PULLEY-FAN DRIVE 7C1390 - Caterpillar

If air enters the fuel system, the air must be purged before the engine can be started. Air can enter the fuel system when the following events occur:
The fuel tank is empty or the tank has been partially drained during normal operation.
The low-pressure fuel lines are disconnected.
A leak exists in the low-pressure fuel system during engine operation.
The fuel filter or the fuel pump is replaced.
The high-pressure fuel lines are disconnected.Use the following procedure in order to remove air from the fuel system:
Turn the keyswitch to the START position for one second to initiate the fuel pump priming process. Return the keyswitch to the ON position and listen for the fuel priming pump actuation. Leave the keyswitch in the ON position for 3 minutes. If a manual purging screw is installed, the purging screw should be slackened during priming the fuel system.
Illustration 1 g01003929
Typical example
Crank the engine with the throttle lever in the CLOSED position until the engine starts.Note: If necessary, loosen the union nuts (1) on the fuel injection lines at the connection with the fuel injector until fuel is evident. Stop cranking the engine. Tighten the union nuts (1) to a torque of 30 N m (22 lb ft).
Start the engine and run the engine at idle for 1 minute.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Cycle the throttle lever from the low idle position to the high idle position three times. The cycle time for the throttle lever is one second to 6 seconds for one complete cycle.Note: In order to purge air from the fuel injection pump on engines with a fixed throttle, the engine should be run at full load for 30 seconds. The load should then be decreased until the engine is at high idle. The procedure should be repeated three times. The procedure will assist in removing trapped air from the fuel injection pump.
Check for leaks in the fuel system.Alternative Fuel System Prime Procedure
Ensure that the correct fuel priming procedure is carried out. Failure to carry out the correct procedure may result in damage to the fuel injection pump and other fuel system components.
To purge air from the fuel system, there is a new alternative fuel priming procedure. The following procedure should be carried out before the engine is started.
Turn the keyswitch to the RUN position. Leave the keyswitch in the RUN position for 3 minutes.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Crank the engine with the throttle lever in the CLOSED position until the engine starts.Note: If necessary, loosen the union nuts on the fuel injection lines at the connection with the fuel injector until fuel is evident. Stop cranking the engine. Tighten the union nuts to a torque of 30 N m (22 lb ft).
Once the engine has started, operate the engine at low idle for 1