Where should an oil filter go?

An oil filter can be mounted on the suction line or pressure line. We recommend mounting on the return line (between valve outlet and reservoir) so you do not restrict your suction line, and so a finer filter can be used. Strainers are often used in the suction line, but they are sometimes forgotten and when sludge builds up around them they block flow to the pump. A pump with a blocked suction line doesn’t last long!