My brother and i were trying to get is old autococker working today and we ran into a problem. The gun when air is added, leaks out of the barrel hardcore. The gun doesn't even cock or cycle. Doesn't seen to hold air at all. Were is a good spot to start looking? The front block doesn't appear to be leaking any place.
You'll want to pull the guts out of the reg and rebuild it by replacing all the orings and lubing them up.
Pull the valve out, and inspect the orings, they're probably non existent or cracked and useless. You'll also want to inspect the cup seal for dents, cracks, or little nicks that will let air pass through.