I have a Smith regulator that came with my Miller 252. When the gas is turned on the tank the low pressure gauge slowly keeps rising. If the mig gun is triggered the pressure falls and I hear gas coming out of the gun. When the trigger is let off the low pressure gage continues to rise irrespective to the adjustment on the screw. When the gas is fully bled off the gage stays at 10 and will not return to zero. what is wrong with the gage?