Date: Fri, 25 Jul 2003 12:19:39 GMT From: 'nuther Bob <yetanotherphonyaddressnopsamacereally.com> Subject: Re: Vibration when braking?
On Fri, 25 Jul 2003 09:42:10 +0100, Grunff <grunffnopsam.com> wrote: >I'd be interested to know exactly how you've reached your >conclusion about modern rotors being "designed to wear out in >combination with the pads" - especially any documentation to >that effect. I think the difference (why rotors wear out these days) is actually due to the pads. Pads used to be made of asbestos and managed to act as a bit of a heat sink on the rotors. Now the pads are semi-metallic in some kind of a base so that they don't pull out as much heat _and_ the metallic particles cause more wear on the rotors. >AFAIK, modern rotors are made of the same steel rotors used to >be made of 20 years ago. Pads have got slightly harder, but >certainly not to the point of necessitating rotor replacement at >60k-80k. Well, more folks seem to be warping them, that's for sure. Rumor has it that initial rotor thickness is less so that the rotors wear out earlier but I've never seen any spec's to compare. But, some folks will need to replace them, some won't. You don't really know until you put them on a lathe and measure. >What's more, worn rotors won't cause vibration when braking; >rotors which have warped will. Brand new rotors can warp just as >easily as rotors which are worn to their minimum thickness. Yeah... I've heard theories that rotors warp primarily to uneven torque from allowing tire monkeys to work on your car. Always check the bolts with a torque wrench after anyone removes or installs wheels, then again after 200 miles or so. I don't know if it's true (the torque/warp theory) but it can't hurt. To the OP: You most likely do have warped rotors. You need the brakes done. You'll need pads and rotors turned or replaced, most likely. Not necessarily front and year, maybe just one or the other. How many miles on your car/brakes ? Bob
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