I parked on hill today, put it in neutral, engaged the emergency brake, then let off the brake pedal, and the blazer started rolling backwards. My regular brakes work, but I don't know whats going on with the E-brake.
Has anybody encountered this problem before? Any Advice?

 

Did you try a search? There are a few people that have encountered it.

Does the pedal stay down or pop back up?

 

I tried a search but I don't think I found the same problem. The pedal stays down but the brake is either weak or not working at all, beacuse I've only had this problem twice when i parked on a snowy hill.

 

There are several issues that can cause this. If the pedal doesnt stay up then you need to replace the pedal assembly under the dash. It is not a hard job at all. The reason your regular brakes work fine is because these are two completely independent braking mechanisms. The shoes in the rear disc hats may be worn, the friction surfaces may be badly rusted, the cable may be completely out of adjustment, the cable housing fixation points may be rusted out. The list goes on. Is there resistance when you push the pedal down or can you send it to the floor pretty easily?

 

There is resistance. It feels the same as the blazer that my dad drives. It just doesn't work.

 

Well if it doesnt go to the floor that is a good sign that you dont have to muck with the rusted adjuster or cable mounts at least. I am assuming that you do not have the problem with the return catch in the pedal assembly. So that pretty much leaves the ebrake friction surfaces. That is in the inside of the rear brake disc hats (used as a drum for the e-brake) and the e-brake shoes. You have to take the rear wheels off, the rear brake calipers off, the rear drums off and there it is. These can be a real pain to adjust and replace depending on what tools you have available and how strong you are. It is pretty obvious how it goes together once you get a look at it. If there is any material left on the shoes, you can rotate the adjuster (if it isnt frozen) with a flat head screwdriver and a few sacrifices to the knuckle gods. There may be a rust/wear lip on the inside of the brake hat that will prevent re-assembly once the adjusters are tightened up. This lip may also make disassembly more difficult. I always grind a chamfer on the inside of the disc hat edge to make it easier every time I take it apart. This removes the lip and sets the material level back from the friction surface so that even if rust builds up, I can still get it apart. My shoes have almost no material left, but they are original. I have adjusted them maybe 4 times in 240K miles. They still hold the vehicle just fine.

Good luck,
-William