VALVE GP-FLOW CONTROL 2120732 - Caterpillar

If air enters the fuel system, it must be removed before the engine can start. Air enters the fuel system if: * the fuel tank is drained during normal operation* the fuel injection lines are disconnected* the fuel system leaks during engine operation* the fuel filter is removed/replacedUse the procedure that is below to eliminate air from the fuel system.
(1) Bolt (on the top of the fuel filter base).1. Loosen the bolt (1) that is on top of the fuel filter base. If a vent plug is installed, loosen the vent plug.
(2) Fuel priming lever. If the drive cam of the fuel lift pump is at the point of maximum lift, the priming lever can not be operated. The crankshaft must be rotated one revolution in order to proceed with step 2.2. Operate the priming lever (2) that is on the fuel lift pump. Operate until fuel that is free from air comes from the bolt (1) that is on top of the fuel filter base.3. Tighten the bolt.
(3) Union nut.4. Loosen the union nut on the fuel inlet line (3). Operate the priming lever on the fuel lift pump until fuel that is free from air comes from the connection. Tighten the union nut.
(4) Fuel injection line fittings.5. Loosen the fittings (4) at two of the fuel injectors..6. Turn the electrical system switch to the ON position. Ensure that the manual stop pushbutton, if equipped, is in the RUN position. Operate the starter motor until fuel that is free from air comes from the fuel injection lines.
Do not overtighten the union nuts on the fuel injection lines. If there is a leak from the union nut, ensure that the fuel line is correctly aligned with the fuel injector inlet. By overtightening the union nuts, a restriction can occur and affect the fuel delivery.
7. Tighten the fittings (4) that are on the fuel injection lines. Torque for the nuts ... 22 N m (16 lb ft)8. Start the engine. If the engine runs for a short time and then stops or runs roughly, check for air in the fuel system. Check for leaks.