Very common problem with the CN350 and CN325 nail guns.

I sell kits for these guns on ebay CN350 leaking trigger and here.
Duo-Fast CN350 O-ring + Cylinder Seal CN-220-3
Duo-Fast CN350 O-ring + Cylinder Seal CN-220-3
CN350 O-ring Kit + Cylinder Seal #cn-220-3
Schematic + O-ring Reference Sheet
Available Qty: 9