brake problem
 

I've had the left rear wheel locking up for a while and haven't driven the truck. Today I had time to mess with it. After pulling the wheel and the drum, I found 2 problems. 1st, the spring over the adjuster between the brake shoes was broken. 2nd, I had a right-side adjuster on the left side. So I dug thru my parts stash & found some new parts. After I got everything back together I took it for a short drive. No wheel lock up so far, but tomorrow I will put some miles on the truck. Wish me luck.

So today I put about 60 miles on the truck. No brake problems. They just need to be adjusted.
Hopefully the problem is solved.

Re: brake problem
 

I'm sure you are aware but, for drum brakes make sure to loosen off the park brake adjuster before adjusting the service brakes. readjust it after the service brakes are set up.

Re: brake problem
 

Thanks for the reminder.

Re: brake problem
 

Self adjusting brakes ( a misnomer unless you back up and hit the brakes a lot) or old school get under it and adjust them brakes.

I was taught to in 1962 and have done the same thing thousands of times To tighten the adjuster so you can't rotate the wheel and back it off 11 clicks. Yes you will have some drag but that is required.

Re: brake problem
 

I'd take GM rear drum over rear disk any day. The self adjusters work well if they are setup properly and the parking brakes work.

those back it off x clicks guidelines are not accurate in my opinion

back 80s I did brakes professionally for a guy that owned his own independent brake shop for 40 years, here is how he taught me, it has served me well:

Make sure the springs and other hardware are in good shape
make sure the drum is in good shape with no ridge of rust at the edge (we'd turn them on the lathe every time anyway for a perfect surface.)

scrub each shoe back and forth inside the drum it is intended for, you want a close radius match with contact spots in the center of shoe, if the contact points are at the ends and not the center the brakes will grab hard and probably cook the material. (we'd arc each pair of shoes specifically for their drum on a shoe arcing drum sander. A shop vac is all you need to control the dust right? or so the safety standards of the day said :( )

Clean and never seize the shoe pivots and contact pads, the ebrake pivots and the pivot for the self adjuster arm. make sure the shoes can slide across the backing plate contact pads without hanging up.
take the adjuster apart, clean it well, make sure the star wheel has not been chewed up by misguided tools, lubricate adjuster threads and both ends with a combination of never seize and motor oil....it should turn buttery smooth

Assemble the shoes, springs and adjusters, make sure you do it right and do not trust the last guy or random pictures online. maybe find a picture in an old manual for guidance. take the time to understand how the adjuster works....when the brakes go on in reverse or with ebrake and the rear shoe lifts off the fixed top anchor point that rod from the anchor pulls on the adjuster arm. When you understand how it works you will know which adjuster goes on which side and how using the park brake or stopping in reverse adjusts the brakes

turn the adjuster wheel with your fingers, make sure you get a good ratcheting action from the adjuster arm.

slap the shoes back and forth across the backing plate a bit with your palms to center things up. Slide on the brake drum, make sure there is no drag(1), take it off and spin the adjuster a bit, repeat the trial and error adjusting with drum on and off until the drum has a light drag. We'd never use the adjusting slot here, too slow. When you get a light drag, leave the drum on.

blead the brakes.
Stomp the service brake and parking brake a few times to center things up, do one more check for light drag at the drums, adjust if needed.

Mount the wheels & one last check that there is still light drag (2) adjust a click or two through the slot if you need to, go for test drive. Ease the brakes on when you stop, windows down to listen for any untoward noises. A few gentle stops, then test the park brake on a slight incline, make sure it holds. couple more stops including bringing speed down from about 40 mph to 10 a couple times with moderate braking to make sure it stops straight.

hand the car to customer, tell them their brakes will last longer if they can take it easy on them for a few days. Tell them the best way to keep their brakes adjusted is to use the parking brake every day

(1) if you can't get to zero drag at this step chance are someone 'fixed' a low parking brake by cranking up the cables instead of properly servicing their brakes at the wheel. Doing this dramatically shortens the life of the brake job by burning off the upper ends of both shoes. Adjusting the parking brake is only needed if a cable is replaced, otherwise it is set once for the life of the vehicle.
(2) light drag for a new drum brake job with tire bolted on would be giving the wheel a moderate one handed spin and it stops in about 3/4 revolution. This is harder to judge on rear axle especially with positraction.