1979/04/04 Caterpillar

3406 Industrial Engines;
D348, D349, D353, D379, D398, D399 Industrial and Marine Engines;
D348, D349 Truck Engines.

Description of Change: Several improvements have been made to fuel priming pumps used on the above models.

... A new cap is used in the end of the barrel assembly. The new cap is made of aluminum instead of plastic for increased strength and longer service life.

... The new cap has an improved design of the ramp (slope) for the rod lock pin, which will prevent broken rods or knobs. Formerly, it was possible for the rod or knob to be broken if the lock pin became caught (held) in the lock ramp of the cap.

... A different lock pin is used in the rod assembly. The new pin fits the new lock ramp on the cap.

... A different method is now used to fasten the cap in the end of the barrel. With the new cap, the end of the barrel is peened (bent) into a groove in the cap to hold the cap in place. Formerly, the cap was fastened in the barrel with rivets which loosened from vibration in some conditions.

Adaptable As: Direct replacement. The part numbers of the fuel priming pump assemblies are not changed. Identification of later pump assemblies can be made by the aluminum cap in the top of the barrel. The former cap was plastic.