When you leave the temperature on 1250 for smoking do you wet the sawdust, and does one pan last long enough or do you have to refill?

I have the 11 lb. Walton stuffer, and Have had a problem lately where the meat goes past the piston. I’ve put in new gasket, which didn’t help.
Can anyone tell me what the issue could be And what the solution is. Thanks.

PapaSop
Thanks for the reply Papasop. That’s how I have the gasket on. Do you have any other ideas/suggestions?