Truck Compressor and Tank

[Completed Project]

Well some of you know that my truck is setup to be a rescue vehicle because I love helping people! Some time ago I bought a VIAIR 300P Portable Compressor, Boy has it seen some work! this little guy has filled more tires than I can count. But the common thing is that when I go help someone I usually have a few minutes to talk to them. Ether a phone call or pulling up behind to ask how things are going. This should be enough time to fill an Air tank that can speed up how quick I get them moving again. Or run an impact gun (omg this would be nice!) So I managed to find an old fire extinguisher.

Lets talk about that first, the extinguisher is referred to as a cartridge style: (Video of test on the back of the truck)

Note: Just added some updates Dec 03 2021

The important part about this tank is, it's hydro static tested to 350psi. This means I trust it to 250psi, though I will never go that high. not seen here, under the cover is two 3/4npt ports (keep in mind, that means they are about 1 inch in diameter if you measure them). The other bit of good news is, extinguisher powder is bio-degradable. Means okay to toss it out. BUT IT MAKES A HELL OF A MESS!!!! I had the fire extinguisher refill place take the powder as they say they re-use it. The tank came from such a place, it is called a "Cartridge Style Fire Extinguisher", make sure its made of steel or it will suck to weld and cost me 0$ (if you can tig, go ahead but its much easier to compromise the strength of an aluminum tank with cracks and not know for months)

If you ever heat / modify / impact the tank you must do a hydrostat test (search youtube for hydrostat test with a grease gun for instructions). When an air tank fails its not usually an explosion (under these pressures) its usually a fast leak but remember, in a car accident that would be different. I never keep the tank pressurized, only ever fill it when ready to use it. I occasionally test the tank but it gets such regular use I am not worried about it. I also empty and dry the tank once a year.

Once the tank is cleaned up, I did up a drawing to know what I was getting myself in to. First off, the over all design idea:

In the above drawing I dont take in to account the 75$ in little adapters lol. I thought I could do it all from spare parts. Yeah, not so much. Though I will say, if you get your hands on a couple dead air compressors it will make most of the cost unnecessary. After getting the drawing together it was frustrating because of part availability. So here is some gotchas.

-Design for 1/4npt parts on everything except the check valve.

-check valve would be in a perfect world right beside the compressor and be up at the air manifold.

-The Air out vales should be the universal quick connects. M type is the most common in my experience.

-I used pneumatic parts for the gauge to make it small as possible (more on that in a bit.)

-The Viair 300p is not ideal. doing it again I would have used ARB CKMTA12 (dual screw compressor)

Alright, The part availability...

Starting with the compressor side:

ViAIR 300P air compressor.

I got this by calling sportsman light truck in Kamloops. Super easy to deal with, shipped it to me no problem. Thanks Brady!

Hose and adapters:

Because of the CFM of this compressor and the PSI I am dealing with. I decided to use what Princes Auto calls Pneumatic parts. Because Air systems and Pneumatic parts are different. (The purchasers at PA are ether on drugs or have to listen to some stupid rules.... My money is on the first one...) The parts I used are:

-From compressor side:


--0434779 - 4-Way Universal Air Quick Coupler Body

--8002513 - 2 pc 1/4 in. NPTM Brass Couplings

--8092603 - Female Hose Coupler Pneumatic Fitting

--8134868 - 1/4 in. O.D. Polyethylene Pneumatic Hose - Blue (this is 100ft, you only need this once, but I will used the part over again)

--8092595 - Male Hose Coupler Pneumatic Fitting

--0400226 - 1/2 in. NPTM X 1/4 in. NPTF Brass Bushing

--8058317 - 3/4 in. NPTM x 1/2 in. NPTF Bushing

--8477374 - 3/4 in. NPT Check Valve with Bleeder Port

--0400259 - 1/8 in. Brass Pipe Plug (this goes in the side of the check valve)


Air Distribution Side:


--8058317 - 3/4 in. NPTM x 1/2 in. NPTF Bushing

--0400226 - 1/2 in. NPTM X 1/4 in. NPTF Brass Bushing

-- Princes auto you are a bunch of assholes when you randomly rename things! a "Whip Hose" apparently means short, and 3/8" apparently means 1/4" NPT connector with 3/8" hose... SO, the part number is 0430335 - 75 in. x 3/8 in. PVC Whip Air Hose

--8628745 - 4-in-1 Air Manifold

--8419251 - 1/2 in. NPT Plug (cause the hole on the back is not needed)

--8419137 - 1/4 in. NPT Plug

Remote Gauge:

--8092595 - Male Hose Coupler Pneumatic Fitting

--8134868 - 1/4 in. O.D. Polyethylene Pneumatic Hose - Blue (you already bought this, don't do it again!)

--8092603 - Female Hose Coupler Pneumatic Fitting

--8509390 - 1-1/2 in. 160 PSI Bottom Mount Air Pressure Gauge (PA doesn't tell you all three measurements, the on unlisted is 1/4in NPT!)

Pressure Switch:

--5713011 - 1/4 x 3 in. Long Nipple

--8482499 - 034-0226 PRESSURE SWITCH (up to you, but I just adjusted it myself using another compressor and a 110v light)

--5713011 - 1/4 x 3 in. Long Nipple

--8624967 - 1/4 in. Air Regulator (not what I used, but it should work)

--5713011 - 1/4 x 3 in. Long Nipple

--8625089 - 2-in-1 Air Manifold

--5713011 - 1/4 x 3 in. Long Nipple

--0434779 - 4-Way Universal Air Quick Coupler Body

--8507675 - 25 ft x 1/4 in. Rubber Air Hose

--0434779 - 4-Way Universal Air Quick Coupler Body

--8419137 - 1/4 in. NPT Plug

Check Valve:

If you are going to order from amazon or deal with vendors, you can find 1/4" NPT check valves. but I gave up and 30$ later I bought a 3/4" NPT check valve from Princes auto. LINK! (PA Part Number: 8477374). In the end this made life so much easier. I tried this shitty little 3 way 1/2" NPT check valve. This works.

Well that's the full list of parts and basically the whole design.

Here is a video walk though of the install in the engine bay and remote gauge:

Alright, things are moving along. I got the tank mounted under my truck (its a dodge ram 1500 2012 Hemi 5.7). Here is the tank on the passenger side:

The first pic is of the tank under the truck, hidden by the power step. Second pic shows what I settled on for mounting. Keep in mind if you ever weld to a tank you should hydro static test the tank. (rough video to watch, but it gives the idea how its done: I tested my tank to 350psi (just a little more than double what I am going to use it at). Then leave it for about 24 hours. No loss in pressure. If you loose pressure, FIND THE CAUSE!.

With the tank in place, I mounted the compressor on the side wall of the canopy. its a temporary solution while I wait for my screw compressor to arrive. I have a concern about how hot the line coming from the compressor gets. Normally a compressor uses copper pipe to dissipate the heat. Here is my design idea to address this.

This tank does not have any fins on it, but it should make a big difference on the temperature of the air going in to the 1/4" pvc flex line.

*** UPDATE: This copper tank is not needed on the screw compressor. Much cooler output for some reason ***

I really hope this info helps someone!!! leave comments here on the youtube video. The next bit of info will be the drawings for the bracket I had plasma cut at Sportsman Light Truck in Kamloops BC. And attaching everything to the truck. But it might have to wait until the snow is gone. (September 19 2018 right now).

I am going to upgrade the compressor from a ViAir 300P to a ARB CKMTA12 Dual screw compressor