Puzzling Brake Problem

brakes
chevrolet
colorado

#1

My truck pulses forward and backward when I brake. It doesn’t always happen. It seems to do it more often after I have been driving for a while. I also hear some squeaking from my rear driver-side wheel sometimes when I brake.



I did a brake job on the rear brakes (replaced shoes and had the drums machined) about 15,000 mi ago. I did a brake job on the front about 5,000 mi ago (replaced both rotors and pads). I looked at the rear brakes recently, but didn’t see anything that looked unusual.



What should I look for? I would like to do these repairs myself.


#2

The best guess I have is intermittent sticking calipers. The rear calipers are most often suspect.


#3

Drums can warp, and having them turned may have removed too much material to enable them to handle the heat.

Try jacking up each corner of the car and spinning the wheel by hand while a friend slowly applys the brakes. You’ll feel the pulsing resistance on the corner that’s causing the problem. Then you’ll know which end needs work.

By the way, when you replaced the pads and rotors, did you clean the rotors with brake cleaner or a solvent before installing them? You may have residue from the protective coating the manufacturer shipped them with.