Warped Rotors
06-29-2010 | 04:11 PM
#1
Thread Starter
Member
Joined: 02-02-2009
Posts: 41
From: Binghamton, NY
Warped Rotors
So today for the 3rd time in the 2 years I've owned my HHR I had the rotors replaced because they got warped. I had them put on better rotors and pads (needed new pads to) and I hope they will last more than a year. But what could have caused the other ones to warp? and in such a short amount of time.
06-29-2010 | 04:56 PM
#2
Senior Member
Joined: 10-14-2006
Posts: 375
From: Rockport, Tx.
I have an 08 with 22,000 on the clock,, never once have i had a rotor issue. Im wondering if it has a lot to do with ppl in heavy traffic areas, stop and go all the time. We dont have much traffic around here.
06-29-2010 | 05:56 PM
#3
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
First off you need to understand the rotors do not warp. Once you understand that it no longer hides the true issues that cause the pulsing brakes.
RTV Rotor THickness Variation is one of the prime causes. THis is where the hub bearing has more than 0.002 of play and the rotor wobbles driving down the road. THis caused the rotor to wear uneven in thickness and cause the pedal to pulse. If the rotor was just warped the caliper is floatng and would float with the rotor if it was at even thickness.
The other issue is Brake Material embedded to the rotor. IF the pads are not seated or bedded in after installed they can create a spot or two that will under hot conditions embest the brake lining material into the rotor. Think of it like if you spilled coke on the kitchen floor and then tried to slide accross it in your socks. THe spot where the coke was will stick and mess up your slide.
Few mechanic seat in or bed the brakes. This is when you make a series of stops in to put a coating of pad material even on the entire rotor. It helps prevent the pad material from sticking in one spot. Kind of like greasing a frying pan to keep the eggs from sticking.
Most shops also do not instruck people on how to drive or seat the brakes upon pick up. Often New cars and cars with no brakes are left to have issues due to the fact the brakes were never bedded. Often it can happen short term or even 18,000 miles later. It all depends on you driving and how the brakes are used.
Note not everyone has this issue as many of use either seat the pads or some do it with their driving not knowing they did.
There is nothing wrong with the rotors and this issue is common on most cars today. The real issues are with the bearing hubs on most new cars. Most MFG have gone to a ball bearing over a roller. It has less rolling resisitance but it also wears faster. They do it for more MPG.
Few people check the hubs and many out out of spec by 70,000 miles. Few people change them till they hear them growl.
Note the pulsing brake issue came into its own around time these hubs came out.
In cutting the rotors what some mistake for warp is really the thickness of the rotor being out and that is why they cut uneven when you start them on the lathe.
Check this site out and there are many other like Bendix.com tech section that explain this well. http://www.stoptech.com/tech_info/wp...rakedisk.shtml
I used to feel the same till I learned the truth and I no longer as do many other have this issue anymore.
FYI there are several proper ways to seat brakes and most work well. Read up and learn to do one and it will save you future issues if done properly. The first 500 miles on the pads are the most important.
Note stopping hard on a off ramp and getting the brakes really hot and then standing on them on rotor that were not bedded in will put the pad material right into the rotor.
RTV Rotor THickness Variation is one of the prime causes. THis is where the hub bearing has more than 0.002 of play and the rotor wobbles driving down the road. THis caused the rotor to wear uneven in thickness and cause the pedal to pulse. If the rotor was just warped the caliper is floatng and would float with the rotor if it was at even thickness.
The other issue is Brake Material embedded to the rotor. IF the pads are not seated or bedded in after installed they can create a spot or two that will under hot conditions embest the brake lining material into the rotor. Think of it like if you spilled coke on the kitchen floor and then tried to slide accross it in your socks. THe spot where the coke was will stick and mess up your slide.
Few mechanic seat in or bed the brakes. This is when you make a series of stops in to put a coating of pad material even on the entire rotor. It helps prevent the pad material from sticking in one spot. Kind of like greasing a frying pan to keep the eggs from sticking.
Most shops also do not instruck people on how to drive or seat the brakes upon pick up. Often New cars and cars with no brakes are left to have issues due to the fact the brakes were never bedded. Often it can happen short term or even 18,000 miles later. It all depends on you driving and how the brakes are used.
Note not everyone has this issue as many of use either seat the pads or some do it with their driving not knowing they did.
There is nothing wrong with the rotors and this issue is common on most cars today. The real issues are with the bearing hubs on most new cars. Most MFG have gone to a ball bearing over a roller. It has less rolling resisitance but it also wears faster. They do it for more MPG.
Few people check the hubs and many out out of spec by 70,000 miles. Few people change them till they hear them growl.
Note the pulsing brake issue came into its own around time these hubs came out.
In cutting the rotors what some mistake for warp is really the thickness of the rotor being out and that is why they cut uneven when you start them on the lathe.
Check this site out and there are many other like Bendix.com tech section that explain this well. http://www.stoptech.com/tech_info/wp...rakedisk.shtml
I used to feel the same till I learned the truth and I no longer as do many other have this issue anymore.
FYI there are several proper ways to seat brakes and most work well. Read up and learn to do one and it will save you future issues if done properly. The first 500 miles on the pads are the most important.
Note stopping hard on a off ramp and getting the brakes really hot and then standing on them on rotor that were not bedded in will put the pad material right into the rotor.
06-29-2010 | 06:40 PM
#4
Senior Member
Joined: 03-06-2010
Posts: 6,869
From: Ohio
I'm not doubting this explanation, but I have to wonder what happened to those vehicles that have had tires rotated or new tires put on and the lug nuts over torqued/improperly torqued, no brake work done and had immediate brake pulsing on the first stop..... brakes were fine going into the shop. That is obviously not the same issue. So what's that all about?
I've read of this happening several places on the net and talked to one guy in person about this. His was an HHR that he no longer owns, but it happened at around 17K miles....... Rotation was done at a local "stealership" and they said rotor warp when he took it back. Of course they wouldn't admit it was anything they did, it was "coincidence" they said (Was an '06 HHR and this was probably sometime in '07 or '08)
I've read of this happening several places on the net and talked to one guy in person about this. His was an HHR that he no longer owns, but it happened at around 17K miles....... Rotation was done at a local "stealership" and they said rotor warp when he took it back. Of course they wouldn't admit it was anything they did, it was "coincidence" they said (Was an '06 HHR and this was probably sometime in '07 or '08)
Last edited by Greybeard999; 06-29-2010 at 06:41 PM. Reason: Spelling
06-29-2010 | 07:05 PM
#5
Moderator
Joined: 01-23-2009
Posts: 25,339
From: Fredericksburg,VA
My current skepticism(sp?) is that my "warped rotor" feel is not a pedal pulsation, but a shuddering, and it is not every time I apply the brakes. New hubs,new struts, new rotors, rotating the wheels (with proper torquing) have all been temporary fixes.
The pedal does not actually pulsate, but the whole car shudders (like when you open only the front window at high speed). But, not every time! It has got me just accepting it, the next time I rotate maybe it will go away for a while again. H'mm maybe it is that the the lugs need to be torqued more frequently than rotation is recommended? It seems that after looking at what I just wrote, that is the common item.
The pedal does not actually pulsate, but the whole car shudders (like when you open only the front window at high speed). But, not every time! It has got me just accepting it, the next time I rotate maybe it will go away for a while again. H'mm maybe it is that the the lugs need to be torqued more frequently than rotation is recommended? It seems that after looking at what I just wrote, that is the common item.
06-29-2010 | 09:23 PM
#6
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
I'm not doubting this explanation, but I have to wonder what happened to those vehicles that have had tires rotated or new tires put on and the lug nuts over torqued/improperly torqued, no brake work done and had immediate brake pulsing on the first stop..... brakes were fine going into the shop. That is obviously not the same issue. So what's that all about?
I've read of this happening several places on the net and talked to one guy in person about this. His was an HHR that he no longer owns, but it happened at around 17K miles....... Rotation was done at a local "stealership" and they said rotor warp when he took it back. Of course they wouldn't admit it was anything they did, it was "coincidence" they said (Was an '06 HHR and this was probably sometime in '07 or '08)
I've read of this happening several places on the net and talked to one guy in person about this. His was an HHR that he no longer owns, but it happened at around 17K miles....... Rotation was done at a local "stealership" and they said rotor warp when he took it back. Of course they wouldn't admit it was anything they did, it was "coincidence" they said (Was an '06 HHR and this was probably sometime in '07 or '08)
What we were addressing here is the most common issue that most complain about. The Lug torque can be an issue but often to a lesser degree.
06-29-2010 | 09:28 PM
#7
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
My current skepticism(sp?) is that my "warped rotor" feel is not a pedal pulsation, but a shuddering, and it is not every time I apply the brakes. New hubs,new struts, new rotors, rotating the wheels (with proper torquing) have all been temporary fixes.
The pedal does not actually pulsate, but the whole car shudders (like when you open only the front window at high speed). But, not every time! It has got me just accepting it, the next time I rotate maybe it will go away for a while again. H'mm maybe it is that the the lugs need to be torqued more frequently than rotation is recommended? It seems that after looking at what I just wrote, that is the common item.
The pedal does not actually pulsate, but the whole car shudders (like when you open only the front window at high speed). But, not every time! It has got me just accepting it, the next time I rotate maybe it will go away for a while again. H'mm maybe it is that the the lugs need to be torqued more frequently than rotation is recommended? It seems that after looking at what I just wrote, that is the common item.
THis is a case where if the pads are seated or bedded the material will most likey not embed and create this condition.
Material sticking or embedding in the rotor can be a long term or short term issue as in many cased it can clean it self up after some later stops. It just depends on the Pad material, and how embeded it is on the rotor.
Wheels need to be torqued once installed and checked again in about 25-30 miles. No need to check them again after that. 100 FT-LBS should be all you need.
Like I said read up and check the web site tech info on Bendix, Raybestos, Stop tech etc. They all offer very good info and how to get good service out of the brakes. There is no conspiracy with the car companies as some like to believe. Just some good solid rules and procedures you need to follow that even some very good mechanics fail to perform today.
Even with a new car off the lot you need to bed in the brakes as the factory did not do it. That coating of lining on the rotor is very important to prevent the sudder and pulse issues.
06-29-2010 | 09:35 PM
#8
Senior Member
Joined: 03-06-2010
Posts: 6,869
From: Ohio
Thanks for the explanation, hyperv6........ once they distort can they at times stay that way? In my mind a distortion is a "warp" if you get my drift....... It just seems that some people may be experiencing brake "issues" and it could be one or the other problem.
06-29-2010 | 10:07 PM
#9
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
Sometimes just releasing the lugs and retorquing can bring the rotors back. Just depends how hard they were cranked down.
I just see people complain with issues I see that could be resolved if they just know what is going on. I learned the truth and just try to pass on what fixed my issues once I was taught by someone else.
06-30-2010 | 06:12 AM
#10
Senior Member
Joined: 07-17-2006
Posts: 6,052
From: Dallas, GA
It can be a play on words. This has been discussed here numerous times. You put a rotor on a lathe and it does not spin true, that "distortion" is a warp.
You may not like the term, but rotors can warp. Granted there can be other factors also. But rotors can warp under excessive heat. That has been proven numerous times.
That's all the time I'm spending on this.
Brake rotors are a critical component of a vehicle's braking system. Designed with smooth, low-friction outer surfaces, brake rotors are designed to promote smooth, easy vehicle stopping, as they are the parts of a vehicle that spin in relation to vehicle speed and are gripped by the vehicle brake pads to affect vehicle braking. Although durable in design and long-lasting, brake rotors can become damaged and/or warped. What follows is a brief list of the most common causes of warped brake rotors.
Defective Brake Pads
Brake pads that are defective and/or incorrectly installed can, over time, cause brake rotors to warp and become damaged. Brake pads are responsible for squeezing against the spinning brake rotor, an action that causes a vehicle to slow down or stop. If the brake pads are bent, misshapen in any way, or aligned and/or installed abnormally, they can exert abnormal pressure on the brake rotors, a condition that can cause brake rotor warpage over time.
Abnormal Brake Caliper Action
An abnormal or malfunctioning brake caliper can result in brake rotor warpage if the degree of brake caliper dysfunction is severe enough. A brake caliper houses a set of vehicle brake pads and provides the squeezing force necessary to squeeze the brake pads against the spinning brake rotor. If a brake caliper applies too much pressure to the brake pads, or if it applies pressure inconsistently, it can cause a brake rotor to warp over time. Adequate brake caliper action is necessary for optimizing brake pad and brake rotor function.
Excessive Heat
A vehicle's braking system generates a tremendous amount of friction-related heat, heat that normally gets radiated away from the brake pads and brake rotor mechanisms. However, in cases where excessive heat is generated within a braking system and not dispersed adequately, serious brake malfunctions can occur, which can include brake rotor warpage. A stuck brake caliper, old, worn-down brake pads, or a defective brake rotor can cause excessive heat to develop in or around a brake rotor, which can cause brake rotor damage and warpage.
Physical Damage
It's very common for brake rotors to become warped as the result of physical damage sustained during the changing of a flat vehicle tire. When a vehicle is raised to allow removal of its vehicle tire, a common mistake that many people make is to not use jack stands to keep the vehicle supported; instead, many people will simply use the vehicle jack to both raise and support the vehicle, a situation that can lead to severe brake rotor damage if the vehicle jack loses hydraulic pressure and allows the supported vehicle to crash to the ground. The exposed brake rotor is the first vehicle part to contact the ground, and it normally suffers severe physical damage, including warpage.
Damanged Wheel Hub Spindle
A brake rotor assembly is supported by and rides on a long, slender metal tube called a hub, or wheel hub assembly. The hub is what allows for the smooth, even circular motion of the spinning brake rotor. Designed with a smooth, low-friction exterior, the wheel hub assembly is critical to the proper spinning motion of the brake rotor. Any abnormalities or defects with the wheel hub assembly, including hub warpage, cracking or misalignment, can cause abnormal brake rotor rotation, which in turn can cause brake rotor warpage over time. Normally, a damaged wheel hub assembly is noticed and remedied prior to extensive brake rotor damage, as a severely damaged wheel hub assembly will cause a vehicle tire to wobble and shake, a condition that normally leads to a quick, thorough vehicle inspection.
Defective Brake Pads
Brake pads that are defective and/or incorrectly installed can, over time, cause brake rotors to warp and become damaged. Brake pads are responsible for squeezing against the spinning brake rotor, an action that causes a vehicle to slow down or stop. If the brake pads are bent, misshapen in any way, or aligned and/or installed abnormally, they can exert abnormal pressure on the brake rotors, a condition that can cause brake rotor warpage over time.
Abnormal Brake Caliper Action
An abnormal or malfunctioning brake caliper can result in brake rotor warpage if the degree of brake caliper dysfunction is severe enough. A brake caliper houses a set of vehicle brake pads and provides the squeezing force necessary to squeeze the brake pads against the spinning brake rotor. If a brake caliper applies too much pressure to the brake pads, or if it applies pressure inconsistently, it can cause a brake rotor to warp over time. Adequate brake caliper action is necessary for optimizing brake pad and brake rotor function.
Excessive Heat
A vehicle's braking system generates a tremendous amount of friction-related heat, heat that normally gets radiated away from the brake pads and brake rotor mechanisms. However, in cases where excessive heat is generated within a braking system and not dispersed adequately, serious brake malfunctions can occur, which can include brake rotor warpage. A stuck brake caliper, old, worn-down brake pads, or a defective brake rotor can cause excessive heat to develop in or around a brake rotor, which can cause brake rotor damage and warpage.
Physical Damage
It's very common for brake rotors to become warped as the result of physical damage sustained during the changing of a flat vehicle tire. When a vehicle is raised to allow removal of its vehicle tire, a common mistake that many people make is to not use jack stands to keep the vehicle supported; instead, many people will simply use the vehicle jack to both raise and support the vehicle, a situation that can lead to severe brake rotor damage if the vehicle jack loses hydraulic pressure and allows the supported vehicle to crash to the ground. The exposed brake rotor is the first vehicle part to contact the ground, and it normally suffers severe physical damage, including warpage.
Damanged Wheel Hub Spindle
A brake rotor assembly is supported by and rides on a long, slender metal tube called a hub, or wheel hub assembly. The hub is what allows for the smooth, even circular motion of the spinning brake rotor. Designed with a smooth, low-friction exterior, the wheel hub assembly is critical to the proper spinning motion of the brake rotor. Any abnormalities or defects with the wheel hub assembly, including hub warpage, cracking or misalignment, can cause abnormal brake rotor rotation, which in turn can cause brake rotor warpage over time. Normally, a damaged wheel hub assembly is noticed and remedied prior to extensive brake rotor damage, as a severely damaged wheel hub assembly will cause a vehicle tire to wobble and shake, a condition that normally leads to a quick, thorough vehicle inspection.