Hey spunbearing,

I sure used a poor choise of words didn't i??? Sorry about that...

Robert

 

Hey, no problem Robert I just thought that you were talking about another method I've never heard of. Theres lots of stuff I've never heard of. I are a fart smeller umm I meant smart feller.

 

John,

Just to beat this to death -- did you check to make sure that your drums are machined properly? That is, that they are machined flate and square? The problem that you were having was from the driver's side being over-adjusted, probably due to the brake shoes flexing excessively when they were applied. It certainly seems to me that either the shoes were the wrong shape, or the drums were the wrong shape, and that is what caused the problem.

 

No, I was really thinking that all the force applied to the brake is in the mid line of the shoe. I am also thinking that there is an air gap in the same location under the brake friction material. Under hard braking the center segment applies its force right on the air gap which should be full of epoxy, maybe?

 

I haven't found the receipt yet, to take them back, so if I still can't by the weekend, I may as well chisel off the lining and look for evidence of lack of bond.

John

 

I wanted to resurrect this post since I have just reworked my rear brakes. I had planned to go with the 3" shoes but I could not understand how they could fit in a system designed for a 2.5" shoe.

I pulled the drums off and examined them first. My 2.5" shoes were wearing all but about 1/2 an inch of the inside of the drum. They were wearing to the very outer edge. It was the inner edge of the drum nearest the bolt pattern that wasn't wearing. So, with just that in mind I guess the drums could accomodate a 3" shoe.

Next I examined my existing 2.5" shoes. This is what got me thinking about the picture on the first post. The back side of the shoes run up against the backing plate (inboard) so they can't move that direction. What keeps the shoes from moving outboard? I determined it is a combination of springs and the most important part, the post at the very top of the backing plate. We have a large diameter (1") post that both of the brake shoes rest against when inactive. When the wheel cylinder pushes out on the shoes they come away from that post. There is a plate attached to that post that keeps the shoes from moving outboard when the brakes are activated. This system assures that the shoes stay in the same place on the drum each time they are activated.

On my shoes, the part that rests against the post also rests against the plate. If I were to try to put a wider shoe in place, they would sit at an unnatural angle. If I were able to put the drum back on and actually use the brakes it would cause the inboard side of the brake to push on the inboard side of the drum. This would cause the shoe backing to try to bend. Of course it would bend at the center, where the support is.

I noticed the inboard edges of the brake shoe in the picture is burned, cracked and broken. I am sure this is what happened.

If the pin that the brake shoes rest against was a little longer it could accomodate a wider shoe. Mine will not.

I would highly advise anybody who has changed to 3" shoes to check their rear brakes.

I am very interested in hearing back from people that have done this mod.

 

The drums I have seen are stamped either 2.5" or 3.0".

I never heard of trying to run 3" shoes in a 2.5" drum.

Please enlighten me on this.

 

I'm running 3 inch shoes on mine and theres no problems.........well no problems since I put the adjusters on the right way. A friends shop did mine and the tech installed my adjusters with the teeth going the wrong way on the clicker. Dohhhhhhhhhhhh
I had a little bit of a mushy pedal when I first installed the larger wheel cylinders but it turned out to be my master cyl. No problems with the shoes themselves. The 1 ton uses the same shoes and the same drum.