VALVE GP-BYPASS 1U2043 - Caterpillar

All 3500 Series EnginesThe priming pump is now an attachment for all 3500 Series Engines. If the engine runs out of fuel or the fuel injectors have been removed, the fuel system must be primed (filled with fuel again) before restarting. The transfer pump will not prime the system adequately during cranking of the engine.
On engines with no priming pump, prime the system by pouring clean, water-free fuel into the filter housing. To do this, remove the plug on top of the mounting block for the priming pump.
Only one to two liters (quarts) will initially fill the filter housing because the fuel has to seep through the filters. As fuel gradually seeps through the filter and out to the manifold and injector lines, more can be added. When the system is full, reinstall the plug and crank the engine. It should start normally.