I need to know if you have one of the smaller, new style pumps or the older, tall style. The cause of gas leakage through the terminals in either case is a faulty seal. In the case of the smaller pump, it is one of the small o-rings behind the red/brown plastic terminal strip. The stock o-ring has a square cross section but you should be able to successfully seal it with round cross section o-ring of suitable size and some gas resistant Seal-All if you can't find a sq cross section ring. If you have the tall style pump, you will need to disassemble the pump and do some work on the main bellows seal since you have gas seeping by the seal into the motor section. The new style pump is designed to operate with fuel in the motor can, the old style is not. Hope this helps.
George