Yes i did a search but found nothing. I bought used rotors off ebay (slotted drilled) and they look pretty new. Don't know if they were w****d or not. I replaced the pads with endless. I did brake the pads in properly by going from to 60mph to 5mph then back up to 60mph again. My steeing wheel shakes under hard braking. Is there any way to resurface slotted drilled rotors to see if i can fix the shaking problem? or what do you guys think the problem is? I got them cryo treated also. Any help would be appreciated. Thanks
sounds like they are warped. I thought i read somewhere that drilled rotors usually warp easier for some reason
they are warped.... they are cheap ebay ones... the cross drilled parts are probably wrong and badly engineered... ummm where do we stop?? yes you can turn them.. sometimes out of the box even the good 'American made' ones need a slight resurface.... but if you have put an aggressive pad onto an inferior quality metal rotor then say hello to headaches my friend....
Less material to disapate heat:dunno: You don't ever want holes in your rotors. Just get stock or a set of slotted ones.
I would doubt that you have warped your rotors already. I had a Grand Cherokee that would warp rotors on a regular basis, and I replaced the stock rotors with some slotted Frozen Rotors From Burnsville (and pads that they suggested to go with them). These new rotors made the truck have sort of a vibrating, it was quite different than the warped rotor. The slotted rotors actualy had a vibration of higher frequency and lower amplitude, where the warped rotors had a lower frequency and a higher amplitude. I notced the slotted rotors as a vibration (whole car) where the warped rotors were more like a oscilation (car felt jerky and wheel might shake). what does your shake feel like does the wheel vibrate or turn back and forth from side to side?
again.. rotors can have unevenness out of the box!!!! if it is shaking while braking most likely a 'warped' rotor... or a badly out of balance wheel.. but you would feel that while driving and it rarely happens that way... cross Drilled rotors are fine if you buy ones that are designed for high performance applications by well known manufacturers... why else would high performance race cars run them??? the slots and drilled rotors are designed to remove the brake deposits from the surface area and cool it more efficiently then the gasses being trapped between the rotor and pad surfaces... there is a reason they make them... problem you get is it is kinda like the rice crowd.. one person does something then everyone under the sun copies.. and usually the copy is inferior and poorly designed... hence ebay specials... Buy well known brands.. pay extra up front instead of paying 5 times the same amount by replacing and solving isssues... and about the statement above ^^^ regarding warping rotors already... you can warp a rotor within 20miles... hey I can do a brake job and 2 mins down the road the rotor can get a warp... its called heat and cheap metal... again I state we have machined rotors out of the box from the manufacturer cause they have had warped surfaces from factory.. either they were stored incorrectly (not flat) or poor materials... unfortunately seeing as asia has bought up most the metals that are decent anything you can buy under $80 - $100 per rotor you are probably buying korean made crap full of mixed metals that dont do as well as good quality - dare I say in the same sentence - AMERICAN MADE rotors made with quality materials...
Most standard grade rotors are made in China, Venezuela, or Mexico. The premium rotors are most often made in Canada, Japan, or the U.S. Anyways, wrxboy is right. You can get brand new rotors that are warped out of the box. Its rare, but it does happen. In the case of the OP, he bought used rotors and that's always bad. When a new set of rotors are installed on a car, the car wears the rotors to its own characteristics. Brake calipers are like fingerprints. No two are seated exactly the same. Also, minor discrepancies in how the rotor sits on the hub assembly also make for unique wear-ins as well as how th epads sit in the calipers. So, when you put a new, unwarped rotor on your car, it will start to wear in a way that is even with respect to your car, your calipers, your pads, and your hub assembly. You can put 10k mi on that rotor and have no problems. Then take that rotor and put it on a different car and suddenly, its warped. In truth, it just hasn't worn properly with respect to that car and yes as a result, feels warped. The old rotor on the new car will take a long time to even out and is unsafe in the mean time. Brake parts are the last thing that should be swapped from one vehicle to the next (pads/shoes and rotors/drums especially). The guy that sold you the rotors likely had no problems with them on his car because of what I said above.
Modern pads don't have the gas issues they did decades ago and cross drilled rotors arguably don't do anything for cooling besides hurt it. Good read: http://www.iwsti.com/forums/showthread.php?t=67007
save your rotors by easing off the brakes when you come to a stop. At times you can just come OFF the brakes if your car will not roll when you're stopped. When at a stop light where it goes down hill after coming off the hiway, stop like 5-8 ft from the line, and every sec or so slightly roll forward so you're not holding the pads on the same spot on the rotor. I've gone 116k miles on my STOCK rotors and only on my 2nd set of pads. These have been through a 2day high-speed track event, autocrosses...hard driving......etc... they still haven't shook. But ya, they can be bad to start with.....but then I'm just giving some tips to save yoru rotors....
That you have 116k mi on stock rotors doesn't shock me. My wife's 96 Cherokee Sport had 135k mi on it when I replaced the OE rotors. Unless a driver is exceptionally hard on brakes, OE rotors tend to last over 100k and can be turned at least once. Or at least that's how it used to be. I'm starting to question the quality of brake components used by auto manufacturers these days.
Firstly, it's probably a bad idea to buy used rotors. That's already been gone over. Secondly, cross drilled rotors are less than ideal and can cause problems when the brakes are getting REALLY heat-cycled. You're going to be pushing it pretty hard in that case, but the rotors will probably never see the kinds of temperatures that cause the big problems if all you're doing is normal street driving. I wouldn't run drilled rotors, but they aren't that bad. Just more trouble than they're worth for most people. And third, rotors don't "warp," they get an uneven buildup of brake material. There is a small boundary layer of brake material on the rotor, when the brake pads get heat-cycled and you let your foot rest on a steaming hot rotor, you're liable to leave a "foot print" on that spot in the shape of a brake pad. You get enough of that build up in one spot and all of a sudden you get a "hump" on the rotor that is comonly percieved as warping. I never heard of this until reading these articles http://www.stoptech.com/tech_info/tech_white_papers.shtml The "right" answer for your question is that, in the long run, you'd be better off getting some cryo-treated slotted rotors. I'd be annoyed at best in your situation though, so I'd maybe look at having your rotors turned. This will remove the uneven buildup and, granted you properly bed the pads in, you should be ok. That's the route I'd go if I was going to be tight on $$ or stuburn about just spending money on rotors.
What's wrong with using the handbrake when the car is stationary ? The handbrakes on our cars don't use the caliper, they use something more akin to a drum brake inside the rear rotor. Sitting at a stop light at the top of an off ramp with your foot planted on the brake pedal is a sure fire way to leave brake pad deposits on your rotors. When I bought my car a couple of years ago, it had some shake from the brakes. I was worried about the rotors being warped, but figured is was more likely to be pad deposits. After about 6months of driving, and not sitting on the brakes when the car was stopped, it'd cleaned the muck off the rotors and the shimmy went away. Stuart.
Lets not get all alarmist with this thing here. I have driven a few hundred thousand miles at this point in my life using vehicles such as motorcycles (sport bikes no less), sports cars, compacts, mid-sized, small SUV's, and large SUV's. At no point in my driving experience have I not come to stop lights, top of hills, bottom of hills etc. and not keep my foot on the brake with exceptions for manuals where I disengage the transmission and take my foot off the brake if on an even surface. That I can tell, I have never greatly impacted my rotors, warped my rotors, or prematurely worn out a set of pads. I have used cheap pads, cheap rotors, expensive pads, and expensive rotors in several different combinations. I do make a habit of pumping my brakes when I descend steep hills. I do this as to reduce the chances of warping rotors under heavy extended braking. The bottom line is that if you do not have a reason to suspect that your rotors may be retaining a lot of heat due to heavy use, then drive as you normally would and don't be paranoid about instantaneously warping our rotors. It generally takes a lot to warp a rotor and they most often warp as a result of an improperly functioning calpier, not from leaving your foot on the brakes at a stop light. Whatever minute amount of brake residue that may be left on your rotor from being at a stop light will usually be wiped clean the next time you use your brakes. And yes, there are always situations that exist outside the norm and they shouldn't be dismissed. But, they should not be given the same weight as what usually occurs.
