I have a 2008 GMC Sierra 1500 133,380 miles no check engine light on. Replaced the rear brakes (drum brakes) and is making a squeal sound. I put oem brake shoes, oem drums, new springs, and new wheel cylinders. I bleed the wheel cylinders and put the brakes right and I also adjusted them. I don’t know why it’s making that sound.
Below is the link to the video of the squealing drum brakes
how long has it been making noise? The brakes could still be bedding in.
It could just be buildup of brake dust. If the sound continues, try blasting everything with brake cleaner.
@mountainmanjoe I just replaced them today. As soon as i installed them i went for a test drive and it was NOT making that sound at first, but then it start making it. What is bedding the brakes in mean?
well you've got brand new virgin pads and drums. They've never touched before. It takes some time for the two surface to bed together lol. After they wear down a bit, they will mate perfectly.
Seriously though, your brakes don't work just thanks to friction. They also employ adhesion. Believe it or not, some of the pad material transfers to the drum (or rotor) under high heat. This creates a "stickiness" between the two surfaces which helps with braking. When the the drum (or rotor) is new, it's just naked metal.
In fact, I hear that after a race, cars will sometimes end up with rotors that thicker than they started, because all the pad material ended up on them.