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Old 12-29-2011, 11:13 AM   #1
Rusty Davenport
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Question GM 3500 dually---drum brakes rear---braking improvements

I have a 2000 GM 3500 dually that may have closed out the rear drum brake days of GM. I would like to enhance the stopping power of this truck---has anyone ever actually experimented with this with any success in improved stopping power and what did you do ??? what are the best pads on the front ??? Any comments ???
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Old 12-29-2011, 11:27 AM   #2
Rsmith38
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

I have a 96 dually (rated 10K) with the standard disk/drum setup and tow a 10K trailer with brakes without any problems. I replaced the front pads with HAWK Performance pads when the originals wore out. I also ocasionally tow a 7000 lb trailer without trailer brakes and haven't had a problem.

The duallys had a 12K and 15K rating with different drums, etc but I would expect that changing over would be rather expensive.

What seems to be the problem with stopping?
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Old 12-29-2011, 11:54 AM   #3
Rusty Davenport
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

This is probably a common problem some of us have.....make something better that is already ok.....I drove a newer model ( 2005 ) recently with disk on the rear and it is a world of difference. I would really like to think those dual wheels are digging in, something really seemed to be throwing out the anchor on the disc brake model.
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Old 12-29-2011, 11:24 PM   #4
john kunsak
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

i'd never consider any brand truck exc. GM,but that 88-2000 C-K truck is terrible if you haul a heavy load or trailer. gm should be ashamed of itself for replacing the terrific 74-91 dually crew cab with them! i have a lot of people with the 88-2000 trucks that want better brakes but invariably choke on the price to do it! the 12k gvwr k3500 brakes are exactly the same as the c3500.-13x3.5 front rotor dia.& thick. -same.the increase in gvwr is on paper only! the largest gvwr on that year range truck as a pickup is 10k 2 or 4wd. k3500 4wd c&chassis 12k.c3500 c&c may be 11k,but still all are same brakes. bypassing abs module may help some .also check r whl cyl. diameter. 91& back had 1-3/16 dia. yours may have 1-1/8 or 1-1/16. these were made smaller on some of the mid 80's trucks on up because of rear whl. lockup on slippery.roads & they definitely cut back on braking power.the15k gvwr referred to is only on 91 up hd3500 models . they have rear discs.with a running change in 94 to huge r. discs.the wheels are 10 bolt 19.5 are all that available. the real problem is the small front caliper &pad. you would find much improvement w/ 2001-2006 dually pickup rear axle w/discs. or maybe some a-mkt co.is making a kit heavy enough for this app. now.from personal experience, my own haulers--1979 c30 straight truck w/olenyk 22' enclosed body made from a dually pickup was under-braked . we removed every piece of the suspension down to the frame rails& replaced it w/17k p30mhc pieces with the same rear discs as the hd 3500 . WHAT A N IMPROVEMENT!!!! that being said,the most economic thing to do is sell that truck,&buy a 2001-2007 1st.design w/ 8.1 .a real truck!!!!2x the truck you have now!! e-mail jak502@consolidated.net
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Old 12-30-2011, 09:15 AM   #5
BlueOval Ralph
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

But there is a real problem with the GM trucks with the Hydro-Boost that GM is Not admitting to, be careful the system locks up and the vehicle can not be moved.
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Old 12-30-2011, 09:38 AM   #6
Rusty Davenport
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

Quote:
Originally Posted by john kunsak View Post
i'd never consider any brand truck exc. GM,but that 88-2000 C-K truck is terrible if you haul a heavy load or trailer. gm should be ashamed of itself for replacing the terrific 74-91 dually crew cab with them! i have a lot of people with the 88-2000 trucks that want better brakes but invariably choke on the price to do it! the 12k gvwr k3500 brakes are exactly the same as the c3500.-13x3.5 front rotor dia.& thick. -same.the increase in gvwr is on paper only! the largest gvwr on that year range truck as a pickup is 10k 2 or 4wd. k3500 4wd c&chassis 12k.c3500 c&c may be 11k,but still all are same brakes. bypassing abs module may help some .also check r whl cyl. diameter. 91& back had 1-3/16 dia. yours may have 1-1/8 or 1-1/16. these were made smaller on some of the mid 80's trucks on up because of rear whl. lockup on slippery.roads & they definitely cut back on braking power.the15k gvwr referred to is only on 91 up hd3500 models . they have rear discs.with a running change in 94 to huge r. discs.the wheels are 10 bolt 19.5 are all that available. the real problem is the small front caliper &pad. you would find much improvement w/ 2001-2006 dually pickup rear axle w/discs. or maybe some a-mkt co.is making a kit heavy enough for this app. now.from personal experience, my own haulers--1979 c30 straight truck w/olenyk 22' enclosed body made from a dually pickup was under-braked . we removed every piece of the suspension down to the frame rails& replaced it w/17k p30mhc pieces with the same rear discs as the hd 3500 . WHAT A N IMPROVEMENT!!!! that being said,the most economic thing to do is sell that truck,&buy a 2001-2007 1st.design w/ 8.1 .a real truck!!!!2x the truck you have now!! e-mail jak502@consolidated.net
I have a friend in the repo business---2002 8.1 engines---these trucks roll everyday and have 510,000 miles on them and he has no plan to trade them....THIS IS NO JOKE !!!!!
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Old 12-30-2011, 12:03 PM   #7
Rob Petrie E395
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

We own a bunch of K3500 trucks as well as a few dozen that I see in my shop as customers. The first thing I would do is disable the ABS system and take it out on a wet or gravel road and make sure it will lock up all four tires without the ABS on (at 15-20 MPH it should lock them up with ease). If you dont have the equiptment to do it you can unplug a front wheel speed sensor which will set a code and disable the ABS. When you plug it back in and drive it a few miles it will reset itself and reactivate the ABS so dont worry about not having a scan tool to reset it when you are done. You need to have the ABS disabled or you cant tell if its not locking them up because the abs is kicking in or because you are not making the pressure needed to lock them. Anyways if it is only locking one or the other rear wheel 9 times out of 10 you have a stuck wheel cyl (alot of times even though it only has brakes working on one rear wheel it wont pull it just does not seem to want to stop when loaded). I see this mostly on trucks that rarely pull a trailer and were bought before gas prices got high because it was "cool" to have a crew cab dually for a daily driver. If it does not seem like it wants to lock them at all or has weak braking capibilities 9 times out of 10 they have a bad hydroboost. You still need to check it over good to make sure there is not another problem but I have seen more weak hydroboost units than anything else where weak breaking is concerned. The biggest problem I see on these trucks are the front rotors warp if you try and pull heavy trailers with no trailer brakes (I see this on farm trucks all the time). My personal truck (98 k3500) pulled a 44' Haulmark untill last year and I never had a problem stopping. If you want to make sure its the hydro before spending the money you can get a gauge from Strange Engeneering for about 40 bucks that screws into where the bleeder screw goes to check pressures instead of the high dollar Kent Moore stuff.
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Old 12-30-2011, 01:53 PM   #8
BlueOval Ralph
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Default Re: GM 3500 dually---drum brakes rear---braking improvements

There also was problem with rear axle seal on the floaters that cause a rear lock up problem only took 3 trips to the dealer to find it on our truck!
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