MBE 4000 Unit Pump Inspection/Removal
To determine if the unit pump and nozzle is not functioning properly and needs to be replaced, follow this procedure:
- Drain fuel system and remove unit pump. If necessary, remove nozzle.
- Wipe oil off unit pump.
- Inspect unit pump and nozzle for leaks, turned O-rings, seized pump, cracked body, or failed/ blown spray nozzle.
Follow the service manual procedure to remove the unit pump:
- Remove the engine trim cover.
- Unscrew the fuel filter cap.
- Disconnect the engine wiring harness from the injector unit pump.
- Remove the high-pressure fuel injector line.
- Disconnect the fuel line at the fuel gallery inlet. Use suitable container to catch any fuel that comes out of the cylinder block or fuel line.
- Drain the fuel from the engine through the fuel gallery outlet on the return lines.
- Remove the end cover from the lower right side of the flywheel housing, then attach the engine cranking tool (J-46167) .
- Carefully loosen the injector unit pump mounting bolts about 6 mm (0.25 inch), but do not remove them yet.
- Using the cranking tool number (J-46167) , rotate the crankshaft until the cam pushes the unit pump upwards.
- Remove mounting bolts and carefully pull unit out of cylinder block. Discard O-rings.
Note: If the injector unit pump is locked up, or frozen in its seat, release it using the blade of a small screwdriver on the flange where the mounting bolt attaches.
If nozzle and holder needs to be removed, follow this procedure:
Note: Do not attempt to take apart the nozzle. If there is a problem, replace the nozzle.
- Remove the engine trim cover and cylinder head cover for each cylinder head.
- Remove the charge-air manifold.
- Remove the injector line.
- Remove the thrust bolt and the transfer tube. Discard the old O-ring.
- Remove the tensioning arm.
- Attach the impact extractor tool (J-46375) and adaptor tool (J-46384) . Thread the narrow end of the adaptor onto the internal M8 threading in the head of the nozzle. Thread the impact extractor onto the wide end of the adaptor.
- Using the impact extractor tool (J-46375) , remove the nozzle from the cylinder head. Discard the O-ring and seal ring.
- Cap off or cover the openings in the fuel lines to prevent contamination of the fuel.
Note: For current information on removal and installation of unit pump or nozzle, refer to MBE 900 service manual (6SE414) or MBE 4000 service manual (6SE412).
|Unit Fuel Injectors and Unit Pumps Technician's Guide - 7SE500|
|Generated on 10-13-2008|