Usage:
3176 (2YG) Truck Engines
Description of Change: A new fuel transfer pump group is used that has a new cover assembly. The check valve in the cover assembly is now located on the pressure side. This permits system pressure to assist in keeping the valve seated in the cover. See Illustration 1. In the former cover assembly the check valve was located on the suction side of the pump. The check valve in the former design was susceptible to loosening. See Illustration 2.
Adaptable To: The new 4P1838 Pump Group is a direct replacement for the former 9Y3347 and 7E2905 Pump Groups (both canceled). The new 4P0989 Cover Assembly, which contains the 2W2534 Valve Assembly, is a direct replacement for the former cover Assembly and is adaptable to engines using either of the former pump groups.
Illustration 1. New cover assembly. (1) Valve assembly. (2) Cover.
Illustration 2. Former cover assembly. (3) Valve assembly. (4) cover.