I've got a '96 Blazer 2dr 2wd and I've recently been having an issue where the brake pedal will get stuck if it's pushed down far enough. It's my daily driver and most of the time it's a nonissue but every time i have to do an emergency stop, the pedal will be physically stuck down. I've tried to pull it back but it won't budge. The pedal will only release when I stop the engine, and I hear a sucking sound from the brake pedal for a second so I think the problem might be with the booster. When the engine isn't running the brake pedal never sticks.

Also, when I first bought the truck it had a leaking booster so i replaced it with one from the scrap yard. That was 2 years and 20k miles ago. It wasn't an easy job so i'd rather not replace the booster again if i can help it. Does anyone know if there's any adjustment on the pedal or the pushrod thing that goes into the booster? The truck has always had a lot of pedal travel (good brakes though) so i wonder if maybe the pushrod that goes into the booster is reaching the end of it's travel and that's why it's getting stuck? Sorry for the long post but i wanted to include all the details.

 

Not really much adjustment on the rods, sometimes the rod on the peddle has some but not much, In your case sounds like your booster is toast again

If it was mine I wouldn't bother with a scrap yard replacement and put a rebuild in from a parts store or Rockauto, a lot of them have a life time warranty included.

And I know it's your daily but with all things with iffy brakes it needs to be parked it until fixed

 

Solved the problem. I noticed that the master cylinder reservoir was filled up all the way to the top. I guess I added too much brake fluid at some point. I used a turkey baster to suck the fluid down to the MAX mark on the reservoir and now the brakes are working awesome.