I recently got the CrankBros Power Pump alloy and am loving its high pressure switch. The problem is, the built-in gauge doesn't seem to work. The arm on the dial would go up, as expected, when I'm pumping. When I reach my desired pressure [as shown by the arm in the gauge] and stop pumping, the arm would slowly go back down to zero while the pump is still attached to the valve. I'm not detecting any leakage in the pump head-valve connection [I could be wrong], so what could be the problem? Is there something wrong with my pump? Is it just the gauge?