<H2 style="MARGIN: 0in 0in 0pt">Bosch, GM Bolster Truck Brakes</H2>
Joint project reduces pedal pressure, distance for stopping of 2005 Sierra and Chevrolet Silverado
<H2 style="MARGIN: 0in 0in 0pt">The Detroit News</H2>
By Ed Garsten
May 25, 2004

MILFORD — Hoping to overcome negative consumer feedback and improve a key product amid stiff new competition, General Motors Corp. (javascript companybox('GM')) and brake supplier Robert Bosch AG have teamed up to develop a new braking system for the 2005 GMC Sierra and Chevrolet Silverado pickup trucks.

The new brakes will allow drivers to stop or slow more quickly while applying less pressure on the pedal.

The Silverado and Sierra are two of GM’s best-selling and profitable vehicles but are squaring off in the U.S. marketplace with the all-new Ford F-150 and Nissan Titan, as well as the Dodge Ram.

With the new brakes, the amount of time needed to stop has been reduced by two seconds and stopping distance has been cut by 85 feet, using just the front brakes.

In recent J.D. Power and Associates quality studies, customers complained that it took too much effort to depress the brake pedal, that the pedals felt mushy or soft and that the brakes just didn’t have enough stopping power.

“People said when they first touched the brakes they felt nothing,” said Ken Hamann, director of brake systems for GM.
<SPAN s

Light Duty ONLY!

Stops quicker...GOOD


Rear drum brakes...BAD

Rear drum brakes? On 1500's only right?

Yeah, I would like to know what they are putting the rear drums on as well. I hate rear drum brakes and if they are doing this on all the Silverado's and Sierra's that is bad IMO. Better braking is good, but I don't like drum brakes. It is just GM trying to save money again, I think...

I have rear drums for my 96 Z71 and I am looking forward to having a newer truck with disc brakes instead of drum.

The HD's are a different breed. The article made a mistake of omission. They should have specified non HD trucks.

Don't worry boys, the rear rotors ain't going nowhere.

The brakes on my 2001 GMC HD were excellent and lasted forever. Feel was good.

But when I drive my 94 full size Blazer, I can't believe GM got away for so long with that sponge pedal. Edited by: hoot

"The Silverado had 10.5 problems per 100 models, and the Sierra had 12.6 problems per 100."


That settles it, the Chevy really is better than the GMC... http://www.dieselplace.com/forum/smileys/Clown.gif

"The Silverado had 10.5 problems per 100 models, and the Sierra had 12.6 problems per 100."


That settles it, the Chevy really is better than the GMC... http://www.dieselplace.com/forum/smileys/Clown.gif





Always a matter of interpretation isn't it?


I see that as meaning GMC owners are more discerning...http://www.dieselplace.com/forum/smileys/Clown.gif

http://www.dieselplace.com/forum/smileys/HiHi.gif Excellent point!


It also explains how Ford and Dodge had even fewer defects. http://www.dieselplace.com/forum/smileys/Clap.gif

Whew!!!!, I was going to say...DRUM BRAKES...OH NO, NOT AGAIN!!!!


My Dually brakes are the best of any truck I have ever owned. No pulling, very responsive and zero fad when I have submerged the truck in water up to the brakes. Plus the ease of replacement ....


Jeff

Whew!!!!, I was going to say...DRUM BRAKES...OH NO, NOT AGAIN!!!!


My Dually brakes are the best of any truck I have ever owned. No pulling, very responsive and zero fad when I have submerged the truck in water up to the brakes. Plus the ease of replacement ....


Jeff




Have you replaced your rears yet?

Goes to show you that those that choose to drive junk, just don't complain.


Us GMC folks expect the very best, and get it. Take that you "Anrgy Chinaman" drivers!http://www.dieselplace.com/forum/smileys/Evil Smile.gif


With tongue firmly planted in cheek....

The discs on the 1500's are the worst brakes ever made if you get the truck dirty. As a forester, I had two company 1500's, that were immersed regularly in log yard mud, and constantly travelling dirt roads. I finally got to the point of swapping pads on the passenger side every other oil change (6000 miles), otherwise they would grind down to the rotors in less than 10,000. This was totally unnacceptable and I would have killed to have rear drums. However, the 2500HD's we had, never seemed to suffer from these problems. Weird, but true. I kept telling them to get me an HD, but no avail.

The man that owned my trcuk before, had to have his rears replace at just shy of 20K. I cant remember exactly what he said, but it was that something (sorry dont remember, not brake savy) had almost complelty wore through the rotor?? One side was a bit worse than the other. Had to replace pads and rotors. He said he encountered the same problem w/his previous 1/2toners..
He mentioned to me to keep an eye on them after like 13-15K, and to try and get it back in before bumper-bumper expires...Said this was a major problem w/gm. Hes retired from Chevy, and knows his sh!t, so http://www.dieselplace.com/forum/smileys/Confused.gif....

"- - - The improvements to the brakes in the Silverado and Sierra include a new master cylinder that helps reduce pedal travel, along with larger front rotors and larger rear brake drums, Woychowski said."


That "- - and larger rear brake drums, - - - " told me it pertained to something not mine ~

Regarding the premature wearing of the back brakes, GM has a bulletin or tech note out with instructions for installing mud flaps in the front of the wheel wells for vehicles that are subjected to a lot of mud. These are supposed to fix the (admitted) problem. The logic of this is not apparent to me and if it makes sense to someone else I'd like to hear it.

Have your dealer look it up. If you can't find it I'll try to find it again.

Tried the mudflaps, helped very little. Tried washing them thoroughly every week. Helped very little. My F250 had rear discs that also wore out a little faster than they should have. I think disc brakes belong on cars. But the HD ones seem fine. Of course, my own HD is mostly used for highway towing.

I had rear drum brakes on my 2000 OBS 2500, CCSB 454. Brakes were very mushy. The only thing was at about 35,000 miles I was geting the front breaks serviced, and the service guy checked the rear drums and said they were still good, had about 50% werar on them, but to replace them they would have to drop the whole rear axle to do it http://www.dieselplace.com/forum/smileys/Confused.gif

I only see the last line of the article states larger rear drums, could it be a mistake? The link does not work for me.


How can they have larger rear drums if they didn't have drums to start?

Ive got those mudflaps in the front of the rear wheel....the one side has been blowing back into the tire, and is wearing away fast...needs sometype of brace to keep it from floating...i still dont see howd they stop anything??

The theory was that dirt was the problem. It would cause the calipers to bind up and one pad would wear out, while the other was still fine. The mudflap was to try and keep the brakes cleaner. Like I said, I doubt it did anything for the ones I had. The HD's don't seem to suffer from the problem like the 1500's do. I work around a lot of loggers who have 60k miles plus on the original rear pads on the HD's.

I read the article and took it as a typo myself,the old drum brakes were so lousy I can't see them taking a step backwords!!We will just have to see but i think the disks will stay my self.

Call me blind, but I have seen very little to no discussion on this forum on poor brake quality. Myself, I find the brakes on my HD to be about the best I have had on any truck. Admit I primarily use on highway pulling a 5er, but even with the 5er, I have had no complaints on feel or performance.

They are referring to only the 1500 series trucks -- the HD's have excellent brakes.


The brakes on the prior generation of 2500 &amp; 3500 trucks were absolutely terrible. GM responded by over-engineering the brakes on the HD's.

At 60,000 miles on my HD I just had all 4 rotors cut due to warpage. The tech showed me the calpers while the truck was on the lift and none of the pads front or rear showed excessive wear. (most maybe 1/3 worn) Although the truck has always stopped great, I have complained to the dealer about pedal feel.


I found the pedal feel on my 88 ext cab w 6.2 diesel a lot better , although stopping times were definately longer.


The tech did say they have had lots of problems with pass side rears wearing out (both pads and rotors) but the mud flap fix has seemed to correct the problem for the local customers here.He did not specify HD or LD when we were talking.


Edited by: ctgmcduramax

The tech did say they have had lots of problems with pass side rears wearing out (both pads and rotors) but the mud flap fix has seemed to correct the problem for the local customers here.He did not specify HD or LD when we were talking.


That`s not a fix, that's a bandaidhttp://www.dieselplace.com/forum/smileys/Cry.gif Buy a $45,000 (Sticker price) truck and take it home and hillbilly and red neck it to no endhttp://www.dieselplace.com/forum/smileys/Big Smile.gif I don't think so!http://www.dieselplace.com/forum/smileys/Confused.gif

Talked with a Chev salesman today and he said all trucks in the 2006 model year will be back to rear drums again. Go figurehttp://www.dieselplace.com/forum/smileys/Ermm.gif

The tech did say they have had lots of problems with pass side rears wearing out (both pads and rotors) but the mud flap fix has seemed to correct the problem for the local customers here.He did not specify HD or LD when we were talking.





That`s not a fix, that's a bandaidhttp://www.dieselplace.com/forum/smileys/Cry.gif Buy a $45,000 (Sticker price) truck and take it home and hillbilly and red neck it to no endhttp://www.dieselplace.com/forum/smileys/Big Smile.gif I don't think so!http://www.dieselplace.com/forum/smileys/Confused.gif





You got that right!! My 95 K2500 had the worst brakes of any vehicle I've ever owned!! It went back to the dealer 6 times for brakes and 3 times for leaking axle seals before they finally put in a new rear axle.


ROB

My understanding is 2006 BASE 1500 trucks will have rear DRUM brakes. We will see in a few months http://www.dieselplace.com/forum/smileys/Big Smile.gif

The Quadrasteer trucks will keep thier disc brakes in the rear.

From GMInsidenews.com

Chevrolet Silverado/ HD
New for 2005

-Hybrid version of half-ton 1500 Extended Cab model
-Higher output (310 hp/231 kw) Vortec 5300 5.3L V-8 (available on 4WD Extended Cab w/standard box)
-Power sunroof package (available late 2004 on Extended and Crew Cab models with Universal Transmitter and overhead console)
-Front disc/rear drum anti-lock brakes standard on all models except with Quadrasteer
-(QPR) P245/70R17-108S all-season blackwall tires standard on 2WD models
-(QPO) P245/70R17-108S all-season, white-outlined letter tires available on 2WD models
-(QVL) P265/70R17, all-season, blackwall tires standard on 4WD Regular/Extended Cab models
-(QVM) P265/70R17, all-season, white outlined-letter tires available on 4WD Regular/Extended Cab models
-Six -lug painted 17-inch x 7-inch steel wheels standard on Work Truck Models
-Six-lug chrome-styled steel 17-inch x 7.5-inch (except 2WD Extended Cab and 2WD/4WD Crew Cab models)
-3.23 rear axle ratio standard on 2WD models
-145-amp alternator standard
-Snow Plow prep package includes 160-amp alternator
-New hood and grille design for Heavy Duty· models·
-New exterior colors: Dark Blue Metallic (all except Silverado SS), Silver Birch Metallic (Silverado SS)
-OnStar driver safety and security system, featuring Gen 6 hardware with analog/digital coverage and upgraded hands-free capabilities. Standard on light-duty LT, available on LS; standard on heavy-duty Silverado LT Extended Cab and Crew Cab, available on 2500HD and 3500 models.
----------------------------------------

I would think this would add more manufacturing and service cost to have different brake types.

Broker


I haven't seen your comments about the brakes on the 3500. How about it,How far do they go.


Genohttp://www.dieselplace.com/forum/smileys/Hug.gif

<H2>This is from the 2005 product information guide on media.gm.com. I pulled this from the GMC truck specs, but it applies to the Chevy trucks, too.</H2>
<H2>SPECIFICATIONS – SIERRA</H2>
<H2>


Brakes
<TABLE cellSpacing=0 cellPadding=0 border=1>
<T>
<TR>
<TD vAlign=top colSpan=2 76>


Type:</TD>
<TD vAlign=top colSpan=2 88></TD></TR>
<TR>
<TD vAlign=top colSpan=2 76>


Most models:</TD>
<TD vAlign=top colSpan=2 88>


vacuum boost power, front disc, rear-drum 4-wheel ABS, DRP</TD></TR>
<TR>
<TD vAlign=top colSpan=2 76>


1500HD, 1500 with Quadrasteer:</TD>
<TD vAlign=top colSpan=2 88>


vacuum boost power, 4-wheel disc, 4-wheel ABS, DRP</TD></TR>
<TR>
<TD vAlign=top 74></TD>
<TD vAlign=top width=146 colSpan=2>


Front</TD>
<TD vAlign=top width=144>


Rear</TD></TR>
<TR>
<TD vAlign=top 74>


Rotor or drum diameter x thickness (in / mm): </TD>
<TD vAlign=top width=146 colSpan=2></TD>
<TD vAlign=top width=144></TD></TR>
<TR>
<TD vAlign=top 74>


1500 up to 7000 GVWR: </TD>
<TD vAlign=top width=146 colSpan=2>


13 x 1.18 / 330 x 30 </TD>
<TD vAlign=top width=144>


11.65 x 2.36 / 295 x 60</TD></TR>
<TR>
<TD vAlign=top 74>


1500 with Quadrasteer: </TD>
<TD vAlign=top width=146 colSpan=2>


12.01 x 1.14 / 305 x 29 </TD>
<TD vAlign=top width=144>


13 x 1.18 / 330 x 30</TD></TR>
<TR>
<TD vAlign=top 74>


Axle swept area (sq in / sq cm): </TD>
<TD vAlign=top width=146 colSpan=2></TD>
<TD vAlign=top width=144></TD></TR>
<TR>
<TD vAlign=top 74>


1500 up to 7000 GVWR: </TD>
<TD vAlign=top width=146 colSpan=2>


256.7 / 1656 </TD>
<TD vAlign=top width=144>


174.5 / 1126</TD></TR>
<TR>
<TD vAlign=top 74>


1500 with Quadrasteer:</TD>
<TD vAlign=top width=146 colSpan=2>


213.6 / 1378</TD>
<TD vAlign=top width=144>


223.7 / 1443</TD></TR>
<TR height=0>
<TD 74></TD>
<TD></TD>
<TD width=144></TD>
<TD width=144></TD></TR></T></TABLE><A name=ldspecs></A></H2>
<H2>SPECIFICATIONS – SIERRA 2500HD, 3500<A name=hdspecs></A></H2>
<H2>Brakes</H2>
<TABLE cellSpacing=0 cellPadding=0 border=1>
<T>
<TR>
<TD vAlign=top 41>


Type: </TD>
<TD vAlign=top width=330>


power, Hydroboost brake-apply system, four-wheel disc, four-wheel ABS</TD></TR>
<TR>
<TD vAlign=top 41>


Rotor diameter x thickness (in / mm):</TD>
<TD vAlign=top width=330>


front: 12.8 x 1.5 / 325 x 38; rear: 12.8 x 1.2 / 325 x 30</TD></TR>
<TR>
<TD vAlign=top 41>


Total swept area (sq in / sq cm):</TD>
<TD vAlign=top width=330>


front: 245.5 x 1583.8; rear: 235.1 / 1516.6</TD></TR></T></TABLE>





There were 2 different sections on the website for the Sierra truck specifications. The first one was from the Specification - LD page, and the 2nd one is from Specification - HD page. Rear drum brakes will only apply to the light duty trucks (at least for 2005).