Help Please, gun's cylinder drains when I release air from hand pump to disconne

Got a new Bantam Hi-Lite last week, shot a tank through it, shot awesome. My high pressure tank isn't coming until Monday so I've tried to fill it with a hand pump. I get to 200 bar, release the pressure from the pump and the pressure in the pump never drops, the pressure from the tank's gun drops. It's happened twice now and I'm getting frustrated and tired of pumping. I really want to shoot my new gun, please help! Kevin
 
Jarmstrong....You da man!!! I knew it had to be something simple and stupid. I've been shooting for over 40 years, I've been an avid hunter for 35 years, I shoot 1000yd competitions, PRS, skeet and trap and feel like I know a lot! Maybe I do, but I can always learn more, that's for sure! I've been shooting springers forever, got my first Beeman when I was 10yrs. to shoot woodpeckers off all of the neighbor's roof top's to keep them from jamming acorns under the shingles. I got .25 cents per woodpecker and all the shooting made me a lot of money while also making me a great shooter quickly! However, the PCP game is certainly new to my boys and I. Occasionally we get a wake up call like this one...something so simple and easy but we haven't been shooting PCP's long enough to know about it. I tried opening the valve slowly, quickly, medium, etc... Nothing worked. I thought it was the pump but I never had problems with my Hatsan. I started to worry it was my new Brocock...oh snap, not the new Brocock. Anyway, thank you for the quick response, I've been waiting to have a day off to shoot a bunch and measure velocities, accuracy with different pellets and get it 100% dialed it. Again, THANK YOU! Kevin