Eaton HO72 Brake Drums Q? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Preal · 03-19-2018, 06:59 PM

Gents, I’ve read until I’m blue in the face regarding DRW Eaton HO72 drums. I know they don’t reproduce the 13x2.5 drums used on the DRW’s but I have a thought. Only thinking this much because I’m having trouble finding 14bff complete DRW Brake setups locally.

The SRW 14bff used in the 73 up c30 and c20 uses a 13x2.5 Brake as well. I’m sure there are some differences in the backing plates but why wouldn’t a 13x2.5 14bff drum fit an HO72 without issue? I know the entire brake systems will mount between the two axles, how different can the backing plates really be.....

Has anyone tried this type of setup.
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**special-K** · 03-20-2018, 07:52 AM

I think it may be the overall shape and dimensions that vary. Meaning where that 2.5" lays in relation to the axle flange... depth of drum body. That is the only thing I can think of that would matter.

Bigdav160 · 03-20-2018, 08:44 AM

There might be differences in the bearings. Just pondering since IDK

Preal · 03-21-2018, 03:30 PM

Quote:

Originally Posted by special-K

I think it may be the overall shape and dimensions that vary. Meaning where that 2.5" lays in relation to the axle flange... depth of drum body. That is the only thing I can think of that would matter.

I know the dimensions will be slightly different but I'm thinking they may be just lose enough. People use the brakes from the backing plate out from the 14bff and they work great. I know the hub flange on the 14bff drums are thicker but longer studs will fix that.

Looks like I'm just going to have to pull off a drum and run to the parts store to see the differences.

**special-K** · 03-21-2018, 05:47 PM

I believe I was the one who brought that knowledge to this site about the 14-bolt brakes complete swap. I figured if the disc brake kits can work on an HO52/72 why not drum brakes from backing plate out, and it worked. I never tried what you are considering, but maybe it could work. Just have to get your hands on a 14-bolt FF drum and try it. I'm just wondering why people swap it all and not just the drums. Maybe it's as simple as no one has tried because the word out there is do the whole deal.

The reason I tried the 14-bolt drum brake swap was I had a guy with a '72 rollback that was given my number to see if I had the drums. I didn't and he needed to get brakes on that thing like yesterday so he could get it through inspection to meet the requirements for number of trucks for a big towing contract and the brake drums flunked. We didn't have time to "try" things and I was 99.9% sure this complete swap would work... and it did. He had it through inspection in less than 24 hours from his call to me.

Preal · 11-25-2018, 06:52 PM

Bringing this back from the dead.

Had to pull the engine to fix some leaks and soon the brakes will be next on my list.

Do I need to get 14 bolt dually rear brakes or will the 13x2.5 wok as will on my 71 dually?

**StingRay** · 11-26-2018, 11:08 AM

Last time I looked Centric was making drums for the the HO72. Not cheap though.

**Wrenchbender Ret** · 11-26-2018, 11:23 AM

I used to put the later drums on the older model hubs. I had a machine shop drill out the stud holes & used the later model studs & nuts.
George

Preal · 11-26-2018, 12:23 PM

Quote:

Originally Posted by StingRay

Last time I looked Centric was making drums for the the HO72. Not cheap though.

They show up for 67-70 but not 71-72. I would imagine the only difference is the stud diameter.

Has anyone actually purchased the centric drums?

Preal · 11-26-2018, 01:27 PM

Quote:

Originally Posted by Wrenchbender Ret

I used to put the later drums on the older model hubs. I had a machine shop drill out the stud holes & used the later model studs & nuts.
George

Did you just use the drums or did you use the backing plates and all?

**Wrenchbender Ret** · 11-26-2018, 10:55 PM

Just the drums & studs. Everything else was the old original parts.

Preal · 11-26-2018, 10:58 PM

Quote:

Originally Posted by Wrenchbender Ret

Just the drums & studs. Everything else was the old original parts.

Was it single rear wheel or dually? My 71 dually has 13x2.5” brakes the 14 bolt 13x3.5” brakes. Wouldnt that hit the backing plate?

Preal · 12-13-2018, 11:28 PM

Problem solved! Ordered the centric rear dually drums for a 67-70 c30 and drilled out the stud holes to accommodate a 9/16 stud. Was super easy. I used the old drum as a template to ensure the drill bit was centered and the angle on the bit did the rest. Glad to not have to upgrade to 14bff brakes!

JerryIndy2112 · 11-10-2019, 01:42 PM

I found this thread in a search. I am in the situation of having bad drums on my C3500, 1971. It has single rear wheels. I also found these drums are not made anymore. I have some questions about doing this. How do I separate the drums from the bearing hub? Will I need all new lugs? Where can I get these parts? In a search I did find 1970 drums. I think I found the right ones. I have all the other parts, shoes, cylinders, brake kit. I did not know how bad it was till I got drums off. Would love to solve this. Thanks

Jerry

03-19-2018, 06:59 PM	#1
Preal Registered User Join Date: Jan 2016 Location: Houston Posts: 7	Eaton HO72 Brake Drums Q? Gents, I’ve read until I’m blue in the face regarding DRW Eaton HO72 drums. I know they don’t reproduce the 13x2.5 drums used on the DRW’s but I have a thought. Only thinking this much because I’m having trouble finding 14bff complete DRW Brake setups locally. The SRW 14bff used in the 73 up c30 and c20 uses a 13x2.5 Brake as well. I’m sure there are some differences in the backing plates but why wouldn’t a 13x2.5 14bff drum fit an HO72 without issue? I know the entire brake systems will mount between the two axles, how different can the backing plates really be..... Has anyone tried this type of setup. Posted via Mobile Device

03-20-2018, 07:52 AM	#2
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: Eaton HO72 Brake Drums Q? I think it may be the overall shape and dimensions that vary. Meaning where that 2.5" lays in relation to the axle flange... depth of drum body. That is the only thing I can think of that would matter. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

03-20-2018, 08:44 AM	#3
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: Eaton HO72 Brake Drums Q? There might be differences in the bearings. Just pondering since IDK __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

03-21-2018, 05:47 PM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: Eaton HO72 Brake Drums Q? I believe I was the one who brought that knowledge to this site about the 14-bolt brakes complete swap. I figured if the disc brake kits can work on an HO52/72 why not drum brakes from backing plate out, and it worked. I never tried what you are considering, but maybe it could work. Just have to get your hands on a 14-bolt FF drum and try it. I'm just wondering why people swap it all and not just the drums. Maybe it's as simple as no one has tried because the word out there is do the whole deal. The reason I tried the 14-bolt drum brake swap was I had a guy with a '72 rollback that was given my number to see if I had the drums. I didn't and he needed to get brakes on that thing like yesterday so he could get it through inspection to meet the requirements for number of trucks for a big towing contract and the brake drums flunked. We didn't have time to "try" things and I was 99.9% sure this complete swap would work... and it did. He had it through inspection in less than 24 hours from his call to me. Attached Images __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

11-25-2018, 06:52 PM	#6
Preal Registered User Join Date: Jan 2016 Location: Houston Posts: 7	Re: Eaton HO72 Brake Drums Q? Bringing this back from the dead. Had to pull the engine to fix some leaks and soon the brakes will be next on my list. Do I need to get 14 bolt dually rear brakes or will the 13x2.5 wok as will on my 71 dually?

11-26-2018, 11:08 AM	#7
StingRay Senior Member Join Date: Mar 2000 Location: Saskatoon,SK,Canada Posts: 2,476	Re: Eaton HO72 Brake Drums Q? Last time I looked Centric was making drums for the the HO72. Not cheap though. __________________ Saskatoon, Saskatchewan Canada

11-26-2018, 11:23 AM	#8
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,190	Re: Eaton HO72 Brake Drums Q? I used to put the later drums on the older model hubs. I had a machine shop drill out the stud holes & used the later model studs & nuts. George

11-26-2018, 10:55 PM	#11
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,190	Re: Eaton HO72 Brake Drums Q? Just the drums & studs. Everything else was the old original parts.

12-13-2018, 11:28 PM	#13
Preal Registered User Join Date: Jan 2016 Location: Houston Posts: 7	Re: Eaton HO72 Brake Drums Q? Problem solved! Ordered the centric rear dually drums for a 67-70 c30 and drilled out the stud holes to accommodate a 9/16 stud. Was super easy. I used the old drum as a template to ensure the drill bit was centered and the angle on the bit did the rest. Glad to not have to upgrade to 14bff brakes!

11-10-2019, 01:42 PM	#14
JerryIndy2112 Registered User Join Date: Nov 2018 Location: Indianapolis Posts: 130	Re: Eaton HO72 Brake Drums Q? I found this thread in a search. I am in the situation of having bad drums on my C3500, 1971. It has single rear wheels. I also found these drums are not made anymore. I have some questions about doing this. How do I separate the drums from the bearing hub? Will I need all new lugs? Where can I get these parts? In a search I did find 1970 drums. I think I found the right ones. I have all the other parts, shoes, cylinders, brake kit. I did not know how bad it was till I got drums off. Would love to solve this. Thanks Jerry



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