gauntlet fill issues.

the last few times i have been filling my gauntlet from my 75 cu. ft tank, it will ramp way up on the gauge fast then when i turn the valve down it drops way down. i can hear the click of the foster fitting but its like it is not letting air in. I just ramp it way up and turn the valve off and repeat.....

it will finally fill this way. my wildcat has no issues. so i know it is the Gauntlet. i put a new stainless foster fitting in it several months ago and has worked fin until about the last 5 fills. could it be anything other than the fitting???.
 
They use a very low quality foster fitting. Disassemble it and put a light coat of silicon oil on the piston. This fixed the one I modded for my son.

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