Tap brakes and rear drums start sqealing?

[Chilly178]

I have a 72 C20. Few years ago I replaced just the brake shoes and wheel cylinders in the rear drums, I din't replace any of the springs. Now I'm having an issue when my rear drums are squealing. It started when I would hit the brake and I would hear a small squeal. Now its to the point where I have the rear end jacked up and I put it in first and let the tires slowly spin and its fine, then I tap the brake and then take my foot off the brake and now the drum(s) are sqealing just with the wheels turning. Thinking I'm gonna have to take the inner axles off again, change the fluid, and change all the springs and everything this time. Any ideas before I rip into it? Could this also be a emergency brake issue? I did have a guy adjust my cable for it, maybe too tight?

[Steeveedee]

The shoes could just be glazed. If they're real shiny, just hit them with some 80 grit to take the glaze off and see if that helps. Or, you could be into the rivets. Take it apart and find out. How many miles since it was relined?

[Chilly178]

What do you mean by relined? Is that something with the drums? I wonder if the drums aren't adjusted right, I heard backing up and stopping would adjust them?

[Steeveedee]

Relined = new friction material lining on the shoes, or just new shoes. Back in the day I've actually drilled out the rivets and riveted on new lining. We also had a machine to grind the shoes to fit the drum. That's a big asbestos no-no, these days. Now the shoes are simply ground for the minimum expected diameter- "cam-ground" and then they wear in to the drum.

[special-K]

I wouldn't worry bout changing the fluid unless it's just time for that. Do they seem to drag a bit once they start squealing while lifted? Could be the brake hose is collapsing. Time to take a look, but first put it in neutral and spin buy hand. Then hit the brake pedal and see how it spins.

[mike16]

maybe you should have replaced the hardware as well. if the shoes are glazed , clean them up but maybe turn the drums a bit too

[cleszkie]

Are shoes installed properly. Each side should have a shoe with long and short lining lengths. I can't remember now (I run four wheel disc brakes now), but I think the shoe with the short lining length faces the front of the vehicle on both sides of the truck. If you don't install the shoes this way, the shoes can drag on the drum when the pedal is released.

Yep, the short lining faces front of vehicle.

[Steeveedee]

Originally Posted by cleszkie

Are shoes installed properly. Each side should have a shoe with long and short lining lengths. I can't remember now (I run four wheel disc brakes now), but I think the shoe with the short lining length faces the front of the vehicle on both sides of the truck. If you don't install the shoes this way, the shoes can drag on the drum when the pedal is released.

Yep, the short lining faces front of vehicle.

The front shoe causes the rear shoe to push into the anchor pin at the top of the backing plate. As a result, the rear shoe does more braking, so the front shoe is usually shorter. It depends on the manufacturer, as well. Some sell shoes with the long lining for all four. That's what I got when I did my rear brakes recently. Not sure why they did that, but the ones I took off were the same way. Wrongly installed shoes do not drag, if the springs are good. I've never seen that, and I've seen many a set of mis-installed shoes, as a brake mechanic.