Are you soaking your air spray gun in solvent to keep it clean? If you are, you are ruining your gun. Soaking your gun will destroy the packings. It will also introduce solvent into the air passages where it is not intended. The only areas that should be cleaned with solvent are the exterior surfaces of the gun, the fluid passages, aircap, needle, and fluid nozzle.
If you want to soak your gun in solvent, you should also invest in a packing kit. You’re going to need it….