GMT-900 Brakes

[vtelvr]

I have an appointment set for Saturday with the dealership to have my brakes checked out. Had to get down on them pretty good the other day on the highway, doing near 70mph. Just about shook my hands off of the wheel. Warped rotors I am assuming...12,500miles on my damn truck, and brakes already?!?! Oh well. I will give them one shot to do it right, then its my turn. I will go aftermarket pads and rotors...

 

Oh yeah, with a full towing package, WHY THE FK DO I HAVE DRUM BRAKES?!?!?! Damn you GM!

[2016 Sierra Owner]

Have a look at this post.

 

Why Do I Have Drum Brakes?

[vtelvr]

Have a look at this post.

 

Why Do I Have Drum Brakes?

 

I have thumbed through that thread...its ridiculous...There is no reason any vehicle being produced now days should have damn drum brakes.

[DTyrrell]

Haven't had a problem with my brakes, and you make it sound like GM is the only company to put drum brakes on their vehicles. I'm pretty sure in that other post they went on about how semi's are still using drums, and how the rear brakes don't do nearly the amount of braking as the front. I was always told the rear brakes are mostly just there to prevent your rear end from sliding out. My dad always used to say 80/20 (80% braking done by the front, 20 the rear), as he was taught in school, never confirmed it though.

[wtbrowne]

I'll concur with vtelvr.

[mhenshaw]

Drum brakes in the rear last longer and like everyone stated they only do 20-30% of the braking so I like my drum brakes better.

 

As far as the front it seems GM doesn't use quality brake rotors anymore and they seem to be wraping easily. Save yourself the hasel and buy some quality rotors that are built to disipate heat and gases. I use mine offen due to Memphis rush hour traffic. I stop better than a lot of older cars.

[ChevyTech77]

The drum brakes are fine and stop quite well so relax. Side by side testing confirms that they both have nearly the same stopping distances (when it was done with the GMT-800 trucks in 04-05).

 

There are alot of factors that go into wether your front brake rotors are going to warp or not on these trucks. I've

seen trucks in for their first set of pads at 60k with no brake pulsation what-so-ever and I've seen them in with 5-10K with the rotors warped beyond belief. Geographic location and driving habits have EVERYTHING to do with it.

[aj47]

Pickup trucks are designed to haul heavy loads and pull trailers. With a load or a trailer in tow, the rear brakes do much more than 20% of the braking - more like 50% depending on circumstances. Disks aren't nearly as prone to brake fade when they're hot and they're superior in nearly every other way. Disk brakes replaced drum brakes for a reason. About the only cars you see with rear drums are economy cars where costs are a major concern to the manufacturer.

[mhenshaw]

Pickup trucks are designed to haul heavy loads and pull trailers. With a load or a trailer in tow, the rear brakes do much more than 20% of the braking - more like 50% depending on circumstances. Disks aren't nearly as prone to brake fade when they're hot and they're superior in nearly every other way. Disk brakes replaced drum brakes for a reason. About the only cars you see with rear drums are economy cars where costs are a major concern to the manufacturer.

 

 

Is that why Semi Trucks who haul nothing but loads use drum brakes? Drum brakes are better for towing due to they have more surface area for the brake pads to contact the drum. I think if Disks where so much better for towing they would be on big rigs that drive the highways all day long.

 

I believe both have their advantages and disadvantages like drums holding mud. But there is no reason to complain about them being on the back of your truck.

[vtelvr]

I can't believe that someone in R&D at GM decided that when the truck is loaded to its capacity thought that it would be a good idea to save on brakes. WTF were they thinking? Ok, It saves a buck or two. It is a tried and true design. Ok. Well, both of those factors can be overcome. The cost savings is null as the interior fabric SUCKS. The tried and true part, I can understand that. However, with auto companies going to better and more efficient braking, why would you take a step backwards?

 

 

Sorry for the rant. Just can't understand some things.

[2016 Sierra Owner]

Geographic location and driving habits have EVERYTHING to do with it.

 

I have to agree with you on this. I had an 01 2500 HD with disk brakes all around. I can't tell the difference between it and my 09 1500 stops the same to me. I still had over 50% pad left when I traded it in with 76,000 on the clock. I had a guy at work ask me one time who could replace his brake pads. He has a 02 or 03 RC 1500 with the step side bed. His brakes were worn out at 45,000ish. I told him there was no way as my truck weights a good 500 to 1000 LBS more than his and I still had great breaks. He does not tow anything and neither do I. The only thing it could come down to was our driving habits being different. Grant it he had front disk and rear drums but, I do not think that had anything to do with it.

[txab]

[HapHazard]

Since purchasing my GMT 900 Silverado I have noticed that a shimmy on downhill braking. This last weekend I noticed a HEAVY front end shake and shimmy when applying the brakes going down the Grapevine into the San Joaquin Valley. At the shop today, they confirm that my front rotors are in need of resurfacing, and asked me questions about whether I have towed something, etc., in essence implying that I had done something to cause this anomaly. It would have been okay, and I answered the questions (I have never towed anything), but at the end of the conversation, the service writer informed me that the resurfacing is NOT a warranty item because I have more than 11,000 miles on the vehicle.

 

Along with not placing rotors on the rear wheels, which I contend may hvae something to do with the rotor problems on the front, the fact that GM can exclude rotors after 11,000 miles (unless they need total replacement) is insulting and makes me wish that I still owned my 2004 F-150. I actually had a rotor problem on that vehicle, after 28,000 miles, and the dealer replaced all 4 rotors at no cost.

 

Weak.

[ChevyTech77]

Since purchasing my GMT 900 Silverado I have noticed that a shimmy on downhill braking. This last weekend I noticed a HEAVY front end shake and shimmy when applying the brakes going down the Grapevine into the San Joaquin Valley. At the shop today, they confirm that my front rotors are in need of resurfacing, and asked me questions about whether I have towed something, etc., in essence implying that I had done something to cause this anomaly. It would have been okay, and I answered the questions (I have never towed anything), but at the end of the conversation, the service writer informed me that the resurfacing is NOT a warranty item because I have more than 11,000 miles on the vehicle.

 

Along with not placing rotors on the rear wheels, which I contend may hvae something to do with the rotor problems on the front, the fact that GM can exclude rotors after 11,000 miles (unless they need total replacement) is insulting and makes me wish that I still owned my 2004 F-150. I actually had a rotor problem on that vehicle, after 28,000 miles, and the dealer replaced all 4 rotors at no cost.

 

Weak.

Rotor replacement due to corrosion or damage (brake drag causing pads to wear out and metal to metal contact) IS covered under GM warranty. Brake pulsation is officially NOT covered after 12 months/12,000 miles. Chrysler and Ford are the exact same way. I've never turned down, and have never been charged back from GM, for brake pulsation warranty repairs past the 12/12 up to 3/36. It's all in the dealer's hands really.

 

BTW, if you are driving in hilly/mountainous area's, most every vehicle (depending on weight and use of course) will

warp brake rotors if you don't downshift the transmission in order to assist the brake system. If you ride the brakes, like what can be done coming down a mountain grade, on flat roads, the rotors will warp from heat too.

[revrnd]

I can't believe that someone in R&D at GM decided that when the truck is loaded to its capacity thought that it would be a good idea to save on brakes.

 

In the past I've seen a linkage actuated brake proportion unit mounted between the frame & rear axle on C/K 1 tons & some Toyota pickups.

 

What percentage of 1/2 tons are loaded to the max? Does the barking average on the current trucks adjust for the load/weight of the truck?

 

My point being if GM designed the brakes for a fully loaded (weightwise) truck how would it brake when hauling 2 bags of groceries? Would the braking action be too agressive for your average soccer mom in her crew cab 1/2 ton?