I have a 2010 GMC Canyon. When you first start up and put the vehicle in gear the breaks will not release.if you accelerate then it will pop and release. This will happen the first two or three times you start but gets better as the vehicle warms up. I also noticed that it started happening when it got colder outside. this week it has warmed up to 73 and it had all but stopped. As soon as it got cold again it started back. I have ordered new cylinders for the rear and am planning to put them on this weekend. Not sure if it will help but it sounds like they are sticking out maybe. Anyone have any ideas before I try that?
It may be that your brake shoes are too close to the contact area. Does your handbrake click at least 4 times before it grips tight? If not, then you can adjust the shoes to allow more clicks on the handbrake. Metal contracts slightly when it's cold, so this may in fact be the case.
Another thing that usually happens is that the mechanism within the brakes rusts. I've had great success spraying mine with brake cleaner, then WD40 and finally applying some grease to the moving parts (obviously not ON the actual contact areas). You may want to have a look at how the handbrake cable operates the rear brakes and make sure they release properly. Again, some brake cleaner, WD40 and grease will help.
The rear brake adjusment on most vehicles includes a bi-metal, heat sensitive arrangement which prevents the brakes being adjusted once they become hot operationally. You need to make sure this arrangement on your vehicle is working properly. The way it works is that when the brakes are cold the brakes are able to adjust up. When the brakes are hot, the drum expands to a greater diameter which would allow the brakes to over adjust whilst hot. The bi-metal arrangement will prevent over adjustment whilst the brakes are hot. If the bi-metal is not working, the brakes will over adjust whilst hot and when the brake drums cool and contract they will bind onto the shoes.