Detroit Diesel: Removal of the Diesel Exhaust Fluid Pump Module

Servicing the DEF pump will almost guarantee you encounter the fluid pump module. This short guide will help you remove it safely.

Remove as follows:

NOTICE: Wait at least five minutes after shutting down the engine to disconnect the Diesel Exhaust Fluid (DEF) lines. Complete purging of the DEF lines requires approximately five minutes after the engine is shut down.

1. Shut off engine and apply the parking brake, chock the wheels, and perform any other applicable safety steps.
2. Disconnect the batteries.
3. Remove the screws and then remove the DEF metering unit cover.
4. Disconnect the six electrical harness connectors from the Diesel Exhaust Fluid (DEF) metering unit.
5. Disconnect the compressed air line connection from the “quick-connect” connector on the DEF metering unit.
6. Disconnect the DEF feed line connection from the DEF metering unit.
7. Disconnect the DEF nozzle supply hose from the DEF metering unit.
8. Remove the three bolts securing the DEF metering unit to the mounting plate.