Bleeding the Fuel System

Parent topic: Engine Fuel System

SG 3500 Series

If the engine runs out of fuel, fuel filters replaced, repairs are made to the fuel system, or air gets into the system for any other reason, air must be bled out of the fuel system to prevent interrupted unit operation or possibly severe damage to the high pressure fuel pump. Never attempt to purge air and prime the high pressure fuel pump by cranking the engine with the starter.

To bleed air from the fuel system:

  1. Reconnect the battery.

  2. Place a proper fuel catch pan under the fuel filter location.

  3. Turn the unit on. Do not allow the engine to start.

  4. When pumping fuel, open the bleed screws on the top of the fuel filter heads.

  5. Air from the fuel system will escape through the open bleed screws. When all the air has escaped, and a constant flow of fuel is existing the open bleed screws:

    • 1 - Tighten the primary fuel filter bleed screw first.

  6. Turn the unit OFF and clean any spilled fuel. Dispose of fuel and filter according to local regulations.

  7. Turn the unit ON and allow the engine to start. Observe the engine run for a few minutes. If the engine fails to start, or starts but stops in a few minutes, repeat the fuel bleeding procedure.