All model VE pumps use a percentage of the fuel delivered to the injection pump housing to cool and lubricate the internal pump components. Since the diesel fuel will pick up some heat through this action, a bleed off or fuel return from the injection pump housing is achieved through the use of a hollow bolt with an orifice drilled into it as shown in Figure 19-74.
This bolt is readily identifiable by the word OUT stamped on the hex head, and if substituted with an ordinary bolt, no fuel will be able to return to the fuel tank from the injection pump.
