hey guys whats up i have a 450c vi air compressor filling up a 5 gallon tank. but the compressor turns on and it runs, but the tank doesnt fill. i checked all the lines and fittings and there is no "hiss sound" no leaks. what can it be.it filled the tank but with no pressure i let go of an airline from the tank and air comes out but for like 1 second and then theres no more. n ive left the compressor running for a good 5 minutes. what can it be? check valve?