A Word on the Silverado's New Braking System

**Ghrankenstein** · 08-01-2004, 03:56 AM

First off, I'll be moderating the content on this thread more strictly than I normally do. If you have a reply that's not even as long as your signature, that says nothing more than "pro" or "con," I recommend that you post it in the Discussion Area, and not the Press Room. Call it an experiment, if you must.

Now, GM hasn't been idle in addressing the move to rear drums on some of the Silverado models. They know they're the ones that butt-trumpeted so much about their 4-wheel discs, and I've certainly closed many deals because of that.

The new system will be standard on 1/2 ton models, except for the hybrids. The one variable I -don't- know is the 1500 SS, which already stops quicker than the most recent M5 (60-0 in 118 feet). The new brake system will provide both shorter stopping distances and better pedal feel.

Keep in mind, that drum brakes have improved drastically in their technology and performance in just the last few years. I'm not clear on exactly -what- that technology is, but this is what I'm told, and I'm just parroting it. The 1500's new drum brakes are the largest ever installed on a light-duty truck, and they make the new 17" wheels a necessity.

Also keep in mind the workload of front brakes vs. the rear brakes, especially on a pickup. On the 1500's, approximately 75% of the braking is done by the front brakes anyway. The cost savings of the rear drums allows for larger front rotors, with dual-piston calipers, and a new master cylinder. The end result is a better system.

I hope this clears a few things up. I'll try to get answers for any questions, or any comments that I can't address.

Your Friend,

Ghrankenstein

Erunion · 08-01-2004, 05:41 AM

All 1500s will have rear drums(with possible exception of the SS)? Or will there be any packages with rear disks?

Ultimate · 08-01-2004, 06:50 AM

wow thats pretty awesome where i can find this info on the SS stopping faster than the new M5?

jwrebholz · 08-01-2004, 06:56 AM

I'm sure 4-wheel discs will still be available, but I can't say I like this idea at all.

These are the same geniuses that thought it would be smart to make ABS an option on several models, after being the first domestic automaker (as far as I know) to have ABS standard on everything. It seems a big step backward to me to go from better technology to a fundamentally flawed one like this. I don't care how big the drums are. A drum brake can NEVER be as effective as an equivalent disc brake.

4-wheel discs aren't just a luxury or performance item, they're a safety concern as well. The less time it takes to haul that truck down, the safer it can be because it's mroe able to avoid a collision.

No, I'm sorry. This is a bad idea. GM needs to go back to standard ABS and standard 4-wheel disc brakes. I can guarantee their competitors won't backpedal if they do--making GM trucks an inferior product and giving away more market share to Ford and Dodge.

ByTheLake · 08-01-2004, 07:37 AM

This is just my observation, but given the complexity of a drum brake assembly, it seems to me that it would cost more to assemble and adjust a rear drum brake from a manufacturing perspective than it would for a disk assembly.

For manufacturers, rotors and calipers are pretty cheap in volume.

Does anybody have data on manufacturing costs of drums vs disks?

Erunion · 08-01-2004, 08:02 AM

Quote:

Originally posted by jwrebholz@Aug 1 2004, 10:56 AM
These are the same geniuses that thought it would be smart to make ABS an option on several models,

Why should I be forced to pay for something I dont want?

Thats right, I have no use for ABS. Dont have it now, dont want it later.

LynnJ · 08-01-2004, 09:41 AM

Disc brakes aren't necessarily better in every application. A tractor trailer doesn't have the first disc on it. Disc brakes don't have the required surface area to stop something that big of course we are talking at least 60,000 plus pounds. My camaros rear disc pads don't hold up anyway. Whether the truck has disc brakes on the rear or not, if the truck stops quicker and the pedal feel is better then the brake system is better. Although the public won't perceive it that way. Maybe the General should air some commercials testing their new braking system against the competitors if its better. Or maybe they are just trying to add more options to the truck such as disc brakes to help make up some of the lost revenue from the incentives black hole.

**Ming** · 08-01-2004, 10:17 AM

I'm concerned with all of the decontenting going on at Chevy (cars included). It may make sense for GM, but one has to wonder if some of it isn't to keep the vehicles profitable in the face of bigger and bigger incentives. In particular it seems the Monte Carlo and Impala had a round of decontenting last year, and I don't recall if the MSRP dropped accordingly. Eventually, to get a vehicle with the same options "standard", I'm going to have to pay 4000 bucks for an option package --- the exact cost of the rebates.

ByTheLake · 08-01-2004, 10:21 AM

Now that you mention it, the big rigs use drums, don't they? Maybe there is something 'heavy duty' about them.

If the stopping distance is there and the brake feel is good, I'll not lose sleep over this one.

HummerTech · 08-01-2004, 12:04 PM

Maybe this is their fix for the parking brake problems on the 800 truck?

impala02 · 08-01-2004, 01:33 PM

This whole disc/drum situation has me perplexed. When I first read about this I was a bit dismayed. However, some of this may be due to perception rather than performance. My first cars all had drums in the rear. At the time I was aware that more upscale cars included rear discs. Also, sports cars always have discs all around. Therefore, I was pretty happy when my past two cars came equipped with front and rear disc brakes. However, I'm not sure I've ever felt a difference in braking performance, and if there is one, that it is due to having discs mounted on the rear wheels (Larger discs up front make a big difference, as do the hydraulics). Most of the braking load is placed on the front wheels, therefore, your front brakes do most of the work when stopping your car or truck. I also know that drums last a lot longer than disc brakes and you don't have to worry about rotor warpage. I believe that it is also cheaper to service drums than discs (not sure about this though). For me though, I love the look of discs behind the rear wheels.
From a production standpoint, I would think that discs are cheaper and easier to manufacture (although almost all cars today come equipped with awful rotors that are prone to warping (not just GM!). I always thought drum brakes seemed more complex. However, I'm probably wrong as a lot of "base" cars come with drums in the rear and can be optioned with discs. Are there any direct comparisons in stopping distances of the same car, one equipped with drums and the other discs?
I can't see how adding drums would shorten stopping distances....I don't think you would ever see GM putting drums on the Corvette to get a better braking feel, or shorter stopping distances.

With that being said, have there been a lot of complaints about the current Silverado regarding the rear brakes? Not in everyday driving, but when hauling heavy loads in the bed or when trailering (what pick-ups are really meant to do)?
There has to be a logical explanation for reverting to rear drums....I just hope it does not have to do with saving a couple of bucks on each truck.

impala02 · 08-01-2004, 01:45 PM

Quote:

Originally posted by jwrebholz@Aug 1 2004, 06:56 AM
I'm sure 4-wheel discs will still be available, but I can't say I like this idea at all.

These are the same geniuses that thought it would be smart to make ABS an option on several models, after being the first domestic automaker (as far as I know) to have ABS standard on everything. It seems a big step backward to me to go from better technology to a fundamentally flawed one like this. I don't care how big the drums are. A drum brake can NEVER be as effective as an equivalent disc brake.

4-wheel discs aren't just a luxury or performance item, they're a safety concern as well. The less time it takes to haul that truck down, the safer it can be because it's mroe able to avoid a collision.

No, I'm sorry. This is a bad idea. GM needs to go back to standard ABS and standard 4-wheel disc brakes. I can guarantee their competitors won't backpedal if they do--making GM trucks an inferior product and giving away more market share to Ford and Dodge.

Not sure if you are talking about all GM products here or just the trucks...but the Silverados WILL all have ABS, according to the info released by NSAP. I agree with you though that they should stick to 4 wheel disc brakes though.

Did GM have ABS standard on all models? I know they removed it as standard equipment on some models, but I didn't think that it was ever standard on every model.

Sorry to stray from the content of this forum but, as far as safety goes, ALL cars and trucks should have ABS and side airbags as standard equipment.

sheithappens · 08-01-2004, 02:07 PM

http://www.alldata.com/techtips/2004/20040308c.html

Jim Grant's Tech Tips

'02 Chevy Silverado, Brake Eater

Q: My ’02 Chevy Silverado K1500 eats the right rear brakes. The truck has only 43k miles and I’m now on my third set of rear brakes. I had to replace the right rear brake rotor at 18k because I didn’t hear the brake pads grinding and it damaged the rotor. The truck didn’t even make it to 30k miles when the right rear brake was worn out again. Now with 43k I am looking at another brake job on the rear. The front brakes look like new and the left rear was never more then 75% worn, but was replaced each time when the right rear brake was replaced. The mechanic says this is a problem with GM trucks and that it doesn’t matter what brand of brake pads I have put on it will still wear. What’s the deal? Doesn’t GM know how to build trucks that don’t eat up brakes?!

A: Oh yes, that infamous right rear brake pad problem. GM has had a problem with the rear brakes on their light duty trucks. There is a fix. The ALLDATA Information System shows GM Technical Service Bulletin # 00-05-23-005B, which to simply describe is a mud flap kit. This kit addresses rapid brake pad wear problem that is found on most GMC and Chevy trucks made from ’99 to ’04. The right rear brake caliper and pads are located in such a manner that road dirt flies right into the brake pads. This steady diet of dirt causes the brakes pads to wear out really fast. The GM mud flap kit is installed to block bombardment of road dirt and debris that is causing the brake pads to wear out so quickly. The GM kit part number is 15765007 and is pretty easy to install. Before your next brake job I would suggest installing the mud flat kit. I think if you check with your dealership they be very agreeable to install the mud flap kit.

**Ghrankenstein** · 08-01-2004, 03:31 PM

Quote:

wow thats pretty awesome where i can find this info on the SS stopping faster than the new M5?

Not the new V-10 M5, but the most recent one. I got that info from the stats pages from C&D, MT, or R&T, can't remember which, but I didn't cross-match the scores either. The SS stopped in 118 feet, the M5 stopped in 120. Probably not C&D, since they usually test 70-0.

Ghrank

ewm2 · 08-02-2004, 08:55 AM

It is amazing that so many people on this board are saying, "GM is decontenting and taking off rear disks on their trucks" rather than saying that if the press is true and the breaks on the trucks have been greatly improved it will be nice. The reason they decontented the rear is so that they could improve the front breaks (that do 75% of the stopping) and therefore improving the performance of the truck.

08-01-2004, 03:56 AM	#1 (permalink)
Ghrankenstein GMI Staff Member Join Date: Jan 2003 Location: Springfield, MO Drives: 2004 Chevy Cavalier LS Sport 5-speed. Posts: 3,169	First off, I'll be moderating the content on this thread more strictly than I normally do. If you have a reply that's not even as long as your signature, that says nothing more than "pro" or "con," I recommend that you post it in the Discussion Area, and not the Press Room. Call it an experiment, if you must. Now, GM hasn't been idle in addressing the move to rear drums on some of the Silverado models. They know they're the ones that butt-trumpeted so much about their 4-wheel discs, and I've certainly closed many deals because of that. The new system will be standard on 1/2 ton models, except for the hybrids. The one variable I -don't- know is the 1500 SS, which already stops quicker than the most recent M5 (60-0 in 118 feet). The new brake system will provide both shorter stopping distances and better pedal feel. Keep in mind, that drum brakes have improved drastically in their technology and performance in just the last few years. I'm not clear on exactly -what- that technology is, but this is what I'm told, and I'm just parroting it. The 1500's new drum brakes are the largest ever installed on a light-duty truck, and they make the new 17" wheels a necessity. Also keep in mind the workload of front brakes vs. the rear brakes, especially on a pickup. On the 1500's, approximately 75% of the braking is done by the front brakes anyway. The cost savings of the rear drums allows for larger front rotors, with dual-piston calipers, and a new master cylinder. The end result is a better system. I hope this clears a few things up. I'll try to get answers for any questions, or any comments that I can't address. Your Friend, Ghrankenstein __________________ NEW RIDE: 2008 Carp Poseidon (for fish-head delivery)

08-01-2004, 06:56 AM	#4 (permalink)
jwrebholz 6.0 Liter Vortec V8 Join Date: May 2004 Location: Pittsburgh, PA Drives: 2001 Chevy Cavalier Posts: 1,588	I'm sure 4-wheel discs will still be available, but I can't say I like this idea at all. These are the same geniuses that thought it would be smart to make ABS an option on several models, after being the first domestic automaker (as far as I know) to have ABS standard on everything. It seems a big step backward to me to go from better technology to a fundamentally flawed one like this. I don't care how big the drums are. A drum brake can NEVER be as effective as an equivalent disc brake. 4-wheel discs aren't just a luxury or performance item, they're a safety concern as well. The less time it takes to haul that truck down, the safer it can be because it's mroe able to avoid a collision. No, I'm sorry. This is a bad idea. GM needs to go back to standard ABS and standard 4-wheel disc brakes. I can guarantee their competitors won't backpedal if they do--making GM trucks an inferior product and giving away more market share to Ford and Dodge. __________________ Secret member of the VAST RIGHT-WING CONSPIRACY. (Ssh! Don't tell anybody!)

08-01-2004, 10:17 AM	#8 (permalink)
Ming GMI Staff Member Join Date: Jan 2003 Location: SE Texas Posts: 13,430	I'm concerned with all of the decontenting going on at Chevy (cars included). It may make sense for GM, but one has to wonder if some of it isn't to keep the vehicles profitable in the face of bigger and bigger incentives. In particular it seems the Monte Carlo and Impala had a round of decontenting last year, and I don't recall if the MSRP dropped accordingly. Eventually, to get a vehicle with the same options "standard", I'm going to have to pay 4000 bucks for an option package --- the exact cost of the rebates. __________________ The Latest: Step by Step - How to Play Commodore 64 Games on a PC

08-01-2004, 01:33 PM	#11 (permalink)
impala02 3.8 Liter Supercharged V6 Join Date: Jan 2003 Location: CT Drives: 2002 Chevy Impala 2008 Chevy Equinox Posts: 747	This whole disc/drum situation has me perplexed. When I first read about this I was a bit dismayed. However, some of this may be due to perception rather than performance. My first cars all had drums in the rear. At the time I was aware that more upscale cars included rear discs. Also, sports cars always have discs all around. Therefore, I was pretty happy when my past two cars came equipped with front and rear disc brakes. However, I'm not sure I've ever felt a difference in braking performance, and if there is one, that it is due to having discs mounted on the rear wheels (Larger discs up front make a big difference, as do the hydraulics). Most of the braking load is placed on the front wheels, therefore, your front brakes do most of the work when stopping your car or truck. I also know that drums last a lot longer than disc brakes and you don't have to worry about rotor warpage. I believe that it is also cheaper to service drums than discs (not sure about this though). For me though, I love the look of discs behind the rear wheels. From a production standpoint, I would think that discs are cheaper and easier to manufacture (although almost all cars today come equipped with awful rotors that are prone to warping (not just GM!). I always thought drum brakes seemed more complex. However, I'm probably wrong as a lot of "base" cars come with drums in the rear and can be optioned with discs. Are there any direct comparisons in stopping distances of the same car, one equipped with drums and the other discs? I can't see how adding drums would shorten stopping distances....I don't think you would ever see GM putting drums on the Corvette to get a better braking feel, or shorter stopping distances. With that being said, have there been a lot of complaints about the current Silverado regarding the rear brakes? Not in everyday driving, but when hauling heavy loads in the bed or when trailering (what pick-ups are really meant to do)? There has to be a logical explanation for reverting to rear drums....I just hope it does not have to do with saving a couple of bucks on each truck. __________________ 2002 Impala 2008 Equinox

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08-01-2004, 05:41 AM	#2 (permalink)
Erunion 3.8 Liter Supercharged V6 Join Date: Apr 2003 Posts: 511	All 1500s will have rear drums(with possible exception of the SS)? Or will there be any packages with rear disks?

08-01-2004, 06:50 AM	#3 (permalink)
Ultimate 2.2 Liter ECOTEC Join Date: Jan 2003 Posts: 77	wow thats pretty awesome where i can find this info on the SS stopping faster than the new M5?

08-01-2004, 07:37 AM	#5 (permalink)
ByTheLake 6.2 Liter Vortec V8 Join Date: Jun 2004 Location: Traverse City, MI Drives: '04 Corvette, '08 CTS Posts: 2,701	This is just my observation, but given the complexity of a drum brake assembly, it seems to me that it would cost more to assemble and adjust a rear drum brake from a manufacturing perspective than it would for a disk assembly. For manufacturers, rotors and calipers are pretty cheap in volume. Does anybody have data on manufacturing costs of drums vs disks?

08-01-2004, 09:41 AM	#7 (permalink)
LynnJ Walking Join Date: Oct 2003 Posts: 1	Disc brakes aren't necessarily better in every application. A tractor trailer doesn't have the first disc on it. Disc brakes don't have the required surface area to stop something that big of course we are talking at least 60,000 plus pounds. My camaros rear disc pads don't hold up anyway. Whether the truck has disc brakes on the rear or not, if the truck stops quicker and the pedal feel is better then the brake system is better. Although the public won't perceive it that way. Maybe the General should air some commercials testing their new braking system against the competitors if its better. Or maybe they are just trying to add more options to the truck such as disc brakes to help make up some of the lost revenue from the incentives black hole.

08-01-2004, 10:21 AM	#9 (permalink)
ByTheLake 6.2 Liter Vortec V8 Join Date: Jun 2004 Location: Traverse City, MI Drives: '04 Corvette, '08 CTS Posts: 2,701	Now that you mention it, the big rigs use drums, don't they? Maybe there is something 'heavy duty' about them. If the stopping distance is there and the brake feel is good, I'll not lose sleep over this one.

08-01-2004, 12:04 PM	#10 (permalink)
HummerTech 2.5L Iron Duke Join Date: Aug 2004 Posts: 16	Maybe this is their fix for the parking brake problems on the 800 truck?

08-01-2004, 02:07 PM	#13 (permalink)
sheithappens 2.0 Liter Supercharged ECOTEC Join Date: Jun 2003 Posts: 162	http://www.alldata.com/techtips/2004/20040308c.html Jim Grant's Tech Tips '02 Chevy Silverado, Brake Eater Q: My ’02 Chevy Silverado K1500 eats the right rear brakes. The truck has only 43k miles and I’m now on my third set of rear brakes. I had to replace the right rear brake rotor at 18k because I didn’t hear the brake pads grinding and it damaged the rotor. The truck didn’t even make it to 30k miles when the right rear brake was worn out again. Now with 43k I am looking at another brake job on the rear. The front brakes look like new and the left rear was never more then 75% worn, but was replaced each time when the right rear brake was replaced. The mechanic says this is a problem with GM trucks and that it doesn’t matter what brand of brake pads I have put on it will still wear. What’s the deal? Doesn’t GM know how to build trucks that don’t eat up brakes?! A: Oh yes, that infamous right rear brake pad problem. GM has had a problem with the rear brakes on their light duty trucks. There is a fix. The ALLDATA Information System shows GM Technical Service Bulletin # 00-05-23-005B, which to simply describe is a mud flap kit. This kit addresses rapid brake pad wear problem that is found on most GMC and Chevy trucks made from ’99 to ’04. The right rear brake caliper and pads are located in such a manner that road dirt flies right into the brake pads. This steady diet of dirt causes the brakes pads to wear out really fast. The GM mud flap kit is installed to block bombardment of road dirt and debris that is causing the brake pads to wear out so quickly. The GM kit part number is 15765007 and is pretty easy to install. Before your next brake job I would suggest installing the mud flat kit. I think if you check with your dealership they be very agreeable to install the mud flap kit.

08-02-2004, 08:55 AM	#15 (permalink)
ewm2 2.5L Iron Duke Join Date: Jan 2003 Posts: 20	It is amazing that so many people on this board are saying, "GM is decontenting and taking off rear disks on their trucks" rather than saying that if the press is true and the breaks on the trucks have been greatly improved it will be nice. The reason they decontented the rear is so that they could improve the front breaks (that do 75% of the stopping) and therefore improving the performance of the truck.

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