14 Bolt Full Floater Brakes

[hotrodpc]

Not even sure anyone is interested in this ugly truck, or a truck this old here. Seems to be site for nice newer trucks. Not sure its being posted in the right category either, but that is what Mods are for right? Moving threads or deleting them if they don't fit. This is from my 84 C2500 Truck that I got for $100 with a rebuilt 454 and blown Turbo 400. I had been having to fill that tiny rear brake resevoir about every other day, so I knew I had a leak of some kind. I was outside at work and noticed a puddle inside the right rear tire. Thought, damn if thats my leak, its a bad one. Sure enough, brake fluid dripping out of the drum. That day when I got home, I called for parts availabilty and prices immediatly. Wheel cylinder rebuild kit was $6, which what I usually do. When I noticed the NEW Wheel Cylinder with a Limited Lifetime warranty for $13 guess what I decided to do??? No need to worry if its pitted with rust, no need to hone it, no need to replace the pistons if needed, and LLT warranty, so sure, I bought new wheel cylinders and save a little labor too. Had a bit of a problem. It has been years since I worked on a Full Float rear axle. I was looking for the tangs to bend over to get the hub not off. There wasn't one. Posted on another site asking how to get it off, no response, and I didn't have time to wait. Maybe I should have posted here. I know there is at least one 14 bolt Full Float guru here. Finally I noticed the keeper retaining ring, popped it off with ease using a standard screwdriver, backed the nut off the keyway, and the keyway slides out easily. What I found was extremely saturated shoes as expected, but the shoes were good and lots of use left. Maybe only 25% wear. Drums did not even have a glaze on them and were nice and smooth, looking like a recent turn job. Being that I did not replace the shoes or turn the drums, I just bought 2 wheel cylinders, 2 Timken wheel seals and 2 cans of CRC brake clean to clean off the shoes and saturation off the backing plate. Total cost of $47 including tax. Here is what the bad leaking side looked like.

 

[hotrodpc]

I was pressed for time and daylight, so I don't feel I got this as clean as I wanted it, but the important parts are very clean and functional. Shoes seem to have cleaned up and dried nicely, drums were awesome. The adjuster threads were stuck. Took a bit of doing, but I got them unstuck and lubed the threads with white lithium grease so that they will contiue to adjust properly put it all together. Used my 13yo son for, Pump it, Hold it, brake bleeding.
Nice firm solid pedal way up high, brakes working flawless now without leaks. Some very touchy brakes now. Don't touch the pedal unless you really wanna stop. 75% use left on the shoes, 13x2 1/2inch and those biggo meaty things do not wear fast, so there is years of brakes left. Checked the brake fluid today since I did this job 5 days ago. Hasn't lost a drop of fluid. Master is full both front and rear resevoirs.

Just thought I'd post about this, since I had not done a full float in so long and was not familiar with this type of retainer for the hub nut, that someone else may use the info someday too if they find it. It was a piece of cake job, no special tools required at all. Once I got it figured out, and the first back together, the 2nd side took me a total of 30 minutes, and that is likely slow, but once I realized I was easily going to be the daylight, I did not get in any hurry.

 

[hotrodpc]

Here is a list of instructions for how to remove the Full Float rear hub on 80's model GM 14 bolt rear end.

1. Chock block front wheels so vehicile doesn't roll. (E-Brake not working of course w/ Rear wheels off the ground).
2. Jack up rear wheels and support rear end on Jack Stands. (Feel Free to skip the Jack Stand step if you don't like your life)
3. Remove Wheels
4. Removie 8 bolts around axle flange, then pull floating axle out of rear end.
5. Using a medium screwdriver, remove retainer from hub nut threads. (Very similar to snap ring).
6. Using the same medium screwdriver and small hammer, put the screwdriver in one of the hub nut notches and tap lightly with hammer to move hub nut off of the keyway just enough so that the keyway has no pressure on it whatsoever. (Supposed to use a specail notched socket to remove this nut, it was not necessary at all. Nut backed off with very little force.)
7. Using needlenose pliers slide keyway out of its groove of the axle tube.
8. Remove hub nut. I just used the screwdriver in one of the notches and spun it out with ease without any damage to the nut or threads at all, where this special socket is supposed to be used.
9. There you go. That's it. Slide the drum off the brake shoes. Mine slid off with ease being that the brakes had not dug into the drum, and were not adjusted very tight since the adjusters were stuck, so depending on how bad you failed to maintain you vehicle, will decide how much you have to fight to the get the drum off the shoes, but there is nothing else holding the drum on at this point.
10. From this point, its just like any other brake job. Purpose here was only to remove the drum and hub, so you are on your own from here. I will add, be sure to replace your wheel seals if doing a brake job on a full floating axle. Many people like to skip this step, but its ridiculous to do so. The wheel seals were $6 each. Like the person who did these brakes not long ago obviously, did not think as old as this vehicle is, to replace the wheel cylinders too so now I had to do it. All good though. Now I know the condition of the rear brakes and they will last along time being done properly now.

 

[dirtyoldman]

Very good post There are MANY full float rears here.My '95 is one and I'll be doing a brake job on it soon.A ''how to'' thread is always helpfull.

Man,that was one wet wheel,huh? Sometimes when the shoes are worn down so much and the wheel cylinder has extended itself and then when pushing the rubber cups back in with the new shoes they get messed up,then they leak.When I do my brake job I'll be replacing the cylinders

 

[daddy]

Nice write-up, Thanks!

 

[hotrodpc]

Glad someone likes it. Maybe somebody else will get to use it, but you know I am getting old, and by the time this truck needs rear brakes again, I'd likley forget how, so I might get to use it myself. Sometimes I do these forum things for notes to myself and other people benefit too. Seems you guys on this site all have newer vehicles though, and most of the stuff I have like this is for the older models. Someday I get energectic, I may post some pics of a Turbo400 I rebuilt for this truck. It was a nasty job since this trans came apart towing a loaded trailer on a move across 2 states and it was burnt badly. This was how I ended up with the truck for $100.
Replacing the cylinders is a Good Idea gramps. Especially on a rear end like that. Reason I think so, is because those brakes would usually last so long, it would stand a good chance on the 2nd or 3rd pair of shoes, they are likely to outlast the cylinders if you don't, even if you cylinders look great at the time you do the brakes.

 

[Stumpuller6.5]

good right up, setting the nut tension is important, tighten untill snug then back off to the next available slot for the key.

the bearing design should not be under pressure, it will cause rapid wear of the bearings, and due to the design, if the alxe bearings fail the metal can find its way into the center housing.

 

[dirtyoldman]

I did the rear brakes on my '77 GMC (3/4t,full floater,Camper Special) a few years ago and were still working great up to the end of the truck,so good in fact my son had to stop quick to avoid hitting a car at a red light that he put his entire foot(size 14)on the pedal and locked 'em and slid into a tree.He said they locked up,yeah I said,when you push hard on the pedal they tend to do that.No ABS here

Great truck,still miss it

 

[hotrodpc]

good right up, setting the nut tension is important, tighten untill snug then back off to the next available slot for the key.

the bearing design should not be under pressure, it will cause rapid wear of the bearings, and due to the design, if the alxe bearings fail the metal can find its way into the center housing.

Good Additional Info. That is exactly how I did it. Drum was turning nice and smooth and NO additional drag from tightening the hub nut. This was actually easier that I had remembered. The last full float rear ends I put brakes on years and years ago, was the type with a bend over tangs. It seems to me it also had 2 hub nuts, one was the main one, then another one that went over that to work as a lock nut, then you bent the tang over to keep the lock hub nut from backing off. Also I do not recall their being a keyway in that older system. Could be wrong, but I do not recall it. Now that I think about it, It seems I remember you put on hub nut, then the tanged spacer has a tab on it, that fit in a groove on the axle tube similar to where the keyway would go, then you your locking 2nd hub nut over that tanged spacer, snugged it lock the hub nut, then bent one of the tangs over to keep the lock nut from spinning. So if you ever get an older system, that is what you can expect. If I am wrong just remember how much paid for that info. I have slept many many times since I last worked on one those.

 

[hotrodpc]

I did the rear brakes on my '77 GMC (3/4t,full floater,Camper Special) a few years ago and were still working great up to the end of the truck,so good in fact my son had to stop quick to avoid hitting a car at a red light that he put his entire foot(size 14)on the pedal and locked 'em and slid into a tree.He said they locked up,yeah I said,when you push hard on the pedal they tend to do that.No ABS here

Great truck,still miss it

Bummer Gramps. Had a buddy with a 77 3/4 ton too back in the day. At that time I was driving my 64 GMC 3/4 ton with manual brakes. I'd drive his truck to back the boat down the ramp to launch, he'd take off on the boat and I'd go park the truck. Geez, talk about touchy brakes after driving the 64 GMC, I'd about put myself thru the windshield just parking the truck. Situations like yours there, goes to show driving experience matters. When I bought my 16 yo old daughter her first car, I made sure it was at least new enough for a driver side air bag, antilock brakes, and traction control.