Anyone reported brake issue to Feds?
Senior Member
Joined: 08-06-2007
Posts: 359
From: Edison, NJ
As mentioned above - when a rotor warps, it does not "unwarp" - the damage is done. But it does make me wonder if the stock HHR rotors undergo some kind of temporary deflection when temperatures get high enough for long enough - it only takes a few thousandths of an inch to cause a bone-jarring pulsation that gets transmitted through the brake pedal and steering column. If such a deflection could occur, it would be on account of a lack of sufficient mass to dissipate the heat, or the metallurgical assay of the steel would reveal an anomaly in the elemental composition.
In any case - such problems with braking systems on modern vehicles really should not happen, even for less expensive models such as the HHR. I suppose that the designers figured that brake pulsation is more of an annoyance than a true safety issue.
Risk management is the name of the game. Corporations are the winners and consumers are the losers.
In any case - such problems with braking systems on modern vehicles really should not happen, even for less expensive models such as the HHR. I suppose that the designers figured that brake pulsation is more of an annoyance than a true safety issue.
Risk management is the name of the game. Corporations are the winners and consumers are the losers.
Member
Joined: 04-27-2009
Posts: 53
From: GRIFFIN GA.
Brakes
Oh well, let me put my 2 cents worth in. Bought an 08 hhr 5 months ago, it had 28000 miles on it. Now it has 30500 miles on it. I dont drive it much but the brakes work fine, no chatter or pulsing. I hope it stays that way. I was spoiled with a gmc jimmy i bought new in 2000. It had 100000 miles on it when i put the first set of pads on it and 202000 miles on it when i traded it in on my hhr. Never had any brake problems with the jimmy. I hope the hhr does as good as the jimmy. I guess its just like everything. You get some good ones and you get some bad ones.
Good luck.
Good luck.
Senior Member
Joined: 07-05-2008
Posts: 5,464
From: Akron Ohio
I will present this just to bring some fact few consider and not to start anything.
#1 most time the problem is hot rotors that have some of hte brake material bonding to it once you stop. Average to low quality pads can leave material on the surface as you clamp down on a rotor at a dead stop when rotors are at their hottest.
Often once they cool and step on the brake it will clean them off. The friction on the rotor will change as you step on them as long as the material is adheared to the rotor. This will account for the rotors that cure themselves.
Rotors can warp but once they are gone they don't return, Most metals do not have memorey.
Higher quality pads will often correct this as they will not leave any material on the rotor. EBC have proven not to be prone to this as they use Dupont Kevlar and other good materials others fail to use. There is also no metal in EBC pads to transfer the heat and work as filler. Most name brand pads will have metals and brass in them that can leave deposits on the rotors.
Also driving styles can make pad leave more material on hot rotors. Note not everyone has this issue but we all do not drive the same way. The harder you drive the more prone that this condition can happen.
Also note often this condititon has gone away with better pads. It has for me and many others here and to the many of my customers.
Now here for the controversy.
If you want drilled and vented rotor by all means put them on as they look great! I have a set on the wifes car. But if you are only doing it to reduce heat save your money. You pads are what transfer heat no the rotor. The rotor works as a heat sink so the more holes you have the less metal you have and the smaller the heat sink.
In th past the main reason to drill and yet today is to remove unsprug weight. In other words to make them lighter and the vehicle handel better.
Why do they sell so many vented and dimpled rotors today. To make a buck from people who want them.
I have sat at same table with the owner and founder of ESC and also sat in on traing with Willwood, Baer, Hawk and Stainless Steel Brake and they all will tell you drilled rotors will not help in brake cooling. Slotted may help in wet and mud to clean the rotor but nothing else. It is all cosmetic. If you do not want to beleive me most brake companies have this in their tech info on their web sites. I know Willwood has it on their as I read it not too long ago.
Old tales die hard and brakes a very simple and misunderstood part.
I think the issue with todays cars can mostly go back to just cheap pads from the factory and parts stores. Like tires you pay more you get more tire same for brskes you put on $17 pads you get $17 pads.
GM puts on cheap tires on most vehicles just as they do tires and we can expect poor results than if you just upgrade the material.
We may see ceramic brakes on cheaper cars in the future. Serveral companies are working on it and they hope to bring the cost down. Have you priced the brakes for a ZR1? I been told thousands but to be fair they will last a very long time. You weight the rotors to see if they are worn out and need replaced.
Also some systems today also control the brakes well. THe GTP GP from 04 and up has a Bosh electronis balance system that give better braking and wear. My wife is hard on brakes and got 65,000 miles in the city and I have seen others get up to 75,000 miles.
Anyway agree or not this is not my opinion. It is what shown in tech classes with some of the best pad companies around smomething to consider.
Yes over tightening lugs can warp too and it will not go away either.
#1 most time the problem is hot rotors that have some of hte brake material bonding to it once you stop. Average to low quality pads can leave material on the surface as you clamp down on a rotor at a dead stop when rotors are at their hottest.
Often once they cool and step on the brake it will clean them off. The friction on the rotor will change as you step on them as long as the material is adheared to the rotor. This will account for the rotors that cure themselves.
Rotors can warp but once they are gone they don't return, Most metals do not have memorey.
Higher quality pads will often correct this as they will not leave any material on the rotor. EBC have proven not to be prone to this as they use Dupont Kevlar and other good materials others fail to use. There is also no metal in EBC pads to transfer the heat and work as filler. Most name brand pads will have metals and brass in them that can leave deposits on the rotors.
Also driving styles can make pad leave more material on hot rotors. Note not everyone has this issue but we all do not drive the same way. The harder you drive the more prone that this condition can happen.
Also note often this condititon has gone away with better pads. It has for me and many others here and to the many of my customers.
Now here for the controversy.
If you want drilled and vented rotor by all means put them on as they look great! I have a set on the wifes car. But if you are only doing it to reduce heat save your money. You pads are what transfer heat no the rotor. The rotor works as a heat sink so the more holes you have the less metal you have and the smaller the heat sink.
In th past the main reason to drill and yet today is to remove unsprug weight. In other words to make them lighter and the vehicle handel better.
Why do they sell so many vented and dimpled rotors today. To make a buck from people who want them.
I have sat at same table with the owner and founder of ESC and also sat in on traing with Willwood, Baer, Hawk and Stainless Steel Brake and they all will tell you drilled rotors will not help in brake cooling. Slotted may help in wet and mud to clean the rotor but nothing else. It is all cosmetic. If you do not want to beleive me most brake companies have this in their tech info on their web sites. I know Willwood has it on their as I read it not too long ago.
Old tales die hard and brakes a very simple and misunderstood part.
I think the issue with todays cars can mostly go back to just cheap pads from the factory and parts stores. Like tires you pay more you get more tire same for brskes you put on $17 pads you get $17 pads.
GM puts on cheap tires on most vehicles just as they do tires and we can expect poor results than if you just upgrade the material.
We may see ceramic brakes on cheaper cars in the future. Serveral companies are working on it and they hope to bring the cost down. Have you priced the brakes for a ZR1? I been told thousands but to be fair they will last a very long time. You weight the rotors to see if they are worn out and need replaced.
Also some systems today also control the brakes well. THe GTP GP from 04 and up has a Bosh electronis balance system that give better braking and wear. My wife is hard on brakes and got 65,000 miles in the city and I have seen others get up to 75,000 miles.
Anyway agree or not this is not my opinion. It is what shown in tech classes with some of the best pad companies around smomething to consider.
Yes over tightening lugs can warp too and it will not go away either.
Senior Member
Joined: 10-09-2008
Posts: 105
From: Illinois
A note about heat displacement:
The more surface area any given material has, the faster heat will be disipated. A brake rotor is 2 basic objects in 1. - 1) Brakes act as a form of friction to slow a vehicle, and 2) the fins between rotor surfaces act as a fan to draw cool air in from around the spindle/axle and force it outward towards the inside of the rim.
Now while slotting a rotor functions as a cleaning device to eliminate brake pad 'glazing', it offers little in terms of cooling, but on the other hand drilling rotors allows for more air flow to enter the cooling fins between pad surfaces. HOWEVER, since there is less material in the rotor, this tends to weaken the overall structure, and if the drilled rotors are cheaply made, may cause premature failure. Quality drilled rotors have been designed that the holes drilled will ulitmately cool the rotor with uniform heat displacement in order to prevent overbrake heat warping.
Quality of materials here is key as not all rotors, slotted or not, are made equal. A lot can be said about the pads being used as well. If you had the best (hands down proven) rotors that could ever be bought, and you use the cheapest pads you can find, then what you will find is that your pads will cause those very nice rotors to deteriorate much faster through poor design and materials.
Disk brakes are a 3 part component: calipers, pads, and rotors. Cheap out on any of those components and the whole system will be comprimised. Drum brakes are a little more forgiving as they have far more surface area to slow down a vehicle which reduces the amount of wear and tear to the friction surfaces. This, however, requires more force to be applied for like effectiveness.
To stay on topic with the original post, I have about 9500 miles on my 09 HHR LS and have not experienced warpage, however, the HHR I bought my mother is an 06 LT with about 45-50K miles and IS experiencing vibrations while brakes are applied. One of the things the dealership disclosed prior to purchase (while still under manufacturers warranty) was that the brakes had been serviced (pads/rotors/drums/shoes). That did not draw any flags as 2 years with 40K miles of stop/go traffic wears things out so I took it as a bonus- new brakes great
. That also was well before I read on these forums all the problems with rotor warpage! Since the vehicle should still be under warranty, I will look into this as I am in agreeance that brakes under normal usage should last for quite a while. When I purchase a used vehicle, I always replace the rotors/pads/drums/shoes so I KNOW what condition the braking system is in, and if necessary, service the calipers and drum pistons.
In the 20+ vehicles that I have owned, not once have the rotors warped, even buying the $35 cheapo's with the $20 cheapo pads. Now this is not to say they lasted a long time, they wore out pretty quick- 25-30K miles, 35K at most. Some of the vehicles I got rid of still had quite a bit of meat left on the pads so to 'hit the nail on the head' as to whats what comes down to how you drive for the equipment that you have. A grocery getter isnt a sports car, a sports car isnt a tank, and a tank isnt a grocery getter
The more surface area any given material has, the faster heat will be disipated. A brake rotor is 2 basic objects in 1. - 1) Brakes act as a form of friction to slow a vehicle, and 2) the fins between rotor surfaces act as a fan to draw cool air in from around the spindle/axle and force it outward towards the inside of the rim.
Now while slotting a rotor functions as a cleaning device to eliminate brake pad 'glazing', it offers little in terms of cooling, but on the other hand drilling rotors allows for more air flow to enter the cooling fins between pad surfaces. HOWEVER, since there is less material in the rotor, this tends to weaken the overall structure, and if the drilled rotors are cheaply made, may cause premature failure. Quality drilled rotors have been designed that the holes drilled will ulitmately cool the rotor with uniform heat displacement in order to prevent overbrake heat warping.
Quality of materials here is key as not all rotors, slotted or not, are made equal. A lot can be said about the pads being used as well. If you had the best (hands down proven) rotors that could ever be bought, and you use the cheapest pads you can find, then what you will find is that your pads will cause those very nice rotors to deteriorate much faster through poor design and materials.
Disk brakes are a 3 part component: calipers, pads, and rotors. Cheap out on any of those components and the whole system will be comprimised. Drum brakes are a little more forgiving as they have far more surface area to slow down a vehicle which reduces the amount of wear and tear to the friction surfaces. This, however, requires more force to be applied for like effectiveness.
To stay on topic with the original post, I have about 9500 miles on my 09 HHR LS and have not experienced warpage, however, the HHR I bought my mother is an 06 LT with about 45-50K miles and IS experiencing vibrations while brakes are applied. One of the things the dealership disclosed prior to purchase (while still under manufacturers warranty) was that the brakes had been serviced (pads/rotors/drums/shoes). That did not draw any flags as 2 years with 40K miles of stop/go traffic wears things out so I took it as a bonus- new brakes great
. That also was well before I read on these forums all the problems with rotor warpage! Since the vehicle should still be under warranty, I will look into this as I am in agreeance that brakes under normal usage should last for quite a while. When I purchase a used vehicle, I always replace the rotors/pads/drums/shoes so I KNOW what condition the braking system is in, and if necessary, service the calipers and drum pistons.In the 20+ vehicles that I have owned, not once have the rotors warped, even buying the $35 cheapo's with the $20 cheapo pads. Now this is not to say they lasted a long time, they wore out pretty quick- 25-30K miles, 35K at most. Some of the vehicles I got rid of still had quite a bit of meat left on the pads so to 'hit the nail on the head' as to whats what comes down to how you drive for the equipment that you have. A grocery getter isnt a sports car, a sports car isnt a tank, and a tank isnt a grocery getter
Thread Starter
Senior Member
Joined: 10-17-2007
Posts: 113
From: E TN
from another forum
My problem ocured after a weekend stay at a B&B in the mountains of NC. The B&B had a mile plus dirt and sand drive. Recently, I drove my mothers Buick in Florida on sand roads and it now exhibits the same problem albiet not as bad. Seems to be a design feature on GM cars. Have others who have brake problems been driving on unpaved roads?
Big Kahuna- 04-14-2008
Here is the bulletin about brake pulsation and the splash shields as promised in another post....will also post it there.. #08-05-23-003: Front Brake Noise, Brake Pulsation, Front Brake Inner Pad Wear (Replace Front Brake Pads and Add Splash Shields) - (Mar 20, 2008) Subject: Front Brake Noise, Brake Pulsation, Front Brake Inner Pad Wear (Replace Front Brake Pads and Add Splash Shields) Models: 2006-2008 Chevrolet HHR -------------------------------------------------------------------------------- Condition Some customers may comment on a brake noise and/or pulsation on brake apply. This condition can be more frequent if the customer resides or travels on dirt/gravel roads and usually occurs within 11,300 km (7,000 mi) to 16,000 km (10,000 mi) intervals. Upon investigation, the technician may find that there is considerable difference between the front brake outer and inner pad thickness. Cause This condition may be due dust, dirt, and debris intruding between the inner brake pad and rotor. Correction Road -*test*-('") the vehicle and confirm that the brake noise and/or pulsation is coming from the front brakes. If it is determined that the noise is coming from the front brakes and there is a measurable difference between the outer and inner pad thickness, remove the front wheel bearing/hub assembly following published SI procedures, remove the bearing/hub-to-steering knuckle spacer and replace the spacer with a splash shield on each side. Replace the front brake pads and follow the procedures outlined in Service Bulletin 00-05-22-002J for servicing the disc brake rotors. Parts Information Part Number Description Qty 25884778 Shield, Front Brake (Right) 1 25884779 Shield, Front Brake (Left) 1
Big Kahuna- 04-14-2008
Here is the bulletin about brake pulsation and the splash shields as promised in another post....will also post it there.. #08-05-23-003: Front Brake Noise, Brake Pulsation, Front Brake Inner Pad Wear (Replace Front Brake Pads and Add Splash Shields) - (Mar 20, 2008) Subject: Front Brake Noise, Brake Pulsation, Front Brake Inner Pad Wear (Replace Front Brake Pads and Add Splash Shields) Models: 2006-2008 Chevrolet HHR -------------------------------------------------------------------------------- Condition Some customers may comment on a brake noise and/or pulsation on brake apply. This condition can be more frequent if the customer resides or travels on dirt/gravel roads and usually occurs within 11,300 km (7,000 mi) to 16,000 km (10,000 mi) intervals. Upon investigation, the technician may find that there is considerable difference between the front brake outer and inner pad thickness. Cause This condition may be due dust, dirt, and debris intruding between the inner brake pad and rotor. Correction Road -*test*-('") the vehicle and confirm that the brake noise and/or pulsation is coming from the front brakes. If it is determined that the noise is coming from the front brakes and there is a measurable difference between the outer and inner pad thickness, remove the front wheel bearing/hub assembly following published SI procedures, remove the bearing/hub-to-steering knuckle spacer and replace the spacer with a splash shield on each side. Replace the front brake pads and follow the procedures outlined in Service Bulletin 00-05-22-002J for servicing the disc brake rotors. Parts Information Part Number Description Qty 25884778 Shield, Front Brake (Right) 1 25884779 Shield, Front Brake (Left) 1
Last edited by jdmcomp; Jul 3, 2009 at 02:49 PM. Reason: more info
Senior Member
Joined: 07-17-2006
Posts: 6,053
From: Dallas, GA
Good luck in your quest.... But,
Please describe "normal service"? Most of the people I encounter in the Atlanta area are very hard on the brakes, I know that is not "normal service", more "severe duty".
Those that are easy on the brakes, seems to not have problems with warping. Since I moved last summer to this area, I know I'm harder on my brakes as well. I get the occasional shimmy now. I'm going to check mu lugs tonight before my road trip to Asheville this weekend. Will see if that helps.
Once again, good luck.
Please describe "normal service"? Most of the people I encounter in the Atlanta area are very hard on the brakes, I know that is not "normal service", more "severe duty".
Those that are easy on the brakes, seems to not have problems with warping. Since I moved last summer to this area, I know I'm harder on my brakes as well. I get the occasional shimmy now. I'm going to check mu lugs tonight before my road trip to Asheville this weekend. Will see if that helps.
Once again, good luck.
Member
Joined: 05-28-2008
Posts: 43
From: Schenectady New York
Ok... I dodnt mean to steal this thread so moderators if it appears this way could you move it to a thread of its own. I want to make an inquiry. I bought my 07 with 8,000 miles on it last spring (april) now with 32,000 my steering wheel shakes like crazy when braking after being driven a while. I agree with the above posting ... when its just taken out for a run it does not shake at all. As driviing continues it begins and keeps getting worse until, like above Im discussed with it. I have been watching the brake discussion on this and the other blog. I think I am correct in surmizing that the best way for me to eliminate the problem is to replace the rotors and brakes but didn't consider replacing the calipers. Could someone point me to those discussion threads or someone whom made their braking problems go away please email me or post their purchasing choises. Obviously by the mileage I put on my car I love driving it but the shaking while braking has got to stop. My fiancee wants me to take it to the dealer but I doubt it (brakes) are a waranteed repair. I probably will buy the parts and find a private jobber to do the work. Thanks for any help you can provide.
Senior Member
Joined: 02-16-2009
Posts: 6,038
From: Frankenmuth/Flint, MI
Lets not get personal shall we? I have owned and driven many cars. I have put 100's of thousands of kilimeters on them and I have had rotors warp on other vehicles. It is a simple fact of life. I'd love to see a set of rotors that lasted 200000 miles. Must never had to use the brakes. Rotors warp and the more economical the car the more often it happns. It is just the way things are IMO. If you want those super beefed up rotors, fine get them, but do you really expect a car company to put the Best of everything on a very cheap ride? I don't and I expect to get what I paid for. I paid for a sub $15000 car and so expect those issues. Makes sense to me. They seem to perform fine for me and I drive over 100 miles a day back and forth to work in bumper to bumper and stop and go traffic.
New Member
Joined: 01-06-2007
Posts: 16
From: Indianapolis,In.
Ive got 47,000 mi. on an 07 and have had the shimy prob since it was new.It is such a common problem with these cars I have to believe its bad metal . Im going to try to get 60,000 on them and then new pads, rotors and tires. Hope that solves the prob.
Joined: 07-09-2009
Posts: 4
From: NE Ohio
While reading this forum I have noticed this issue of brake pulsation. From my personal experience with an 03 Saturn Ion (195,000mi of ownership), I only had 1 experience with brake pulsation that I was able to directly relate to improper lugnut tightening. I had a tire rotation done at an unfimiliar shop. The pulsation started within 3000mi of the tire rotaion. When I checked into the vibration by checking the torque of the lugnuts I found there were a few that were real easy to remove and atleast 1 that required a breaker bar with a 4ft pipe extension added to the end of it.
After that occurance, I required, and checked to make sure that the tire shop ALWAYS hand torqued the lugnuts. The first occurance happened around 30-35000mi.
Actually GM has a service bulletine that addresses this issue.
DOC ID 1860939
Excerpt:
Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Use the J 39544-KIT, or the equivalent torque stick, in order to tighten the nuts with an impact wrench. When running the nuts down the studs, run the impact wrench at a reasonable speed. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration.
Even with correct torque a problem could be caused by Corrosion as also listed in the same bulletin:
Corrosion:
One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition.
Caution: Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury.
Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface.
The J 41013, or equivalent can be used to clean the following surfaces:
• The hub mounting surface
• The brake rotor mounting surface
• The wheel mounting surface
Kurt
09 HHR LS
After that occurance, I required, and checked to make sure that the tire shop ALWAYS hand torqued the lugnuts. The first occurance happened around 30-35000mi.
Actually GM has a service bulletine that addresses this issue.
DOC ID 1860939
Excerpt:
Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Use the J 39544-KIT, or the equivalent torque stick, in order to tighten the nuts with an impact wrench. When running the nuts down the studs, run the impact wrench at a reasonable speed. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration.
Even with correct torque a problem could be caused by Corrosion as also listed in the same bulletin:
Corrosion:
One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition.
Caution: Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury.
Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface.
The J 41013, or equivalent can be used to clean the following surfaces:
• The hub mounting surface
• The brake rotor mounting surface
• The wheel mounting surface
Kurt
09 HHR LS
