• Multifuel Hydraulic Head O-Ring Kit


    This is a three o-ring set to replace the old leaking o rings on your multifuel.  I have used these o-rings in countless trucks.  They are good from -65 to 400* and have been proven to last for years of trouble free miles.

    How do you know when you need to replace the o-rings?  If you check the oil on your truck and it keeps climbing then chances are you need to replace your o-rings.

    How to replace?  Take off the side cover that the fuel shut off cable goes into just below the hydraulic head(HH).  When you look in there, a mirror or removing the fender really helps in this task, you are looking for either a red or scored tooth on the gear at the bottom of the HH.  That tooth needs to line up with the small pointer just to the outside of the gear.  Some people have had better luck bumping the starter real slow to get it to line up, others use a pry bar in the jack shaft between the transmission and transfer case.  No matter how you turn it over so it real slow and make sure the fuel is off and disconnected to your injection pump.  Once the tooth is lined up remove the injector lines taking care to place them gently somewhere safe.  Then remove the four nuts that surround the HH.  A few wiggles and the HH should pop right out.  If the tooth is not lined up the HH will not come out so please do not pry on it with a pry bar.  Take special care once the HH is out to not turn it, this will put it out of time and it will not go back in.  The HH can only come out and go in that one position.

    Simply remove the two large o-rings and replace them.  The small o ring that goes on the fuel shut off is where special attention needs to be taken.  There is a bar with two screws that were safety wired in place that that tighten everything up.  DO NOT TIGHTEN these screws when reassembling.  If you tighten them down when you start the motor it either will not run or will rev up and not slow down.  Simply tighten these screws 1/4 turn at a time making sure the shutoff lever can still move freely, when you start to feel resistance it's time to stop.  This is a common mistake almost everyone makes their first time.

    Related Products:

    Hydraulic Head Button

    Retainer Clip

    Hydraulic Head Button Clip

    MultiFuel Spin-On Fuel Filter Conversion Kit

    What's in the box?

    • Three o-rings of different sizes

    Multifuel Injection Pump Videos: