usually its just an oring on the bolt (bolt sail) that can cause a leak by the solenoid...there are a few others, but most common (imo) is the bolt sail.
get him to pay for a new noid, check the bolt sail, and if you are lucky, its just the oring. and you have spare cash...
if you bring it out to pbc, ask for me at the field, i can take a look at it for you.
Raza paintball sucks
GOSPORTS is TERRIBLE TOO