Rear brake drag

[VCaddy]

I can't figure out why the passenger side rear brake drags so bad, bout to smash the whole damn thing with a sledge. Just swapped in my rebuilt 14SF, all new NAPA brake components. Driver side drum is ambient temp after driving, gets to maybe 125 after some brake applications. Passenger side is 300 degrees after cruising. Drum is full of dust. I didn't have this problem with the old 10 bolt brakes.

I've manually adjusted the shoes, the brakes seem to bleed OK, fluid drips out when I back off the bleeder, I ground down the little pads that the shoes ride on, still a slight groove in those though. I put brake grease on all the contact points. The parking brake cables are new, and the lever is retracted all the way.

I just don't get it. Try grinding the pads on the backing plate to a mirror surface? Maybe the brake line is clogged and acts as a check valve? (that doesn't make sense since fluid drips out of the bleeder) Bad wheel cylinder? I thought maybe the drum was grinding on the backing plate somewhere, but there's no polished off spots or hot spots in the backing plate when I shoot it with the temp gun.

 

[90halfton]

Most likely the check valve effect is happening. Has happened to me on my front brakes.

 

[sewlow]

Plugged/collapsed brake line?
Let's enough fluid through under pressure when the brakes are applied, but is restricted enough so as not to let the pressure release when off of the pedal.

 

[VCaddy]

Yeah, maybe I did crush or bend one of the hard lines enough to kink it when I did the whole axle swap. Thought I was careful enough, but you never know with 20 year old lines.

 

[michael hurd]

Possible bent axle flange, too much lateral run out, or the drum face is not perpendicular to the machined surface for the shoes.

Do you have access to a magnetic base dial indicator?

I would want to check the run out on the face to be sure.

Another cause could be failing axle bearing and / or surface degradation on the axle shaft on that side.

Edit - I just re-read where you said it is all new components.

I would still check the axle flange for run out though.

 

[Bob L]

If you have one flex line running to the axle feeding both wheel cylinders and only one is heating I don't think it is the flex hose. Is the line that kinked the side giving trouble? If so it could be taking a while for the brakes to fully release on that side. When applying the brakes you get a lot of pressure to the cylinders but when releasing only spring pressure to return the fluid. A bad check valve should effect both sides also.

 

[Huck Finn]

Had same issue with mine, redone brakes, cylinder, still done it, next week replaced withnew drum, problem fixed, warped drum