Need to do rear brakes but confused by rear end

[millsroger]

Well folks, I just googled 'GM 14 bolt brakes' and watched several you tube vids. I, for one, am not gonna go thru the whole hub thing just to work on the brakes!!! I am gonna find a dead dually in a junk yard and swap hubs and axles!!! Not gonna put dually's on the truck,, just a spacer ring behind the rims or whatever to set the wheel where it is now.

 

[3500GMC]

That's why you replace everything before you button it up.. Brakes can be adjusted from the backing plate with a brake spoon.

 

[millsroger]

Brakes need alot more attention than the hubs, I see no reason to dis-assemle the hub if I don't need to. Adjustment is the same regardless.

 

[millsroger]

My rig has JD7 brake code with 2 1/2" brakes in the rear. Everything else is rated higher than that so I decided to upgrade to slip on drums and 3 1/2". After several days of calling wrecking yards, like about 200 of them, if they have a complete rear end they don't want to split them up, $600 to a grand complete. Funny thing tho, no one had a 'core'. Not one!!! I found out that lots of burbs have slip on drums with 2 1/2" brakes. Found a guy that does only rear ends for rock hounds, said that these are what anyone serious about crawlin' wants. He cuts them down for any chassis. Point is, had lots of brake stuff left over. I got backing plates out for 3 1/2", complete with hubs and slip on drums, both sides for $200. Gotta drive 150 miles to get them. Guy says he has several drums so I can pick the best pair. Might even find a set of good shoes, just nervous about mix match on the shoes tho. Riding on 5500 lb. "E" rated tires so should be good to go.

Gonna replace the flex hoses while I'm at it, I figure to just put stock ones on. What's there went 18 years and a quarter mil miles so good nuf.

 

[3500GMC]

Welcome to the world of 100 dollar brake shoes. (get Raybestos) Don't mix and match SHOES... You are going through all the trouble to switch anyway, right?

DO NOT buy the cheapest shoe you can buy..

Check your hubs for runout. http://www.thetruckstop.us/forum/showthread.php?29181-SRW-hubs-full-floater-bad-machine-work

Do a repair sleeve on the RR, they all leak it seems, even if the surface is 'good'.. Don't risk oiling down a pair of shoes. After that happens, throw them in the junk pile.
http://www.thetruckstop.us/forum/showthread.php?32137-14-bolt-full-float-rear-axle-repair-sleeves

 

[THEFERMANATOR]

My rig has JD7 brake code with 2 1/2" brakes in the rear. Everything else is rated higher than that so I decided to upgrade to slip on drums and 3 1/2". After several days of calling wrecking yards, like about 200 of them, if they have a complete rear end they don't want to split them up, $600 to a grand complete. Funny thing tho, no one had a 'core'. Not one!!! I found out that lots of burbs have slip on drums with 2 1/2" brakes. Found a guy that does only rear ends for rock hounds, said that these are what anyone serious about crawlin' wants. He cuts them down for any chassis. Point is, had lots of brake stuff left over. I got backing plates out for 3 1/2", complete with hubs and slip on drums, both sides for $200. Gotta drive 150 miles to get them. Guy says he has several drums so I can pick the best pair. Might even find a set of good shoes, just nervous about mix match on the shoes tho. Riding on 5500 lb. "E" rated tires so should be good to go.

Gonna replace the flex hoses while I'm at it, I figure to just put stock ones on. What's there went 18 years and a quarter mil miles so good nuf.

My BURB has the slip on drums with 3 1/2" wide shoes. And do not use stock shoes or even cheapos. ONLY run the AC DELCO DURASTOPS or RAYBESTOS blue premiums(I believe they are one in the same). GM had a bulletin out to replace the rear shoes for pulling during braking as the rear stock shoe material wasn't aggressive enough. Mine had over 200K miles on them, and still looked almost new when I took them off except for heat cracks in them where they just got hot instead of stopping. And also make sure and use teh correct wheel cylinders for the shoes you go with. The 13X2.5" shoes used a 1" wheel cylinder while the larger 13X3/5" shoes used a 1 1/16" wheel cylinder. They can be interchanged. so make sure you get the right ones.

 

[millsroger]

Thanks guys, both very good tips. Did not know of the wheel cylinder diff. but makes sense. Gonna look for a matched pair of drums that have the most meat left on them and get them turned. I only use Raybestos semi-metallics--regardless of what they go in. Was saying that I thought the burbs all had the wide brakes but found out not true.

 

[THEFERMANATOR]

Thanks guys, both very good tips. Did not know of the wheel cylinder diff. but makes sense. Gonna look for a matched pair of drums that have the most meat left on them and get them turned. I only use Raybestos semi-metallics--regardless of what they go in. Was saying that I thought the burbs all had the wide brakes but found out not true.

All of the 2500 BURBS with a diesel or 454 have the 3.5" rear shoes. The 350 2500's got the 9.5" 14 bolt semi floater and only had the 2.5" wide shoes. And make sure it is teh RAYBESTOS blue shoes, not the red.

 

[millsroger]

Tnx for clarifying the burb. Yep, the reds only seem to do that--get red--:rof: (well, not quite that funny)

 

[handcannon]

Found a guy that does only rear ends for rock hounds, said that these are what anyone serious about crawlin' wants. He cuts them down for any chassis. Point is, had lots of brake stuff left over. I got backing plates out for 3 1/2", complete with hubs and slip on drums, both sides for $200. Gotta drive 150 miles to get them. Guy says he has several drums so I can pick the best pair.
Gonna replace the flex hoses while I'm at it, I figure to just put stock ones on. What's there went 18 years and a quarter mil miles so good nuf.

Can you tell me where this guy is?

A few months ago I found a burb, same vintage as my pickup, in a local pick-n-pull with the 3 1/2" brakes and pulled everything, backing plates hubs and drums. I had the drums turned and a local front end and brake shop that I always use had the shoes relined with what he says is the best working lining he's found.

I cleaned up and painted the backing plates and tried to install them, unsuccessfully. The backing plates wouldn't fit as they were inset deeper than the stock and hit the springs before seating properly on the end of the housing.

One of these days, when I get the time, I have one more thing to try to see if I can get the 3 1/2" shoes to fit. I want to see if the 3 1/2" drum will fit over the outside of the stock hub, instead of inside, and fit properly to the stock backing plate.

If that fails I would like to have this guys contact info to see what he might have. I want better brakes on my pickup and so far I've never found any affordable aftermarket options.

Don

 

[millsroger]

Really good to know that!!!! Should be going to his place this coming week. Before I go I will do some tape measure work on my truck and compare that to what he has. Will check difference between the springs and the backing plate mount, and offset in the plates. My understanding is that the hubs are the same length and bolt on so fit comes down to wheel base and mount bracket locations. If it all works out I will post contact info.

 

[millsroger]

Been burning brain cells---got a concept that might just work. Using post #16 pic as a reference for the two hubs, the drums would be in about the same place. A type being behind the flange, B type being outboard. So, if the brakes are 3 1/2 instead of 2 1/2, where does the extra 1" come from. Backing plate location and offset. Did some measuring. My backing plates have 7/8" clearance to the spring U bolts and very little offset. Apparrently the 3 1/2" backing plates have enough offset to interfere with the U bolts. Hummmmmm.

Game plan:

It appears that the flanges on the hubs are the same, just located differently. I could use the type A with the drum on the outside using the studs pressed into the flange the same way the type B is. That moves the drum about an inch out. With wider drums the inside of the drum would be at or near the right place. I could then use a spacer behind the backing plate to clear the U bolts and locate the backing plate properly to the drum.

That would locate the wheel slightly outboard of its stock position by the width of the drum. All I need to do is use the right length studs, longer backing plate retainer bolts and the right width spacer.

Mechanically, it looks like it will work, the issue would be braking pressure for stopping power. I do not know whether the proportioning valve will work properly to get full effectiveness from the larger rear brakes. I do know that bigger brakes is usually better.

 

[handcannon]

What you posted is similar to what I had going through my mind. I just have been too busy lately with doing things around the place that need done before fall rains hit to do any thing.

Kepp us posted how things go.

Don

 

[handcannon]

And also make sure and use teh correct wheel cylinders for the shoes you go with. The 13X2.5" shoes used a 1" wheel cylinder while the larger 13X3/5" shoes used a 1 1/16" wheel cylinder. They can be interchanged. so make sure you get the right ones.

I went back and did some re-reading of previous posts as I had something nagging me about wheel cylinders and this is what I found. Thanks ferm for posting this info.

I already have cylinders so I'll have to check out what I got. They're probably the 1" cylinders.

Don

 

[millsroger]

One of the Q's I have--don't have the backing plates yet--since the center of the shoes is a different distance out does the backing plate have a boss to move the wheel cylinder out or does the wheel cylinder have the offset cast in.

 

[handcannon]

I'm not at home right now so I'll try to answer from memory.

As I remember it, the backing plate has the axle mounting area set out and the outer ring of the plate sets in towards the springs, like an upside down cup. This puts the cylinder about center of the shoes. The outer ring hits the springs before the axle mounting surface of the plate can touch the axle.

Don

 

[millsroger]

Good description Don, kinda what I thought. So, I figure a spacer block behind the backing plate to let the outer ring clear the U bolts and align with the drum. BUT, it also occurs to me that the original backing plate might work too IF the wheel cylinder offest from the plate can allow it to line up with the wider shoes. I guess I'll just have to get all the pieces parts together and see how to fit them.

In the FWIW department, I did the fronts. Had an issue with what felt like warping rotors or drums--kinda shuddering and once around surging after I applied the brakes--not ABS shudder as that's much faster. When I pulled the wheels the driver side inboard pad was within 1/16" of gone, outer was near 1/2. Pass side was even. Found the puck was sticking in the caliper. Got kits and rebuilt both sides. Pins and sleeves were not worn so just cleaned and lubed with molly based spray on Lock EZE. Replaced both flex lines with GM. Also found brake fluid very, very dark but no water or corrosion. I got a gallon of brake fluid and a turkey baster, simply sucked out the bad, then pumped new thru until I had new fluid all the way at all four corners. I used synthetic high temp racing stuff that I had from my rally days. Made for Bembo. Anyway, shudder gone. Watch for even pad wear, if not then you have a problem.

 

[tanman_2006]

Every time we put pads on my dads fords he has to replace the pins and sleeves. Usually he has to get atleast one new caliper because they wont free up. GM has a better design but it still needs to be checked whenever apart.

 

[millsroger]

Per the maint. log from the PO, meticulous, brakes 34k ago, about half used except for the sticky caliper. Prolly new pins and sleeves at that time. I agree, need to check everything.

 

[handcannon]

I'm home now so I thought I'd post some pics of what I've got.

1-- Back side of backing plate. Ignore the sawdust, I'm a woodbutcher.

2-- Here's the inset of the mounting surface. It's just shy of 1 15/16".

3-- Here's the front side. That is a new cylinder, just been setting in an unheated building.

4-- Here's the hub that I got off the burb, along with the rest of the brake parts. It's hard to read the tape, but it is 2 5/8" from the flange surface to the end of the hub.

Maybe this will be of some help when you compare parts.

Don