• M939 Dual Fuel Line Kit


    Please note the new version of this kit still uses your existing fuel shut off valve.  If you need to replace yours and want the original version of the kit(pictured) please let me know so I can ship it as such.

    For those of you with the M939 and M939A1 trucks with the Cummins 250 this kits is a must.  By adding this kit you will balance out the fuel flow to your common rail fuel system by feeding both the front and back heads the same temperature and pressure of fuel.  Your truck with have improved throttle response and even an increase in horse power.  This kit can be installed in a few hours over the weekend.  I found it easiest to remove the dog house in my cab for full access to the back head.  However, some have suggested cutting in an access panel into the dog house for the same level of access and no need to remove the dog house.

    Things to note with this kit:

    • You should add an EGT gauge to your truck because you are adding more fuel to the system.
    • Your emergency shut off cable will not work with the new shut off valve.  There is a shut off valve in this kit but it is a different type than stock and doesn't work with the cable.

    Product Video

    What's in the box?

    • Two new high pressure fuel supply lines
    • Three labeled bags with fittings for the front head, back head and injection pump