Car is a 93 Z28 M6. I park in the driveway, which has a decent slope to it. Got home, killed the engine, engaged the parking brake firmly as usual, and a second later it made a loud BANG as it slammed down into the disengaged position. Still had my foot on the brake thankfully. Reengaged it several times and it seems to be fine -- can't recreate the problem. Maybe the button was somehow stuck in a bit, but that would be weird since I don't use that to engage it (I just pull it up).

There are cars parked on the street behind my Camaro and if the brake failed it would cause major damage (I don't trust 1st gear alone to hold it if something failed). Anyone had this problem or know what I should check?

 

Mine does that too - been that way for 15+ years.... Just re-engage when it happens. I'm guessing it's a spring load of some sort - and the spring pops back with too much tension - as it seems to happen when I pull all the way to the top too quickly (Mine will actually engage at 1/2 way - but I still pull it up all the way at times).

Always holds just fine when parked on my steep driveway without issue.