
If it's actually the brake pedal that is jerking while you are standing still then you have more serious problems.
2006-11-12 05:03:05 · answer #4 · answered by Chris H 6 · 0⤊ 0⤋
Without a long winded answer, if you apply the brakes and the steering wheel vibrates, the front rotors are warped, or if the car shakes but steering wheel doesnt vibrate, the rear drums could be out of round, or rotors warped. Simple as that my friend, its time for a complete brake job.
2006-11-12 06:34:46 · answer #5 · answered by bobby 6 · 0⤊ 0⤋
if it feels like a pulsation and your stering wheel shakes your rotors are warped
2006-11-12 05:01:53 · answer #6 · answered by mammawinks03 1 · 0⤊ 0⤋
Either that or there's a squirrel stuck in there.
2006-11-12 04:51:35 · answer #7 · answered by Mr Smarty Pants 3 · 0⤊ 0⤋