Custom AirDog 150 Install
Doing a custom AirDog install I think the hardest thing that people struggle with is getting the draw straw installed properly in the proper place. First of the draw straw should not be installed in the sender basket. The reason is the return fuel from the rear of the head is heated by the heat of the head and that will be the first fuel you going to pump back to the VP44. We all know that you want cool fuel for the VP44 this is a bad idea. Second, your draw straw needs to be installed in the fuel tank away from the sender where the hot fuel is returned. I typically use the high spot just forward of the sender which typically has no other interference from the bed or frame.
Installing the Draw Straw
First off you need to drop the tank and have it fully drained of fuel. It is a requirement to have the tank completely empty of fuel when the measurements are done for the straw. Diesel fuel weighs about 6 pounds per gallon so when you fill the tank the bottom will deflect more opening the gap more between the straw tip and the bottom this is why the gap must be 1 or 2 quarter coins at most. Then place the fuel tank on 2x4 boards under where the bands normally sit to keep from deflecting the bottom of the tank upwards which will skew your draw straw measurement. When you drill the 1-inch hole do it in a place like I mention the high spot forward of the sender. Using either 1 or 2 quarters place them under the tip of the Draw Straw so you can mark the proper amount to trim off. Now remove the straw and measure the same distance from the tip and mark and cut. When you cut the straw make sure to cut it straight! NO ANGLE CUTS!... MUST BE CUT STRAIGHT. Now install your Draw Straw you'll need the gasket on first. Then install the straw then the flat washer, star washer, and the nut on the inside. Tighten the nut, yeah it's not easy to tighten that nut on the inside. Then add your fitting to the straw when you do make sure to face it so you can hook up the fuel lines.
Mounting the AirDog 150 pump to the frame
When I now install the pump I did not use the supplied bracket for mounting the AirDog sandwiched to the frame this typically ends up with the filters hanging below the frame line and striking damage might occur if you use your truck offroad. This is why I use the base bracket and mark and drill the frame for placement so the filters are above the frame line. In this case, I mounted the AirDog 150 on the outside of the frame. Now you want to drill and tap the frame for the bracket. I used a drill just a bit small but the 5/16-18 tap requires a 17/64 drill bit. Once holes are drilled and tapped then you need the four Allen bolts supplied in the kit and the plastic block spacer. Tighten up the four bolts and then install the AirDog in the bracket.
Installing fuel Lines / Hoses
Since this truck has a flatbed and modified filler neck. I had taken advantage of the custom filler neck for my return line coupler. I pulled out the double barbed fitting and replaced it with the AirDog return fitting. Then I measured from the AirDog 150 return fitting to the return barb. Cut the hose. Now use some lightweight oil and lube each push lock fitting and push them into the hose. The easiest way is to put the fitting on the floor and push down on the fitting with the hose. All you got to do after the hose is put together with both fittings is snap it on each fitting at the return and the pump. Now Supply from the tank you measure from there and route back to the pump. The same applies here cut to length and then push your push lock fittings into the hose. Then snap on the draw straw and the AirDog. Now the feed line to the engine is a bit different than most do. I route the feed line over the frame and then run the hose inside the frame all the way forward to the hole near the bell housing. They exit the frame and run to the stock Fuel Filter housing. For this one you have to push the fitting on by hand being the hose is run in the frame already. Again just snap the hose onto the AirDog pump and then on the stock fuel filter. Now I ordered the optional Big Line Kit which goes between the stock fuel filter housing and the VP44. The stock filter housing is always kept when I do an AirDog install. The extra filter does catch things that the AirDog misses. The stock fuel filter heater helps for wintertime operation. I highly suggest you always keep the stock fuel filter housing.
Electrical / Wiring
The AirDog kit comes with all the electrical and fuse hook-up. Again this is all ran back through the frame with the fuel lines to prevent snagging electrical while offroad. I typically mount the relay to the cowl using the ground screw of the wipers on the driver side. The positive and negative hook-up will require trimming there are over 6 feet of excess wiring there. I do NOT hook to the battery ever. I hook the ground to the bolt of the PDC for ground. The positive line I hook up to the PDC positive post. This way there is no wiring that will be damaged by battery acid. Then you need to unhook the factory lift pump lead and hook up the AirDog signal lead to the factory lead.