Filter_Base_Ports_1

Oil comes from the oil pump through the port at the right. (Outside of the filter) In our motorhomes with oil cooler, this port will feed out to the cooler via the adaptor. The port in the center comes from the oil filter center port and then feeds the engine. The far left port is the filter-cooler pressure differential valve. If the pressure difference is too high, (plugged filter) it will open and allow the oil to pass into the engine unfiltered. (Better to have some unfiltered oil than no oil!!!)