5869-1 J-47912-QC Fuel System Coupler Fitting Quick Connect Fits Detroit Diesel. This fuel system coupler fitting is designed to connect to the hose of ONI581T and assists with fuel system priming by connecting through a “compu-check” quick connect fitting, for Detroit Diesel S60, MBE900, MBE4000, DD13, and DD15 fuel system priming pump.