Brake Issue/question

[Bostonian1976]

Hi all- trying to figure out why I have a recurring brake vibration issue.

When I stomp on the brakes, I get a harsh (really harsh to the point that people on the sidewalk stop and turn their heads) grinding sound that occurs with each rotation. In other words it's as if there's a certain part of the drum that grabs with each rotation, shaking the truck and vibrating all of the aluminum to create a scary noise for any passengers or people within a 1 mile radius

Last time I took the wheels off and sanded the inside of the rear drums, which worked.

My question is - why is this problem back again after some non-use?

And - would going to a big parking lot and repeatedly stomping on the brakes smooth it out?

Pads are fine by the way

[LaneRover]

My question is - why is this problem back again after some non-use?

My guess would be rust build up on the brake drums and shoes. You say the pads are fine but have you taken off the drums to have a look?

Brent

[Bostonian1976]

Well last time I had them off the pads were close to 100%. I think I've maybe done 300 miles since then...

[LaneRover]

Sorry I didn't mean are your shoes still good. I meant have you had the drums off to check for rust or anything like that? If 'sanding' took care of the problem last time maybe rust has 'grown' back and is causing the grabbing again?

[Bostonian1976]

Yeah I guess that's what occurred. I'm just curious why it keeps happening in the rear drum? Do you guys get this after periods
of non-use?

[LaneRover]

Something that is misaligned? Or as mentioned in the other brake post studs that are the wrong length and are so close that a tiny difference in clearances makes all the difference?