I have a newly rebuilt 235 for my 58. I installed a rebuilt dual action fuel pump in April and it began to leak at the lower flange last month. I tightened the screws but it continued. Concerned that it may be leaking inside, I replaced the pump with another from a vender and changed the oil. The new pump has started to leak at the lower flange as well. Any ideas what may be causing this? It is not dripping but the gasket and area around the screws is wet. Please advise.