MAINTENANCE 6. After replacing the fuel filter cartridge, run the engine at idle for a few minutes. Check for leaks and repair as necessary. 7. Close the engine hood. NOTE: Controlled venting is provided at the injection pump through the fuel drain manifold. Small amounts of air introduced by changing the filters or injection pump supply line will be vented automatically, if the fuel filter is changed in accordance with the instructions. Manual bleeding will be required if: The fuel filter is not filled prior to installation. The injection pump is replaced. High pressure fuel lines are replaced. 3-55 WA320-3MC