This may be of interest to those who may be thinking of doing this conversion.
Last year I converted my rear brakes over to the 1 ton version. I installed the 1-1/16" dia. cylinders and the 3" wide shoes. At the time I thought they were terrific, although I could easily activate the ABS if I wasn't careful. Since I only used the truck to tow my 5th wheel, and I couldn't lock the wheels when towing, I didn't really care. Since then, after experiencing problems with my transmission, I finally bought an 05 for towing and started to use my 1st gen for general use.

However, over the last couple of months, I have been having problems. Every morning, the first application of my brakes would lock the drivers side rear brake, leaving black streaks on my drive. Further use would find a very aggressive brake until it got warm, and then everything would work OK. This week-end, I got fed up with it, and stripped the brakes down finding the following

Both shoes on the drivers side were badly cracked down the center. The passengers side were nowhere near as bad, but were starting to crack. I took them down to my local friendly mechanic and asked him what he thought might be causing this. He said it was due to heat and towing heavy, but knowing that he knew how I drove the truck, I don't necessarily buy into this, because I have been **** retentive about measuring brake and bearing temperatures while towing, and have never seen high temperatures. And there was no other visble evidence of heat on the drums or shoes.

Does anyone out there have any ideas on what might have caused this?

One further thought, I replaced the shoes with the original 2-1/2" wide 3/4 ton shoes and now find the brakes much better than ever (I still kept the 1-1/16" dia. cylinders). They are not as aggressive as before, but are still much better than the original. If anyone else is thinking of upgrading their brakes, I'd recommend doing the cylinders first, and then only do the shoes if they're not satisfied.

John

 

I had cracking brakes shoes also, but it was my fault. I used the emergency brakes to stop the truck several times. The excess heat cook them good and caused the shoes and drums to crack. I replaced the shoes and turned the drums and all is fine.

I think your problem too was heat and the narrower shoes will help. Don't tighten them up as much either.

 

I've got the 3 inch shoes, and 1 1/16 cyl on my truck and it works fine. I thought I might have a problem when empty but they have never locked up and the abs has never activated. From the looks of that shoe it looks like it was making uneven contact which would cause overheating and and cracking. My guess is for a bad brake shoe.

 

I too think you got bad shoes. What brand were they?

 

Just going by the one pic I`d say defective shoes. The pic doesn`t show too much detail but if the shoes had overheated usually (as has beeen my experience) you will see discoloration of the steel backing the material is bonded to. Also depending on the type/brand shoe if they get hot enough it will start to break down the resins that the friction material is made of, when this happens the surface of the shoe will usually get a "fuzzy" type of appearance...and boy will they howl/squeel. How did the drums look? any blueing/leopard spotting of the friction surface?

 

I bought the shoes from NAPA, who I thought usually sold reasonable quality gear.
No, there was no discoloration anywhere in the brake assembly or the drums. Whenever I've had a problem before with overheating, the linings have been glazed, and the shoes have been blued, or the surface of the drums have shown bluing or polishing, but this time everything looked fine. I examined the shoes and linings very closely, and except for the shoe material being cracked everything looked OK.

Going back and looking again, after seeing DJs comment, I think the shoe material is lifting slightly from the surface of the shoe, which is giving the uneven contact, and possibly causing the lock up on first use.

John

 

Have you taken the shoes back to NAPA? They can turn them in as a defective part and possible find out what happened. Were the drums resurfaced or new? If you put the wider shoes in old uneven drums it may have contributed to their early failure. The reason I am curious, that looks scary.

 

boatnik hit what i was gonna ask... i know it seems like a dumb question... but did you turn the drums when you went from 2.5 to 3 inch shoes?

 

Yes I turned the drums when I went to the 3" wide shoes. It has been a year since I put the new brakes in, but that was only about 5,000 road miles. That is not a lot of miles before they gave me problems.

That's a good idea about turning them back in to NAPA, I'll see if I can find the original receipt. If nothing else, they can throw them in the trash for me.

John

 

I deal with NAPA all the time. In fact I found it to be very advantageous to open an account. Not only do they send a bill once a month but they have a computer record of every purchase that I make so I don't worry about keeping receipts. This has saved my bacon several times replaceing burned out altenators on my old Fords.
I just reexamined the photo. I see very little wear on the shoe. It looks as if the backing was flexing causing material failure.

 

You're thinking maybe the surface of the metal shoe is not contoured to the shape of the drum, and so it flexes when you put pressure on the shoe? Never thought of that!

John

 

In the "old" days, when you had a brake job done, if they turned the drums they "also" bent the NEW shoes to fit the newly turned drums! I guess no one does that these days???

Robert

 

I wasn't aware that stopping with the emergency brake was any big problem... I guess that it puts all the load on the backs, but is it really that big of a deal?

From about what speed does stopping an unloaded truck with your emergency brake become dangerous?

I always figured that if you had the brakes fully locked up that meant that the drums weren't taking any heat at all...

 

So, um, I'm somewhat serious here...

Ya'll are telling me that you can tear out your brake drums going from 30 to 0 with an emergency brake?

Are disks equally susceptible?

 

I've never heard of anyone bending the shoes but they used to re-arc the shoes with a grinder (basically just reshaping the mineral material). Back before the EPA started throwing a fit. A couple of years ago I had some shows that wouldn't seat quite right and my buddy that owns a shop re-arced them for me but he gave me the old wink and a nod. They aren't allowed to do that anymore legally.