Usage:
3208 Engines
The fuel pressure relief valve (4N1767 Fuel Bypass Valve) is shown in an inverted (wrong end up) position in some illustrations of governor and fuel injection pump groups in Parts Books for 3208 Engines. This has caused some wrong installations of the valve, when the illustration was used as a reference for assembly.
While wrong installation of the valve increases the fuel pressure approximately 20 to 35 kPa (3 to 5 psi), it is not expected to cause any problems in engine operation or performance, but it does have a minimum effect on modulation of fuel pressure.
To install the 4N1767 Fuel Bypass Valve correctly, put the end with four flutes (grooves) down in the housing. The top end has a round, cylinder-shape that fits inside the spring. In this position, the flutes on the bottom end of the valve give good modulation of fuel pressure.