91 Suburban rear brake drag...

[BenjaminD]

Being that the 91 Suburban is a square body I posted here in hopes of getting some help.

 

I have a 4x4 suburban 1/2 ton I just overhauled the brakes. On the back brakes I replaced everything (All springs, axle brake lines, wheel cylinder, all new hardware including self adjustment wheel and kit and the wheel cylinder links) except the drums and the backing plate which I couldn't find a new replacement. 

 

Please note also there is no parking brake cable at all, no parking brake strut or the arm that holds the cable.

 

Three things I have done that could have contributed to the problem that I want to mention. 

1.) The only replacement wheel cylinder links I could find were slightly longer. (The original ones were terribly rusted and there was no drag what so ever.)

2.) I cheaped out and didn't get the rotors turned. They looked fine.

3.) The backing plate tabs had grooves in them so I carefully ground them nearly flat as to not take an insane amount of material off.

 

So I put everything together and adjusted the star wheel to where the pads were just barely touching the drums. With the wheel off, the drum did spin nice and freely. Though I suspect slight warpage.

 

I drove to town about 7 miles away and back and everything seemed normal. Got out of the truck and smelled a burning smell and noticed the hub on the driver's side rear wheel was too hot to touch. 

 

I jacked the truck up and the wheel could spin freely by hand going backwards, but forward it would lock up! 

 

I took the tire and drum off and backed off the adjustment some, put it back together and once again it moved forward and backwards freely. Took it for another test drive and the same thing.

 

I have ordered another set of pads because the ones I put on are heat damaged and ordered a new set of drums.

 

I just can't figure out why they would lock up going forward and not in reverse. 

 

I'm just fishing for ideas here, never seen anything like it.

(Update): I lightly sanded the brake shoes and they look good as new. I got the rear end jacked up and backed the star wheels all the way to the closed position. 

 

With the drum off on the driver's side, I lightly pressed on the brake and the rear shoe was failing to return to a closed position. I added extra lube and it appears to be functioning. But I still  don't feel confident the problem won't return.

 

Anyhow,  I'm incrementally adjusting the star wheel by 50 clicks on each side and with the truck in neutral the wheels turn and I work the brakes. Put it in drive and reverse working the brakes. So far so good. Now making smaller increments in adjustments.

 

If anyone knows where I can find brand new backing plates and the proper wheel cylinder links it would be much appreciated. I can't find them. I even called Dorman and they have nothing. It's a 91 ten bolt, 30 spline, 6 lug axle.

 

I found a disc brake kit for around 400 bucks, but I feared having to change out the proportioning valve and master cylinder. I don't know that I would,  but am afraid to open that can of worms. Unless someone has did a rear disc conversion and can tell me otherwise. 

 

I'm just wanting my brakes to work properly. It's a rusty old truck that's my daily driver.

Edited May 8, 2020 by BenjaminD