The rear brakes on my '92 Corsica have locked up twice in two days. Both times the car has sat for 10-12 hours (while I'm at work). When I go to leave the rear brakes lock up and skid on the gravel parking lot. Then, once I'm on the street the brakes are ok. Every time I brake after that, everything is ok. My question is: what can I do to fix it so in case we get more snow (heaven forbid), I'm not sliding to a stop?

 

Move? The snow is packing up, then feezing in the brakes, is the back plate intack?

 

Sorry, I didn't give enough info. Most of the snow has melted here. It's been in the 40s most of the week.

Anyway,
The left rear wheel cylinder was recently replaced due to it leaking. The mechanic said that should take care of the "grabing". I hadn't had any problems with it at that point, so I wasn't quite sure what he was talking about.
I've driven the car to work all this week. It grabs slightly when I back out of the driveway in the morning (rear of car sinks down), and then it's fine. Then when I leave work in the evening, it grabs, causing it to skid on the gravel parking lot (rearend sinking again). Once I'm out on the street, it's fine again.

The mechanic did say that the brake shoes on the left side were soaked in brake fluid. He cleaned them up the best he could and put it back together. Could the shoes still be fouled and lock up after sitting awhile?

 

These should be replaced.

 

Ok. Can the shoes be replaced without bleeding the brakes?

 

Yes, you need to find the cause of the leak, and fix it. That will require bleeding them