Fuel check / overflow valve 7139-854W Delphi DP, aftermarket

Fuel check / overflow valve 7139-854W is an aftermarket part for the diesel engines with Delphi DP210, DP310 and DP200 pumps.

This valve controls the direction of flow or the pressure in the fuel system. A check (non-return) valve lets fuel flow only one way and stops it draining back to the tank when the engine stops, so the system stays full and starting is easier. An overflow (bypass) valve holds the pressure in the pump or filter housing at a set value and sends surplus fuel to the return line, also helping to purge air. A weakened valve spring or dirt on the seat causes the system to drain down, hard starting or low supply pressure. Marking the lines on both sides of the valve before removal removes the risk of fitting the new valve the wrong way round. Always bleed the system after fitting.

Specifications

Compatibility

According to the product card, 7139-854W is a fuel valve. Fit is confirmed by the part number. Other parts are in Sensors and valves.

Fitting

Before the change, stop the engine, let the fuel system cool and clean around the part, capping any fuel connections as soon as they are opened. Fit the new part with new gaskets or O-rings and tighten the connections to the torque in the service manual. After assembly, bleed the fuel system, run the engine and check for leaks and smooth running.