I keep my 390 oil filter and housing in the parts washer; every few days I will recirculate the fluid through the filter. The fluid outlet connects very easily to the filter using a short rubber hose plugged into the 390 filter housing. I then change the filter every few months when the flow becomes restricted. Parts washer stays clean, fluid lasts a lot longer, and I suspect that the pump will have a longer lifespan, too.
Laniers Speed Shop.
Colorado Springs, CO