The Fleece SureFlo Sending Unit is designed for 2011–2016 Duramax LML long bed trucks. It provides a clean solution for running aftermarket lift pumps without drilling the fuel tank. Instead of using a draw straw or sump, the Fleece SureFlo Sending Unit installs directly into the factory sending unit location. As a result, installation is simpler and the fuel system remains reliable.

Many aftermarket fuel setups require modifying the fuel tank. However, these setups often create the well-known ¼ tank issue, where the pump begins drawing air instead of fuel. Because the Fleece SureFlo Sending Unit pulls fuel directly from the bucket assembly, the pump stays supplied with fuel even at lower tank levels.

In addition, the system returns fuel directly to the bucket assembly at the base of the unit. This design helps maintain consistent fuel supply and reduces the chance of cavitation. As a result, aftermarket lift pumps can operate more efficiently and reliably.

If you are upgrading the fuel system on your truck, be sure to explore our selection of Duramax diesel performance parts for additional upgrades designed specifically for Duramax powered trucks.

Fleece SureFlo Sending Unit Features

OEM style fitment that requires no tank cutting or drilling
Heavy duty billet aluminum cap for durability
Factory style quick disconnect fittings for stock fuel lines
Universal –8 AN ports for custom fuel plumbing
New fuel level electronics and float assembly
New O-ring or flange seal for proper installation

Cross Reference

Direct replacement for the following fuel sending units:

GM 19257326
AC Delco MU1976
GM 13578388
AC Delco M100021

Application Notes

For Titan fuel tanks, reference the Fleece Performance fitment data before installation. However, this sending unit will not fit S&B fuel tanks.

For best results, this unit has been tested with aftermarket lift pumps including:

AirDog II-5G lift pumps with flow rates up to 220 GPH
FASS lift pumps with flow rates up to 100 GPH

Warranty

1 Year Limited Parts Warranty

1 Year Limited Parts Warranty

If you’re working on upgrading the fuel system on your truck, be sure to explore our full selection of Duramax diesel performance parts to find additional fuel system upgrades designed specifically for Duramax-powered trucks.