The speedaire units are made by Champion. You can use Champion replacement parts cheaper than buying at Grainger. That looks like a single stage twin cylinder unit. Therefore cooler operating temps, lower working pressure up to 135psi. Ad says not holding pressure! If the tank leaks, it is a time bomb. Otherwise if it is leaking back out of the unloader valve (tube fitting on the front of the pump), then it is a dirty check valve at the tank. Leaking tanks are dangerous, and new replacement tanks cost more than the compressor is worth. That Baldor motor new goes for about $400 right now. Champion pumps and Baldor motors are good stuff!