Need 1972 C30 rear brake shoe and seal data

[CCCC]

While visiting the big city I need to obtain rear brake shoes for my 72 C30 with the long wheelbase (173" I think) and it has the heaviest factory rear setup for that year. It is a chassis mount camper/motorhome. Just can't trust these young yahoos in the parts stores to know the correct parts for our old Chevs.

Am 200 miles from the truck and cannot dismantle the rear axle setup right now in order to get sizes etc., and need to get the parts purchased. I think the shoes for those big drums on the heavy 1 ton setup are 15" x 4", but sure would appreciate confirmation/correct info from someone who knows these C30s.

Also want to buy the lube seal that fits into the hub/brake drum if you have a mfr. part number or size (ID/OD) on that one.

Any help will be much appreciated.
Thanks.

[SS Tim]

If I knew I don't remember, do you have an HO72 (8-lug) or an HO110 (10-lug) rear axle?

While you are waiting for a cross check you can look up the parts on www.gmpartswiki.com Brake and rear end parts are in Group 5.000 around page 860 in the May 79 catalog.

[71Dually]

Greetings CCCC,

SS Tim makes a good point regarding axle size. That is important to know if it is an Eaton HO72 or HO110 as that will affect your parts. They are different parts. Thanks Tim for that important fact, it totally slipped my mind.

I have a 1971 C30 Cab Chassis truck. I have the HO72 7,200 lb. axle with the 8 wheel studs

Here are the part numbers for the parts on my axle.

Hub Wheel Seals - National Oil Seals 2081
Axle Flange Gasket - Felpro 55350
Brake Hardware - Carlson H7027
Brake Shoes - Wagner PAB320R

A great place to find replacement aftermarket part numbers online is Rockauto.

If you do have an HO72 before you buy everything check to make sure your Eaton rear drums are serviceable. If the drums are out of spec they are no longer available. I did mine only to find my drums were out of spec after all the work was done. My drums are also out of round. I have an annoying tic, tic, tic every time the hub rotates as the drum catches the shoe and lifts it from the anchor pin and the pullback spring snaps it back. They also lock up fairly easily. I go lightly on my brakes anyway so I rarely lock them up unless its a panic or hard stop situation.

A work around for the obsolete Eaton HO72 drums is to convert the rear brakes to 73-88 14BFF backing plate and drums. They are a direct bolt in and solve the problem of difficult to find obsolete parts.

The 14BFF brakes are available in two sizes. 13 X 2-1/2" is the same size as the HO72 Eaton brakes. The other larger size is 13" X 3-1/2" that was on JB8 optioned trucks. I have done the JB8 swap on a spare Eaton axle I have and it fits perfect. The only issue I see is the wheel cylinders are different and I need to fabricate rear hard brake lines to fit the smaller fitting size on the 14BFF wheel cylinders.

I have to do this since the bore size of the JB8 wheel cylinders are 1-3/16" compared to the Eaton's 1-1/8" bore size. With the smaller 13 X 2-1/2" 14BFF Brakes the wheels cylinders are the same 1-1/8" bore of the Eaton's. I believe if someone uses the narrower brakes they can swap the Eaton wheel cylinders and avoid hard line fabrication.

If you have an HO72 and do decide to do the swap grab the longer wheel studs from the 14BFF axle to use in the conversion. The drum mounting flange on the 14BFF drums is a little thicker than the Eaton drums and the longer studs help compensate for that.

In looking for the parts for the swap look for 14 bolt axles with the bolt on pinion bearing retainer. That is what I was told by a reputable rear end rebuilder in my area named Hooper's Rear End Exchange. Anthony at Hooper's was a lot of help with my parts search and interchange information. He really knows his stuff.

Here's a link to a topic I participated in that has a picture showing the the 14BFF & Eaton drum thickness differences. See post #9:

http://67-72chevytrucks.com/vboard/s...d.php?t=623663

Here's a link to an Eaton 14BFF swap topic that helped me here on the forum:

http://67-72chevytrucks.com/vboard/s...d.php?t=536119

Not touched on in the above swap topic is the Eaton axle oil slinger and its proper function. The Eaton's lubricate the hub bearings with gear oil from the axle. The slingers are there to prevent slight oil seepage from contaminating the brake linings. The Eaton drums have two holes on the drums that are part of this system that the 14BFF do not have. So with the conversion I would recommend these holes be drilled in the drums and the inner oil slingers be utilized to retain this design function. Without the holes in the drums the stray oil seepage has nowhere to escape.

Touching on this hub bearing lubrication please be sure to pre lube your hub bearings with a little grease (not much) and gear oil when they are reassembled. You also need to raise each side of the axle 6 inches above the other to lube the bearings as part of the reassembly procedure so the bearings are not initially starved of lubrication when placed back into service. The factory service manual explains the procedure.

A few pics to help.

Hub seals



Axle Flange Gaskets



Brake Hardware (You only need one box to do the complete axle)



Brake Shoes



Eaton HO72 with 13 X 3-1/2" 14BFF Brakes



Eaton drum with oil slinger holes (center top and botom)



14BFF drum without oil slinger holes



Drum flanges mated together showing the hole location to be drilled in the 14BFF frames to retain the oil slinger design (center left and right)



An image showing the difference in the 3-1/2" and 2-1/2" brake shoes.
3-1/2" 14BFF JB8 on the left, 2-1/2" Eaton HO72 on the right



14 bolt full floating axle with bolt on pinion bearing retainer (The axle I pulled my stuff from)



14 bolt full floating rear cover (an obscured view)



Hope this helps, good luck with your brakes. If you do the swap please let us know how it went.

Best regards.

[Petie724x4]

I don't mean to hijack, but I will have to service the rear end on my 1ton sometime in the future and I'm just curious about the HO110. I have the 10lug rear (and 5 front). Is there a listing for brake parts, or am I out of luck...

[SS Tim]

Originally Posted by Petie724x4

I don't mean to hijack, but I will have to service the rear end on my 1ton sometime in the future and I'm just curious about the HO110. I have the 10lug rear (and 5 front). Is there a listing for brake parts, or am I out of luck...

There is a link in my post (#2) to the GM parts wiki. Along with it is the group number 5.000 where most of the rear axle parts can be found. While not a current GM offering list it is a place to identify what you need and part numbers to cross from.

[CCCC]

Thanks to all for the info so far - very helpful, and especially thanks to 71 Dually for the extensive info and great photos. As soon as I am certain about the rear axle data (tomorrow AM) I will be back on here to try pinning down the specifics.

I replaced an axle seal on this truck a few years ago and would have sworn that the brake shoes were the much bigger ones (maybe close to 4" wide), but that old vision/memory does not seem to fit with some of the comments/photos here. So, kindly stay with me here for another day or so until my data is better and this will get done.

Thanks again.

[SS Tim]

The 67-70 C30 w/11K rear axle is shown as having 15x4" rear shoes. The size is not indicated for 71-72 C30 w/11K rear axle in the parts manual.
However there are two different part numbers for the two applications.

[71Dually]

A Canadian version of the Chevy - GMC Truck (Light Duty) 1965-1975 Master Parts Catalogue published in May 1981 shows the 71-73 11,000 lb. axle has the same part number as a 74-75 P30 w/15" x 4" brakes.

I would figure if they are the same part number they would be the same size.

This is the cover of the catalogue I used:



Here's a pic for the rear brake shoe part number from that catalogue


The 67-70 shoes and the 71-72 shoes also have different numbers in this catalogue. The 67-70 shoes are #3881550. This concurs with the info SS Tim has posted regarding the different part numbers.

The catalogue also shows the same brake drum (Group 5.809, Part #3996643) for a 71 11,0000 lb. axle and the 74-75 P30 11,000 lb. axle.

If you do have the 11,000 lb. axle I'm pretty sure the parts I listed will not fit, they are all for a 7,200 lb. axle. I also don't know if a brake drum is currently available for a 71 11,000 lb. axle.

Rockauto.com shows the shoes are available for the 11.000 lb. axles 15" X 4" brakes (http://www.rockauto.com/catalog/more...213&cc=1033579) but does not list the drums. That is probably a sign the drums are no longer available. I don't know anything about a brake swap for the 11,000 lb axle but search the forums as someone may know or have posted about it. If you have an Eaton axle use HO110 in your search terms to denote the 11,000 lb. axle.

In addition to GM parts wiki for original GM part numbers, Rockauto and O'Reilly's are sources to check for current availability and cross reference. Stepvanparts.com is also a source for some interchangeable P30 & C30 parts.

I'm currently using the above resources with good success to research a JB8 brake conversion for my 71 C30.

Also of note. from your signature it looks like you have quite a collection and would appear knowledgable in what you have.

Please pardon my question but does your motorhome look similar to this?


Or is it a full bodied class A motorhome?

The above pictured motorhome is built on a cab chassis truck and uses C30 truck parts. The Class A motorhomes are built on Motor Home Chassis's and I found they sometimes require different parts than the cab chassis trucks. The P30 is the closest relative to a motorhome chassis rather than the C30. Some C30 parts are interchangeable on the MHC but not all so please double check the applications so you get the right parts.

If you have a van bodied front end motor home then it is built on a G30 chassis and again would have some parts unique to the "G" van series.

[CCCC]

Thanks again 71 Dually and, yes, my MoHome is the same cab/chassis configuration as yours - a Mitchell camper body on a C30 cab/chassis and not the P30 van type.

Mine has the 8 lug wheel setup and 8 bolts on the axle housing, with 10 bolts on the diff cover. From under the vehicle it also looks like the sitting setup you pictured so I am almost certain that if the one you pictured is an H072, mine is as well.

BUT - my old visual memory of those shoes says they were more like the the 15" x 4" shoes shown. So, now am wondering if Chev/GMC used two different depth brake drums on those H072 axles - maybe used smaller ones with shoes about like 13"x2.5" which i have installed on some 3/4 ton trucks.

Yes, I am in doubt and a bit confused about the brake shoe size on this one and will really be pleased if a more experienced person here can provide clarity before I have to pull an axle/drum just to find out - because I need to do the actual work in a place where I can't leave the truck sitting while waiting for parts to get here via mail or courier.

I am now going to do some research on the Model # (CE31403) with 157" wheel base to see if there is an answer there.

To all - thanks for the help so far. More later.

[SS Tim]

On a C30 the 13" x 2-1/2" brakes were standard as a SRW and this included the 157" wb. The two brake options would be with the R05 DRW and the H22 11K rear axle. However some deeper checking is showing that the H22 was not available with the 400 or automatic and included a 6.17 ratio.
It would seem that your truck would indeed have a H072 unless it is some fleet option rear.

[CCCC]

Thanks, Tim, for the extra digging and that data page. This truck could very well have been equipped as a fleet option" deal in that the company up in CO that built these motor homes (Mitchell) apparently purchased several cab/chassis units at a time, but there is no evidence of such.

I need to find some photos on the net or some ID markings on the equipment to i can determine if it is 7,500# or 11,000#.

I'll be back.

[special-K]

The 11k# rear axle is the 10-lug and the HO72 is 8-lug. I'm sure you don't have the 11k. The 11k# rear is a big mutha up under the 30-series,being a medium duty axle. No mistaking it. It would never have come with an automatic in a 30-series,as pointed out,anyway.

[71Dually]

Thank you for the information on your truck. That will help. A stock or modified system will determine the manner to use to determine your brake size.

Stock methods. Check your SPID and ID tag on the driver door sill post. Check the Bendix number stamped on the backing plates. Are your wheels original? If they are original, what size tires / wheels are they? The answers to these questions will help determine your brake size.

I have an unmolested, 10,000 lb. as manufactured GVW rated, model CE31403 truck. As previously stated in post #3 it's a 1971, 157" WB, C30 cab chassis with a factory DRW HO72 with 13" X 2-1/2" rear brakes. The motorhome picture in post #8 of this thread is indeed my truck. The motorhome has since been removed and a flat bed has been installed.

I know all the above information because of the information on my door sill data tag and SPID. My truck has a 10,000 lb. GVW (as manufactured) stamped on the door sill tag and RPO codes F60 Heavy Front Springs, R05 DR Wheel Conversion and S76 16X550 F Wheel along with the model # and wheel base on the SPID. In comparison an HO110 axle would have an 11,000 lb. or 14,000 lb. GVW (as manufactured) stamped on the door sill tag. The SPID would have an RPO code of H22 in place of both F60 Front Springs and R05 DRW codes and would list one of the following RPO wheel codes of R90, R97, R98 or R99 in place of the S76 code for the 16" wheels.

A pic of my door sill tag:


The "*Maximum Capability" seen on the tag above does not necessarily reflect how a truck is actually equipped. Instead it is the capability obtainable with optional equipment specified in the owners manual. Per my owners manual for my truck to achieve it's maximum GVW capability it would need the RPO H22 axle (an HO110) and 19.5" 10 lug wheels / tires (RPO R97, R98 or R99) to attain this maximum 14,000 lb. GVW rating. With the HO110 axle and 18" 10 lug wheels / tires (RPO R90) the truck would have an 11,000 lb. GVW rating. Since my truck has a 10,000 lb. GVW (as manufactured) rating on the door sill tag according to the factory literature it is equipped with the HO72 and 16" 8 lug wheels from the factory. My trucks SPID coincides with this factory literature.

From the factory an unmodified HO72 axle will have 13" X 2-1/2" brakes, 8 wheel studs and 16" or 16.5" wheels and tires. The numbers stamped on my factory 13" X 2-1/2" backing plates are "Bendix 324636-L" & "Bendix 324636-R."

Pics of the number stamped on an original 13" X 2-1/2" HO72 backing plate. The backing plate was pulled by me from an original 71-72 axle and the arrow shows where the number is stamped:


Closer detail of the number on the same 13" X 2.5" HO72 backing plate pictured above. The number is actually stamped upside down when the backing plate is installed on the truck. Note the position of the star wheel brake adjuster hole in the two pics:


Since I do not have an HO110 axle I can only speculate what it has from the information available to me. This available information is the Master Parts Catalogue available on GMpartswiki, the factory truck specification literature from the GM Heritage Center (Link Here), Google search and the internet. According to this information in stock configuration the HO110 axle should have 15" X 4" brakes, 10 wheel studs and 18" or 19.5" wheels and tires. I do not know the number stamped on the backing plates.

All of the items on my door sill tag, SPID and the actual parts installed on my truck point to my truck and rear axle being unmolested. I know the history of my truck back to the early 80's. I have the two PO's documentation and receipts to support that history. The truck had 38,615 miles on the odometer when I purchased it last October. According to the documentation in my possession the truck had just under 1,000 miles logged on the odometer in the 11 years prior to my purchase. The overall condition of all the factory high wear items in the interior of the truck indicate the odometer has not turned over. This indicates it is a genuinely low mileage vehicle and very likely unmodified.

The only owner modification I'm aware of in the rear axle area of my truck was a rear leaf spring upgrade with the addition of 4 additional leafs per side in 1984. I have the receipt for the parts and the truck has evidence of this alteration in place with the added springs and a modified factory spacer block. The modification basically consists of doubling up the four inner springs and a cut and weld job to shorten the spacer block. There are modifications on other areas of the truck but these were mostly done by the original motorhome manufacturer and do not effect the rear axle.

If the RPO codes F60, R05 and S76 on my truck's SPID and the 10,000 lb. GVW on the door sill tag pictured above match the information on your trucks tags then I would say it is very likely you have an HO72 and 13" X 2-1/2" brakes if everything on your motorhome is intact as it came from the factory.

A modified truck is a whole different animal. If it is modified then other steps to identify the modification is in order. The following will also help in the event that your SPID and/or door sill data tag information is not available.

You don't need to pull the hub / drum to find out your brake size (but without question that is the most accurate method). Some things will point you to your brake size.

Pull the rear wheel. The drum should have a maximum diameter specification cast into it. What is this specification? My 13" X 2-1/2" HO72 brake brake drums say "Max Dia 13.09 In."

Measure everything with a tape measure, approximate measurements should suffice as there is a 2" difference between the two diameters. Measure the drum, if it's a 15" drum it will measure about 16" on the diameter of the exterior drum surfaces which coincides with the inner shoe contact area. A 13" drum will measure about 14". Measure the backing plates best you can. With 13" brakes the backing plates should measure about 14" on the diameter. The 15" brakes should measure about 16". Measure the width of the shoes contact area on the drum. This can be approximated on the outside. There will definitely be a big difference between 2-1/2" and 4" wide brakes. If your measurement is 3" to 3-1/2" then it won't accept a 4" wide shoe.

You really don't need a tape, eyeball the distance between the drum and the wheels. With 16" wheels the distance will be just under an inch for 13" brakes. 16" wheels will not fit on 15" X 4" brake drums. The distance of the 18" or 19.5" wheels should be about 1" to 2" I figure depending on the wheel. But the 15" brakes have 10 lug nuts and thats an easy check too.

As you can see from the picture in post #3 the Eaton HO72 axles will accept the later model 14 Bolt full float hub axle (14BFF) brakes. The stock Eaton drum is different from the 14BFF drums. The Eaton drums are smooth, the 14BFF drums have cooling fins to dissipate heat.

Here is a pic of the two different drums, the Eaton 13" X 2-1/2" drum is on the top and a 13" X 3-1/2" 14BFF drum is on the bottom.



I've located pictures of an HO110 axle and it has 10 wheel studs. It does have obvious differences from an HO72. Heres a link to those pictures: http://www.pirate4x4.com/forum/chevy...10-thread.html

Do you have a picture of your SPID and the door post tag? Do you have pictures of your rear end? Do you have pictures of your brake drums? Is it possible to post pictures of these items? That will help identify what you have. Without pictures its a little difficult to identify the rear end and brakes. Kind of like watching a silent movie with a blindfold on.

If pictures are unavailable then posting the SPID's RPO codes, the data tags GVW's and the stamped backing plate numbers are likely necessary to get closer to an ID of your brakes thru this topic. It's still best to post pics so we can see what you have to assist in identifying it and it's brake size.

A measuring tape will definitely tell the tale of the brake size. The measuring tape will also verify the information on the data tag and SPID.

This post contains a lot of details, information and methodology. I do hope it is not to convoluted or difficult to understand.

Hopefully this all helps, please keep us posted.

[CCCC]

71 Dually - you say "This post contains a lot of details, information and methodology. I do hope it is not to convoluted or difficult to understand." It is a great post for me and completely understandable. I had already done the whole spid and doorplate info routine and now will go to the number on the backing plate (had no idea that it is there and even a look through the dirt/dust didn't reveal anything when I crawled under there yesterday).

special-K - thanks for your post - that logic is right on the mark.

I think that the biggest problem here is a visual memory from the last time I had one of my C30 axle/drum setups apart. In my mind I am seeing that big finned drum up on the bench while I was installing the new seal and the wider brake shoes from which I cleaned the lube - but - when I consider the tag data and read your comments, am thinking that vision must be a figment of my imagination. I do try to learn as much as possible and remember details every time I do some repair like this, but old age must be setting in.

Due to distance/time factors, have been stubborn about wanting all replacement parts in hand before I tear down. But, am thinking it best to go out there and get it apart even though it will sit in an undesirable place for a while.

You all have been most gracious and helpful - definitely will post the outcomes here. Thanks.

[Big Block]

Great post! Good information. Have 1972 C30 dump truck and it needs brake work now. Thanks guys.

[CCCC]

OK - the rear of the 72 C30 MoHome is apart and definitely an Eaton H072 with 13x2.5" shoes. Also figured out that my "memory" of the larger drums/shoes was with a similar but heavier truck I repaired here in the garage zbout 5 years ago. I do like these C30s and even a bit bigger.

One more inquiry - the leaky axle seal I am replacing allowed some gear oil to get onto the brake shoes/drums. This afternoon I cleaned it all with brake parts cleaner and a lot of scrubbing on the shoes. The shoes are only about 15% worn and the drums are clean/smooth. Will examine the shoes carefully in the AM when all dried out.

Has anyone had this experience - that is, shoes that got coated with lube - and will a good cleaning/scuffing be likely to keep them useful? Or, is replacement a must.

Thanks again.

[71Dually]

Greetings CCCC,

Thank you for the update.

Originally Posted by CCCC

OK... Has anyone had this experience - that is, shoes that got coated with lube...

Yes sir, I sure have.

Here's a tell tale sign pic:

Originally Posted by CCCC

...is replacement a must.

Mandatory, junk the shoes, they are contaminated, the bonding material in the linings is compromised and the required friction properties are gone. Your rear brakes will pull and lockup. Ever slide sideways from rear brake lockup? Ever do a brody on a Schwinn sting ray? Don't risk your classic MoHo or personal well being to save $60 bucks on the shoes. How do your drums look for specs? Maximum diameter is 13.09" so if a tape reads 13-1/8" (13.125) they are likely out of spec.

When you do go to get your parts take the drums and have them checked. Make sure they check them for out of round also. Leave the hubs and drums assembled. I know, they are real heavy but some places require them assembled in order to turn them, it's a lot more accurate machining them that way also.

If they can still be turned expect them to have to be sent out because "we can't turn big truck drums here". Find out where they send them and take them yourself, it's faster and won't include a middleman "markup." If they won't tell you where they send them I'd show them all the other parts I was looking to buy. Their business is there to help and sometimes "normal" customer service requires a referral in my opinion.

If your drums are out of spec consider the 14BFF brake swap. Serviceable Eaton drums are real hard to find and very likely expensive if you can find them at all. An extra added bonus with the swap is you will have more finned drums to remember later down the road.

Do not buy any parts until you have the drums checked. Ask me how I know, I bought all the Eaton stuff before checking my drums, installed everything and then checked the drums. They were beyond specs and out of round. But I needed the truck to run so I could pick up a flat bed I had bought so I installed the out of spec drums anyway and made the trip. Now I have to buy all the same (but different) parts over again to do the 14BFF brake swap.

If you do decide to do the brake swap, source the backing plates at a local JY. The 14BFF axles are quite common and backing plates are all over the place. A fellow forum member may even have a set. When you do get them make sure they are not bent and the brake shoe contact areas are not excessively worn. Backing plates may even be available new (I have never checked that but I do know that some are). For bare used ones I wouldn't pay more than $35.00 each at a full service yard. They should run no more than $15.00 each at a Pick-Your-Part yard. My local PYP yards charge $8.00 each for bare plates.

Make sure you get the BP's from a DRW truck. I've been told the SRW plates will work but I have not verified this. You may want to grab complete plates with shoes, springs, levers, wheel cylinders etc... that way you'll have all the parts required to check that the new parts are the same. You will also have anything that might not be immediately available like equalizers, emergency brake levers etc... if you buy the assembled backing plate. Expect to pay more for a BP with shoes, springs etc... compared to a bare plate. Price aside, the advantage of pulling parts from PYP yards gives you the advantage that you know what the parts came from vs. something that looks close grabbed from a big pile of parts.

One point to consider when shopping for backing plates. Most folks won't want to separate their brakes from a rear end unless the rear end has problems inside. A serviceable axle without brakes is harder to sell than a complete one. Pic-A-Part yards don't care, full service yards will charge even more $'s for the part if they have to pull them from a good complete axle. Craigslist sellers may not want to separate them at all.

Make sure you go to the parts store after the junk yard, then you will be all dirty and they will think you know what you are doing. They may even sell you the right parts. Oh, wait, that has never helped me before, they still try to sell me wrong parts. My normal conversations with the parts guys sometimes include the following spiels: "Why do you want to know if it has air conditioning when I only want rear wheel seals and axle flange gaskets sir?" and "Why do you need to know my year, make, model, engine, transmission and if it has power windows to look it up when all I want is a valve stem cap?" And "What!!! What do you mean 'what's a axle flange gasket?' How did you get that ASE certified parts pro patch on your shirt and not know what a truck axle flange is?" I'm a real monster over computer literate ignorance at the parts counter.

When you buy your parts include new 14BFF drums and some brake line tubing to make the rear lines while you are at the AP store. A double flare tool and tubing bender is mandatory when fabricating brake lines. Well, maybe not the bender so much but it will help to prevent kinking the new brake lines. A kinked brake line sounds like it would be an additional road trip into town for you. My parts store is about 1-1/2 miles round trip so it's only a couple gallons of gas in my C30 for the trip. Your milage may vary.

Replace the rear rubber hose at the same time you do all this, then you can feel safe and wont have to bleed the brakes twice. You will also be able to make sure you have the right flare nut fittings on your newly fabricated brake lines that fit the rubber hose end. Also check the wheel cylinder fitting size as the may be different from the hose. Last but not least, don't forget the longer 73 and up Dorman #610-193 wheel studs.

My caveat in all this is: I have not looked into the original emergency brake cables bolting up to the backing plates in this conversion. They look like they will fit but I have done nothing further with the cables than glance at the ones on my truck. I have only taken an even shorter glance at the 14BFF cables but my initial impression is they should be compatible. In my extensive research on this swap I have not read anything to the contrary to cable fitment and have no reason to believe they will not interchange. Besides, I needed a reason to throw in a caveat since I haven't posted one yet.

All the parts for the swap would be 73-86 DRW parts. Also check DRW G & P 30's (1-ton Cargo Box Vans (looks like a "Uhaul" truck) and Step Vans (looks like an ice cream truck)). The 14BFF DRW brakes are available in both 13" X 2-1/2" and 13" X 3-1/2" sizes. The brakes pictured on the axle in my previous post here in this topic are 3-1/2" ones pulled from a 1982 step van (P30).

Read this topic for more info on the brake swap: http://67-72chevytrucks.com/vboard/s...d.php?t=536119

I figure with JY backing plates and all new brake parts including drums all this should run about $350 - $400 if you go the Manny Moe And Jack the price up type store route. RockAuto will save you money.

In closing, and trying not to be to presumptuous on your skill level, please, pre lube your hub bearings when you reassemble everything. If you don't, you can ruin the axle housing and the very expensive hub bearings. The factory manual details the mandatory procedure to pre lube them.

Good luck. Please keep us posted or check back if you would like more input.

P.S.

Where are the pictures?

We all like pictures.

[CCCC]

OK - got this job finished in style - just late reporting. 71 Dually was a BIG help with pics and info (Thanks !) - made the thread a ton better.

The HO72 parts got Id'd and came together nicely, drums were a mess but cleaned up fine and were in spec, and the new shoes went in nicely (even if a bit tricky with a couple of pieces). All adjusted up well and the big wagon has good braking.

This all started with a lousy/leaking inner seal and not much way to know until some tell-tale shows on the inside of the wheel/tire. It's a very good rear diff/exle setup, however. Strong and durable.

Thanks for all of the help and thoughts.

[Z28young]

Good info on this thread. Does anyone have the service specs for the HO72 drums? If I change over to the 14 bolt backing plates and drums what year range of 14 bolt do I need to look for? I have been reading a ton of info on this, but still a little confused on what I need to get to do the HO72 to 14 bolt brake swap if I have to. I have a 72 C30 Cab Chassis dually with an HO72.