About 8 months ago my 02 cavalier brake rotors were replaced because they were warped. Again I’m getting the same shaking feeling in the steering/front end while braking. It seems to happen almost at any speed. Could my brakes be warped again? And only after 20 000 km?
Unless you overheated youre braking system. If not I would look into getting youre rear brakes adjusted. Or inspect the rear brakes for replacement if nesscery.
This is a quote from the Suspension and Brake FAQ's
#5 Why do rotors "warp"
They don't. The vibration you feel in the pedal that everyone explains to you is a "warped" rotor is actually a thickness variation in the rotor. If a rotor was warped, it would simply wobble slightly side to side and the caliper (which SHOULD slide freely) will follow it back and forth and no problem will ever be noticed. Most brake vibration problems are caused by rust or dirt build up or a slight runout in the hub. The outside diameter of the hub is maybe 2 or 2.5 inches from the centerline whereas the outside diameter of the rotor is between 5 and 7 inches from the centerline, depending on the car, and possibly more or less, depending on the brake system. This means that .001" or .002" of runout at the hub will translate into .006" or more of runout at the OD of the rotor. This indicates a slight rotor friction surface "wobble". As the rotor wobbles, it will touch the pads slightly at one point on the inboard surface and at another point on the outboard surface. The pads will eventually wear the rotor slightly at these two points causing a thickness variation in the rotor. Instead of floating the caliper back and forth, a thickness variation will force the piston back into the caliper and then let it back out slightly, multiple times throughout one revolution of the rotor. As the piston moves into and out of its bore in the caliper, it moves the fluid into and out of the master cylinder, which is mechanically connected to the brake pedal. This is why a vibration is felt in the pedal. There is also another reason for the cause of brake vibrations...but for this one, I will have to give credit to the rocket scientist STEVE RUIZ of STOPTECH, our sister company for his exemplery explanation..check out this page
http://www.stoptech.com/whitepapers/warped_rotors_myth.htm
Alont
My wheel lug nuts were overtightened when my tires were rotated. Shortly thereafter my brakes started to vibrate/shake when I applied brakes.
To cut a long story short, it turned out my HUBS had become warped because of the uneven and over tightening of the lug nuts. It took removal of the studs from the hub and having the hub faces machined on a milling machine in order to even up the mounting face of the hubs. Luckily I knew a person who did it for me.
So have your hubs checked for run-out before you put on new rotors and start the cycle all over again. Also, never ever bang the studs out of the hub with a hammer. They must be pressed out. I did it with a big engineering vise using sockets from my tool set at the back of the studs. The socket must be just big enough to let the stud go through. The studs must also be pressed in when the mounting surface of the hub is fixed.
Sounds like warpage to me. Avoid driving through deep water or puddles. When hot rotors are inundated with cold water, they can warp instantly.
warpy warpy warpy
get them machined or get new ones
they probably warped when you braked really hard or you tighten your lugs past their threshhold
Lees04Cav wrote:Sounds like warpage to me. Avoid driving through deep water or puddles. When hot rotors are inundated with cold water, they can warp instantly.
Ah no.
Going by that almost every car on the road would have warped rotors.
If anything hitting them with cold water is good because it cools them down.
- 2004 Cavalier - 124k, owned since new
The hubs are relatively much softer than the rotors and are easily distorted by over tightening. Especially uneven over tightening. People tend to overlook this fact. There is a company that makes special tapered shims of different thicknesses to fit between the hub and the wheel to compensate for run-out of the hub.
So as I've said, before you fit new rotors, first check the run-out of your hubs or you'll be back to square one again with pulsating brakes.
yeah if hot rotors are immersed with cold water they will warp, a little splash here and there wont hurt them but if they are very hot and cooled down instantanisly there gonna warp dude ,face it...people do it all the time at car washes ,they get off the highway do some city driving in 90" degree heat and sizzle ther brakes with coold water at a spray and wash..i work at a parts store and dealerships hate that ...(on new cars under warrenty) and yes there is a proper way to brake in new pads and rotors......certified bish
Freak04 wrote:yeah if hot rotors are immersed with cold water they will warp, a little splash here and there wont hurt them but if they are very hot and cooled down instantanisly there gonna warp dude ,face it...people do it all the time at car washes ,they get off the highway do some city driving in 90" degree heat and sizzle ther brakes with coold water at a spray and wash..i work at a parts store and dealerships hate that ...(on new cars under warrenty) and yes there is a proper way to brake in new pads and rotors......certified bish
I never said there wasnt a proper way to break in new pads and rotors. I'am a technican at a Nissan dealership ( eight factory certifactions by the way). I do it on a daily basis.
As far as warpage being caused by cooling them down with water, if you choose to believe that because someone else said I dont really care. I went to school for a long time for auto repair and know facts, and the fact is, it wont warp them.
- 2004 Cavalier - 124k, owned since new
By far the most common reason for rotor warpage is over tightening the lug nuts. Especially if they are torqued up with an impact wrench. It gets worse if they are not tightened in a star pattern as in the case of a 5 lug wheel and, if each nut is tightened to different value.
Get a decent torque wrench and torque your own to spec. which in the case of the Cavalier is, 100 lb - ft (140 N - m). Use a star pattern and tighten each nut a bit at a time until tight. These figures are for DRY nuts. Do not ever put grease or lubricant on the nuts or studs. If you do lubricate them you will end up by exceeding the torque specifications by a very large amount.
Rob S wrote:I'am a technican at a Nissan dealership ( eight factory certifactions by the way). I do it on a daily basis.
As far as warpage being caused by cooling them down with water, if you choose to believe that because someone else said I dont really care. I went to school for a long time for auto repair and know facts, and the fact is, it wont warp them.
This is why I do my own repairs. The dealership is the last place I would ever take my cars for service. In my experience, people who insist that they know the facts, seldom actually do. Experience and knowledge teach one thing more than anything else, and that is Humility (i.e., just how little each of us really does know). I am not an expert by any means, but my statement about cold water possibly warping overheated rotors is something I have heard and read for over 30 years. Maybe it's no longer valid due to improved materials or something, but it was considered common knowledge in my day. I was just trying to be of some help to the original poster. In either case, it still wouldn't hurt to avoid deep puddles when you have been riding your brakes.
Edited 1 time(s). Last edited Sunday, November 19, 2006 8:37 AM
Lees04Cav wrote:Rob S wrote:I'am a technican at a Nissan dealership ( eight factory certifactions by the way). I do it on a daily basis.
As far as warpage being caused by cooling them down with water, if you choose to believe that because someone else said I dont really care. I went to school for a long time for auto repair and know facts, and the fact is, it wont warp them.
This is why I do my own repairs. The dealership is the last place I would ever take my cars for service. In my experience, people who insist that they know the facts, seldom actually do. Experience and knowledge teach one thing more than anything else, and that is Humility (i.e., just how little each of us really does know). I am not an expert by any means, but my statement about cold water possibly warping overheated rotors is something I have heard and read for over 30 years. Maybe it's no longer valid due to improved materials or something, but it was considered common knowledge in my day. I was just trying to be of some help to the original poster. In either case, it still wouldn't hurt to avoid deep puddles when you have been riding your brakes.
Well, usually hot ass metal + cold water = bad things. So... I see exactly why you say that.
1983 Camaro Z28
