On-Board Air I


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     Ok here it is.... It's cheap and it's easy. I'm using my stock A/C pump and an old fire extinguisher. 95 psi at your disposal.

    The tank is easily removed and used as portable air. If you used a female fitting on the tank hose. Which I didn't do. In a jam I can easily switch a fitting or two.

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     From this tee one hose goes to the tank and one goes to my grill. With the tank removed, I can still pump directly to the the air hose. Which is how I started out.

     I use the ARB cutout switch, but any will do. I like this one because it's so small. It Cuts out at 95 PSI and back on at 85 PSI. A small tank is the key, so the pump cycles and stays cool.

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    I wired my idle control motor to the system, so that it kicks up the idle while the pump is on, and returns to idle when the pump kicks off.

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relay.jpg (23827 bytes)     This glob of silicon is a double pull-double throw relay(DPDT).  It switches the polarity of the current to the idle control motor as the pump cycles.
 tank.jpg (25078 bytes)    A fire extinguisher works great because you can hook so many things to it. I took off the handle and all the guts, then used a bolt to plug the hole. Or you can tap the hole for another air fitting. Eventually I'll have an in cab gauge and ARB's hooked to it. You will need to run the ARB's air supply through an oil/water separator. Some things will need to be moved around the engine compartment in order to make the tank fit.

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Hit the A/C switch and your ready!!!!

Getting Started

   To get started, you can use the pump without a tank. All you have to do is bypass the A/C low pressure cutout switch. Then buy the appropriate adapter fitting and connect a male air fitting to your pump. Connect a hose with a free flowing chuck and pump away. You must use a male fitting and a free flowing air chuck because there is no high pressure cutout switch!!!! Air will flow constantly.

  Cost Estimate

Pump: Free, if you have one

Tank: Free. Fire extinguishers can only be used so long before they have to be replaced. Try your local fire station.

ARB Switch: or so. Or get one off a junk air compressor


Assorted air fittings:-

Hose: - depending on quality.


>>Feed a cap of engine oil to the inlet of the pump every couple of trips.

>>The faster your engine is running the faster it pumps. Mine is adjusted to 1,500RPM

>>Give the pump a break after each vehicle. They get warm, but that's to be expected.

     I haven't setup a filter for the inlet yet. Not sure I'm going to. It's been working for  6 years now, and I have an extra pump.