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I have a 2008 3/4 crew cab with about 160K on it with the original brakes. I have noticed that running on the interstate the brakes are fine but on the back roads with a bit of braking the front rotors do feel warped after a bit of braking. A hard brake application with help with the warping but soon will feel warped again. This truck has been like this for some time and not sure if this is pretty common for the 3/4 HDs. Got quite a bit of brake pad left. Have others seen this also and if so what did you do to get rid of it all together. Thanks, Dean
 

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I have a 2008 3/4 crew cab with about 160K on it with the original brakes. I have noticed that running on the interstate the brakes are fine but on the back roads with a bit of braking the front rotors do feel warped after a bit of braking. A hard brake application with help with the warping but soon will feel warped again. This truck has been like this for some time and not sure if this is pretty common for the 3/4 HDs. Got quite a bit of brake pad left. Have others seen this also and if so what did you do to get rid of it all together. Thanks, Dean
ive warped rotors on both of my trucks but im not sure if thats a chevy issue, or a moose walking out onto the highway issue.
 

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It sounds like when you heat your braking system, you see signs that you have warped rotors, otherwise they're not warped. Right? When was the last time, if ever, you did a complete brake flush on your truck? Many people have never done one and at about 11 years old, yours may need this. As old fluid accumulates moisture and the fluid heats up, it creates 'steam' and that steam will not compress, or will compress and decompress, and your brakes may have the feel you observe. Also, I believe an automated brake flush may help your situation, removing air from your ABS system..
 

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It sounds like when you heat your braking system, you see signs that you have warped rotors, otherwise they're not warped. Right? When was the last time, if ever, you did a complete brake flush on your truck? Many people have never done one and at about 11 years old, yours may need this. As old fluid accumulates moisture and the fluid heats up, it creates 'steam' and that steam will not compress, or will compress and decompress, and your brakes may have the feel you observe. Also, I believe an automated brake flush may help your situation, removing air from your ABS system..

a brake system flush is never a bad idea, the fluid also becomes acidic over time and pickups water. I try to do it yearly, brake fluids not expensive and im a big fan of stopping when i press the brakes. If you have not done a fluid change in a while it is a good idea to do it, im not sure it will fix your problem, but it wont hurt it and the rest of the brake system will thank you for it.
 

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Discussion Starter #5
It sounds like when you heat your braking system, you see signs that you have warped rotors, otherwise they're not warped. Right? When was the last time, if ever, you did a complete brake flush on your truck? Many people have never done one and at about 11 years old, yours may need this. As old fluid accumulates moisture and the fluid heats up, it creates 'steam' and that steam will not compress, or will compress and decompress, and your brakes may have the feel you observe. Also, I believe an automated brake flush may help your situation, removing air from your ABS system..
It as been some time since the brake fluid was replaced but it truly feels like rotor warp. The steering will shimmy back and forth when it happens. Like I said when they are hot a hard brake application will help with the shimmy but only for a short time. Rotors do have some hot spots on then on the front side. I have heard that the 2500 brakes were a bit weak compared to the 3500. I will do a brake flush but not sure that will address this issue. Just not sure if the stock rotors are a problem or better brake pads. I do know ceramic brakes will cause plenty of issues with the rotors. I was just curious if others had seen this and what cleared up the issue. Dean
 

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I was having a similar warped rotor feel with my 10 year old truck. Since I bought a new, heavier trailer and I needed new front bearings, I decided to upgrade to some drilled and slotted rotors at the same time a few months ago. I did not have the brake fluid flushed with the bearing/brake replacement. With the new brakes installed, it still had the warped rotor feel under heavy braking. (As an aside, the old rotors and pads still had lots of life in them and the old rotors did not look warped after about 150k miles.)

Any vehicle I have had that warped rotor fee in the past actually had warped rotors. I will replace the brake fluid and see if that fixes the warped feel. Thanks for the tip Ron.
 

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Dean - The only way you will really ever know is to take a rotor to the machine shop and ask them to check it, or turn it, and see what the measurements tell you. You can decide to fully true the rotor, or decide that you'd rather have new. In any case, you will know what you are dealing with.
 

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Ron is correct with water not compressing and steam compressing as the fluid heats up creating a "surge" or "pulse" in the system. Another thing to consider are the types of pads used and what is done after the brakes are heated up. Cheap pads can leave imprints/material on the rotor causing the same feeling as a warped rotor. The other issue is driving the brakes hard and shutting down the truck or stopping for a prolonged time creating a hot zone under the pads while the rest of the rotor cools faster.
 

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It is a 10 minute process to check run-out on the rotors and verify that they are warped. I had warped rotors on my Tahoe at only 28,000 miles. I replaced them with non-GM rotors and had no more problems for the next 150,000 miles and had sold the Tahoe.
 

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Good idea to change but your problem is not your brake fluid. I just dealt with similar situation on my 2012 with 120k mi. Braking unloaded is perfectly fine but coming down grades with my 5er if I didn’t have my EB engaged things would turn bad in a hurry. As the brakes heated the pulsating and fade in the brakes would get worse and worse.

Took it in a few weeks ago and they said the front rotors had heat cracks in them. Had new front rotors and pads installed and just recently did 1000mi towing and brakes were back to what they use to be.
 

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I'm a fan of the brake fluid flush, but do not think that is your problem. I have heard this issue referred to as rotor warp or brake pad deposition. Either way, even though the rotors look good, it's time for them to go. You are likely past the practical end of life - age wise - for pads. Rotors are not that expensive. I'd go for a matched set of ceramic pads and rotors and flush the fluid and call it a day. You'll be happy you did.
By the way, I went with drilled and slotted and am not thrilled. I think I lost stopping distance. just my .02
 

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Follow up to the drilled and slotted performance comment. It makes sense the stopping power would decrease as there is less surface area for the pads to contact. The tradeoff is the brakes don't have the heat fade while descending large hills. Original brakes and old, lighter trailer, the heat fade was a regular occurrence. This year with new brakes and 25% heavier trailer, I did not notice the heat fade.
For all the mountain passes I tow through in BC and Washington, cool brakes are more important to me than slightly longer stopping distances. (And I haven't really noticed longer stopping distances in general use) That's my five cents worth since we don't have pennies in Canada anymore.
 

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There is also the tradeoff that the drilling and slotting process can create stress risers in the rotor resulting in cracking. I was always under the impression that slotting the rotor was for track use, as it helped prevent pad glazing by shaving the pads down slightly, and the drilling process was to allow gases from the pads offgassing at high temps to pass into the rotor vanes rather than building up under the pad and causing a loss of braking power. Modern pads dont off gas like old pads do, so the drilling is less important and i would probably not run slotted rotors for street use since there more likely to chew through pads. That said, if the trucks used under some extreme applications the slotted drilled rotors might be a tradeoff worth making even with the theoretically lower service life of them and the pads. For general use though, the standard solid rotors give you more surface area to brake with, and make for a stronger rotor with fewer stress points to propagate a crack.

 

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Discussion Starter #15
Sorry, been too busy with work to spend any time on the forum. I did do the fluid flush and to no surprise there was no difference in the braking issue. I have been researching this on the web and found this fairly common for the LMM series of HD trucks. The LML went to a bigger rotor that what the LMM has. Not a fan of the ceramic pads. While they do keep rotor dust down they do not absorb heat at all which puts more heat in the rotors and will cause them to warp easier. The pads on mine look great yet but I might be going ahead some time this winter and changing them and the rotors to see things go. Needless to say I won't be getting my rotors from Autozone or such. Probably will go with Napa unless someone has a brand they recommend and no drilled rotors. Dean
 

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Mine got all potato chippy at 85K with occasionally towing and empty driving. After being turned once, they made it another 10K. Then I the warping got bad again on a long trip with 1200 pounds in the bed.

It now has 4x cross- drilled , ventillated rotors and ceramic pads. The whoa pedal works good now.
 

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Mine got all potato chippy at 85K with occasionally towing and empty driving. After being turned once, they made it another 10K. Then I the warping got bad again on a long trip with 1200 pounds in the bed.

It now has 4x cross- drilled , ventillated rotors and ceramic pads. The whoa pedal works good now.
I forgot to say that the front rotors took turns hanging up after after the pads and rotors were replaced. I removed the pads and clearanced them on the grinder along the edges for a looser fit in the caliper. It turned out that both calipers had gotten sticky at the pistons. Whatever the case, New rotors, fully bled, new calipers and ceramic pads and stops like it should now.
 
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