New Air Dog Fuel Preporator II Fuel Pump Install

The diesel fuel that I use comes from different truckstops all over the USA and it's hard to know if the fuel you are getting is clean.  This is where the fuel filter comes in.  All vehicles that run fuel have them and with a big rig, the amount of fuel that is flowing through the filter is thousands of gallons per year.

My truck is equipped with a water separator which removes water from the diesel fuel and keeps it out of the engine's fuel injectors.  Water can ruin fuel injectors.  In addition to the factory installed Davco brand water separator fuel filter, I have installed an AirDog II Fuel Preporator.

This device has a water separator and a 2 micron fuel filter.  Microns are used as a measurement for the size of the particles that the filter will allow through.  Most factory fuel filters are about 12 microns, so the Air Dog II is 6 times better than the standard fuel filter.

In addition to the filtration that the Air Dog II offers, the system also pulls any air that is in the fuel and send this air in the form of foam back to the fuel tanks.  The system practically guarantees that your fuel will be clean and free of contaminants.  It has a fuel pressure gauge on it that will measure fuel flow restriction and alert you with a light to so that you know when to change the filter.

Only time will tell if this system is doing what it claims.  So far, so good and I don't worry about bad fuel anymore.  If the fuel pump fails, the system reverts back to just being a fuel filter.  I installed this fuel system last year and the pump lasted about that long.  When it failed they sent me a new pump under warranty for free and this is the detailed step by step procedure for replacing the fuel pump.

1. Here is the Air Dog II without the water separator filter ready for the pump to be removed.

2.First unplug the pump and then remove the water separator filter, then remove these 4 bolts.

3.  After the pump is unbolted, just lift the pump off and keep the check ball area clean.

4. The new pump is slightly longer than the older pump.

5. This is the new pump with the new O-Rings.

6.  When installing the new O-Rings, I had no problems keeping the O-Rings in place, but a small amount of grease can be used to hold them in place if they don't stay put.  Everything must be clean.  It is important to keep the O-Rings in position because you don't want to have a pinched O-Ring.  A pinched O-Ring won't provide a good seal.  This went very easily.

7. Here is the pump placed on the dowels and lined up for bolting in.

8. Secure the bolts into the pump and torque them down to at least 20 lbs.  This is easily done without a torque wrench.  You are almost done.

9.  All that is left to do is screw the water separator on, plug the unit back in and run it.

And this completes the pump replacement of an Air Dog II Fuel Preporator.  It took about 15 minutes from start to finish and now the pump is quieter than before.