Heavy Duty rear drum brakes for 1/2 tons... FYI - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Tx Firefighter · 01-28-2006, 08:27 PM

I learned a little nugget a few weeks ago. Some 1/2 tons had much larger rear brakes than most. This isn't like discovering Plutonium or anything, but it's not common knowledge.

I swapped rear ends under my beater, and took pictures of the differences. Both were 5 lug 12 bolt normal rearends.

I don't know what option code to look for, but I was told this is a 72 Suburban rearend.

It would be a good way to get better rear brakes.

The overall width is identical, so it doesn't affect track width or wheel and tire fitment. The extra depth is in the backing plates. They are dished on the wider setup.

**lolife99** · 01-28-2006, 08:54 PM

Thanks for the HOT tip. You learn something every day. Maybe this is the heavy duty brakes that ECE sells.

junkyardjohn · 01-28-2006, 09:10 PM

I Took The Complete Rear Brake & Drum Assy. Including The Backing Plates Off Of A 75 C-10 , That I Was Pulling The Front Crossmember Assy. Out Of To Put Under A 69. The Shoes Were About 2 5/8" Wide Instead Of 2".I Put Them On My 69 & It Made A Noticable Difference.

John

72swbcamo · 01-28-2006, 10:29 PM

I bought the heavy duty brake upgrade from ECE. I thought it was a little pricey but you get everything brand new. It would be a lot more work to find a rear with the bigger brakes and have to disassemble them, clean and replace all the worn parts. So it may be woth it. Those larger finned drums don't come cheap. I'm glad to hear that there was a noticeable difference in the braking performance. I guess the it will all be worth it.

matthufham · 01-28-2006, 10:39 PM

interesting, makes me want to find out what i have in my 72.

problem is, i can't get my drums off! they seem to be stuck on. i checked the parking brake, blew some dirt out of the inspection holes, hit them from all directions with a ball peen hammer, still don't want to come off. is there a trick here? maybe someone could just measure the drums so i don't have to measure my pads.

Tx Firefighter · 01-28-2006, 10:49 PM

Hit the drums real hard perpendicular with their face. Hit them on the smooth part right behind where the wheel mounts. I used to get some real stuck drums on the mail trucks. We always used a 3lb mini sledge. You won't hurt the drums as long as you don't hit them real hard out on the lip.

matthufham · 01-28-2006, 10:57 PM

i'll try tomorrow definately. it wiggles but doesn't come off so i thought something might of been holding it back.

Longhorn Man · 01-28-2006, 11:01 PM

If the drums wiggle on the studs, then you probably need to back the shoes off.

CHYNSPR · 01-28-2006, 11:50 PM

Junkyardjohn, are you saying that the newer C-10 big brakes will bolt up to a '69 rear axle, or a '72 for that matter? ( I have both ).

**PICKMUP** · 01-29-2006, 12:50 AM

I think all 73+ PUs use the larger rear brakes. You just take the complete backing plate with all shoes, parts & drums and bolt it on your earlier model. It is a lot cheaper than rear disc systems and helps a bunch.

Same applies to 4x4 6lug trucks. We have been upgrading 1/2T 4x4 with this setup for a long time.

The only hassle is if you are junk yarding, you will have to pull the axles to get the assys off.

krue · 01-29-2006, 12:54 AM

That's good to know.

junkyardjohn · 01-29-2006, 01:28 AM

Quote:

Originally Posted by CHYNSPR

Junkyardjohn, are you saying that the newer C-10 big brakes will bolt up to a '69 rear axle, or a '72 for that matter? ( I have both ).

YUP .. BUT YOU HAVE TO TAKE EVERYTHING TO & INCLUDING THE BACKING PLATE. A PRETTY GOOD UPGRADE FOR NOT ALOT OF $$$

JOHN

cheyenne10 · 01-29-2006, 01:56 AM

Any reason the 6 lug 4x4 stuff wouldn't work on 6 lug 2 wheeler? Are these identifiable from the outside? (width of drum in inches?)

69TowRig · 01-29-2006, 02:16 AM

Hmm, maybe I'll do this instead of rear discs...

jimfulco · 01-31-2006, 11:59 PM

Not all of the later pickups use the wider brakes. I just junked an '84 that had the thin ones.

matthufham · 02-01-2006, 12:27 AM

my 72 c10 has 2 inchers, i finally got the drums off. thanks longhorn, loosened the star wheel all the way and it finally came off. didnt want to o back on but i got it done eventually.

roger0080 · 02-01-2006, 12:52 AM

I belive those are the 11-5/32" drums, GM #14070351.

I have those on my 77 C10.

Best I can tell is that it is part of the RPO F44 HEAVY DUTY CHASSIS EQUIPMENT or else (?) comes with the HE4 REAR AXLE -3.40 RATIO option? from my SPID sticker.

Steve Vos · 06-04-2009, 08:20 PM

I have a 69 gmc with 72 front discs and the 11 5/32 rear HD drums on 5 bolt axles. The rear brakes came off a 73+ axle. They all bolted up to the rear housing great which is off a 70 and converted to 5 bolt. The problem I have is my pedal effort is too high and the stroke is too short compared to my 86 Silverado. I have good vacuum from the 396 engine. I used a 72 master and booster and a proportioning valve of unknown origin. I looks like the valve for an 81-87 Chevy listed on the inlinetube.com web site so I think that may be what it is. I also see these brakes listed in the 73-87 LMC catalog. In there they list different masters, proportioning valves, and boosters based on the larger drums. I am wondering if my setup is not correct. Does anyone out there know about this and what would work? Do I need to match the parts to these particular rear brakes? If I have to change boosters I would like to find a smaller dia to get more valve cover clearance. Any recommendations there?

Thanks in advance for any help.

**Hart_Rod** · 06-04-2009, 08:33 PM

I got mine off of a 71 Big block camper special. I think it was on the option code but not sure.

ERASER5 · 06-04-2009, 11:41 PM

I wish I had found this thread a couple of months ago. Before I did all the research to find exactly what this thread is talking about. The only thing I could not find info on was the backing plate.

All was for naught. They don't make 6 lug big brake drums.

At least I could not find them.

ERASER5 · 06-05-2009, 12:01 AM

I reread pickemup's post. I did not think to look at 73+ 4X4 stuff. (slaps head)

72BlckButy · 06-05-2009, 07:43 AM

Quote:

Originally Posted by lolife99

Thanks for the HOT tip. You learn something every day. Maybe this is the heavy duty brakes that ECE sells.

That's the same thing I thought after reading his post...

mbgmike · 06-05-2009, 07:13 PM

The 11" x2" were used from 1963 to 1975.The larger 2.3/4" x11.5/32" were also used in the early 60's up to 1975. Just about any engine combination from 230 up to 454 and any 1/2 ton truck,burb or van.The same parts on certain years are also found some Dodge trucks and also some Jeeps. I don't have a clue why their are some many combos.

mbgmike · 06-05-2009, 07:26 PM

Some 1972 trucks did not have them and some did. seems like more 70 to 71 models had them than others. Its really confusing to see all the combinations. Thats why its so hard for parts guys to get the correct ones. I think all the 305 V6 GMC trucks had them but not entirely sure.

ECE just sell the larger brakes is correct like most all parts companies. Nothing special

mbgmike · 06-05-2009, 07:43 PM

Quote:

Originally Posted by ERASER5

I reread pickemup's post. I did not think to look at 73+ 4X4 stuff. (slaps head)

pickmeups correct they used them even on the 6 cylinder versions

01-28-2006, 08:54 PM	#2
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,691	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Thanks for the HOT tip. You learn something every day. Maybe this is the heavy duty brakes that ECE sells. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

01-28-2006, 09:10 PM	#3
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,427	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I Took The Complete Rear Brake & Drum Assy. Including The Backing Plates Off Of A 75 C-10 , That I Was Pulling The Front Crossmember Assy. Out Of To Put Under A 69. The Shoes Were About 2 5/8" Wide Instead Of 2".I Put Them On My 69 & It Made A Noticable Difference. John __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST Last edited by junkyardjohn; 01-28-2006 at 09:19 PM.

01-28-2006, 10:29 PM	#4
72swbcamo Active Member Join Date: Dec 2003 Location: Waterbury, CT Posts: 591	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I bought the heavy duty brake upgrade from ECE. I thought it was a little pricey but you get everything brand new. It would be a lot more work to find a rear with the bigger brakes and have to disassemble them, clean and replace all the worn parts. So it may be woth it. Those larger finned drums don't come cheap. I'm glad to hear that there was a noticeable difference in the braking performance. I guess the it will all be worth it.

01-28-2006, 10:39 PM	#5
matthufham Registered User Join Date: Feb 2005 Location: Carl Junction, Missouri Posts: 2,061	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI interesting, makes me want to find out what i have in my 72. problem is, i can't get my drums off! they seem to be stuck on. i checked the parking brake, blew some dirt out of the inspection holes, hit them from all directions with a ball peen hammer, still don't want to come off. is there a trick here? maybe someone could just measure the drums so i don't have to measure my pads.

01-28-2006, 10:49 PM	#6
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Hit the drums real hard perpendicular with their face. Hit them on the smooth part right behind where the wheel mounts. I used to get some real stuck drums on the mail trucks. We always used a 3lb mini sledge. You won't hurt the drums as long as you don't hit them real hard out on the lip. __________________ I'm on the Instagram- @Gearhead_Kevin

01-28-2006, 08:27 PM	#1
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Heavy Duty rear drum brakes for 1/2 tons... FYI I learned a little nugget a few weeks ago. Some 1/2 tons had much larger rear brakes than most. This isn't like discovering Plutonium or anything, but it's not common knowledge. I swapped rear ends under my beater, and took pictures of the differences. Both were 5 lug 12 bolt normal rearends. I don't know what option code to look for, but I was told this is a 72 Suburban rearend. It would be a good way to get better rear brakes. The overall width is identical, so it doesn't affect track width or wheel and tire fitment. The extra depth is in the backing plates. They are dished on the wider setup. Attached Images __________________ I'm on the Instagram- @Gearhead_Kevin Last edited by Tx Firefighter; 01-28-2006 at 08:28 PM.

01-28-2006, 10:57 PM	#7
matthufham Registered User Join Date: Feb 2005 Location: Carl Junction, Missouri Posts: 2,061	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI i'll try tomorrow definately. it wiggles but doesn't come off so i thought something might of been holding it back.

01-28-2006, 11:01 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI If the drums wiggle on the studs, then you probably need to back the shoes off.

01-28-2006, 11:50 PM	#9
CHYNSPR Registered User Join Date: Jan 2006 Location: Grande Prairie, Alberta Posts: 202	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Junkyardjohn, are you saying that the newer C-10 big brakes will bolt up to a '69 rear axle, or a '72 for that matter? ( I have both ).

01-29-2006, 12:50 AM	#10
PICKMUP "Trucks with Class" Join Date: Jul 2000 Location: OLYMPIA, WA, USA Posts: 8,125	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I think all 73+ PUs use the larger rear brakes. You just take the complete backing plate with all shoes, parts & drums and bolt it on your earlier model. It is a lot cheaper than rear disc systems and helps a bunch. Same applies to 4x4 6lug trucks. We have been upgrading 1/2T 4x4 with this setup for a long time. The only hassle is if you are junk yarding, you will have to pull the axles to get the assys off.

01-29-2006, 12:54 AM	#11
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI That's good to know. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

01-29-2006, 01:56 AM	#13
cheyenne10 Senior Member Join Date: Apr 2000 Location: Oregon Posts: 2,512	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Any reason the 6 lug 4x4 stuff wouldn't work on 6 lug 2 wheeler? Are these identifiable from the outside? (width of drum in inches?) __________________ Bob

01-29-2006, 02:16 AM	#14
69TowRig Senior Member Join Date: Jan 2005 Location: Raleigh, NC Posts: 894	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Hmm, maybe I'll do this instead of rear discs... __________________ -Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals...

01-31-2006, 11:59 PM	#15
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Not all of the later pickups use the wider brakes. I just junked an '84 that had the thin ones.

02-01-2006, 12:27 AM	#16
matthufham Registered User Join Date: Feb 2005 Location: Carl Junction, Missouri Posts: 2,061	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI my 72 c10 has 2 inchers, i finally got the drums off. thanks longhorn, loosened the star wheel all the way and it finally came off. didnt want to o back on but i got it done eventually.



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02-01-2006, 12:52 AM	#17
roger0080 Registered User Join Date: Nov 2000 Location: Carver County, Minnesota, USA Posts: 626	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I belive those are the 11-5/32" drums, GM #14070351. I have those on my 77 C10. Best I can tell is that it is part of the RPO F44 HEAVY DUTY CHASSIS EQUIPMENT or else (?) comes with the HE4 REAR AXLE -3.40 RATIO option? from my SPID sticker. __________________ 72 Chev C-10 90% restored (former AZ truck) ... 71 Chev K-20 Cheyenne my vacation crusier... 72 Chev C-10 Now retired and striped after many faithful miles... 72 GMC 1500 Retired to the junk yard after bought new in '71...

06-04-2009, 08:20 PM	#18
Steve Vos Registered User Join Date: Jan 2006 Location: Jackson, Tennessee Posts: 5	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I have a 69 gmc with 72 front discs and the 11 5/32 rear HD drums on 5 bolt axles. The rear brakes came off a 73+ axle. They all bolted up to the rear housing great which is off a 70 and converted to 5 bolt. The problem I have is my pedal effort is too high and the stroke is too short compared to my 86 Silverado. I have good vacuum from the 396 engine. I used a 72 master and booster and a proportioning valve of unknown origin. I looks like the valve for an 81-87 Chevy listed on the inlinetube.com web site so I think that may be what it is. I also see these brakes listed in the 73-87 LMC catalog. In there they list different masters, proportioning valves, and boosters based on the larger drums. I am wondering if my setup is not correct. Does anyone out there know about this and what would work? Do I need to match the parts to these particular rear brakes? If I have to change boosters I would like to find a smaller dia to get more valve cover clearance. Any recommendations there? Thanks in advance for any help. __________________ '69 GMC 396/TH400 SWB '86 Silverado 350/350 LWB

06-04-2009, 08:33 PM	#19
Hart_Rod ************* Join Date: Apr 2005 Location: Pensacola, FL Posts: 17,837	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I got mine off of a 71 Big block camper special. I think it was on the option code but not sure. __________________ Rob - https://www.instagram.com/hart_rod_c10 As Iron Sharpens Iron, So One Man Sharpens Another. Proverbs 27:17 FOR SALE: DBW pedal bracket - http://67-72chevytrucks.com/vboard/s...d.php?t=651123 FOR SALE: Hood Brackets http://67-72chevytrucks.com/vboard/s...d.php?t=679945 1987 Silverado SWB - 34.5K original miles http://67-72chevytrucks.com/vboard/s...d.php?t=801834 1969 SuperBurb - http://67-72chevytrucks.com/vboard/s...d.php?t=200387 1968 Farm truck - http://67-72chevytrucks.com/vboard/s...d.php?t=358692 1968 SWB - http://67-72chevytrucks.com/vboard/s...d.php?t=551258 1948 Chevy - http://67-72chevytrucks.com/vboard/s...=122164&page=3

06-04-2009, 11:41 PM	#20
ERASER5 Registered User Join Date: Jun 2006 Location: Indiana Posts: 4,859	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I wish I had found this thread a couple of months ago. Before I did all the research to find exactly what this thread is talking about. The only thing I could not find info on was the backing plate. All was for naught. They don't make 6 lug big brake drums. At least I could not find them. __________________ '70 GMC C1500 LWB Power disc brakes. WooHoo! Posi 6 Lug Dana 60

06-05-2009, 12:01 AM	#21
ERASER5 Registered User Join Date: Jun 2006 Location: Indiana Posts: 4,859	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI I reread pickemup's post. I did not think to look at 73+ 4X4 stuff. (slaps head) __________________ '70 GMC C1500 LWB Power disc brakes. WooHoo! Posi 6 Lug Dana 60

06-05-2009, 07:13 PM	#23
mbgmike Registered User Join Date: Aug 2005 Location: Pasadena,Tx /Pto Pta DR Posts: 5,415	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI The 11" x2" were used from 1963 to 1975.The larger 2.3/4" x11.5/32" were also used in the early 60's up to 1975. Just about any engine combination from 230 up to 454 and any 1/2 ton truck,burb or van.The same parts on certain years are also found some Dodge trucks and also some Jeeps. I don't have a clue why their are some many combos.

06-05-2009, 07:26 PM	#24
mbgmike Registered User Join Date: Aug 2005 Location: Pasadena,Tx /Pto Pta DR Posts: 5,415	Re: Heavy Duty rear drum brakes for 1/2 tons... FYI Some 1972 trucks did not have them and some did. seems like more 70 to 71 models had them than others. Its really confusing to see all the combinations. Thats why its so hard for parts guys to get the correct ones. I think all the 305 V6 GMC trucks had them but not entirely sure. ECE just sell the larger brakes is correct like most all parts companies. Nothing special

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