on board air

[redneckfarmer]

i was wondering how many of you guys had some sort of on board air compressor looking for suggestions i already have a small talk mounted under the bed and im pretty much decided on a hard wired 12 volt compressor but have no idea what brand or size to buy mainly will be used to air up tires on farm equipment and the truck ? what are you all useing?

[Jason S]

Welcome from Oklahoma. 

I've seen a lot of trail rigs using the air conditioner compressor modified with an air filter on the suction side and a hose on the discharge side for airing up tires. 

Alternatively, most of the farmers and ranchers around here have a gasoline powered air compressor somewhere in the bed (fleetside) or mounted (flatbed) that they use to air up tires. A lot of the gasoline compressors I've seen seem to be Honda...

Hope this helps some.

[gto109]

I've been wondering the same thing.

[alaskaskiff]

Service air on a truck is real useful.  On one truck that has an exhaust brake I use the tank/compressor for airing up.  The capacity is small, but I get by.  My Chevy was a prior service truck for a demolition company. It has a belt driven Iowa Mold And Tool air compressor on it. Kind of looks like the York AC compressors that Kilby Enterprises uses for their on board air. This is hooked to a 7 gallon tank and it rocks.  Not everyone has a 454 powered air compressor.  Thumps my shop compressor for CFM.

I would say to think about duty cycle and it's intended use.  The electrics are getting better, but a healthy electrical system may be required.  The belt driven style give huge CFM but come at a cost.

[bake74]

     I have done this many a time on jeeps for rock crawling.  The 2 easiest ways are 1: as mentioned a/c compressior with filter system going to storage tank and outlet for airing things up. ( this way will only work with the a/c compressor dedicated to air pump )
     2: there are several company's that sell 12v air compressiors and kits to mount in your vehicles for airing up tires, etc.  Depending on money spent, some are as fast as vehicles a/c hook up system.
     The cheapest route (which will only work for one time use without refill ) is a canister you precharge and store in vehicle and has limited usage before recharging.

[Isaac3384]

I have always used the Viair compressors. I currently have (2) Viair 444's for the air ride on my nissan. For what you are trying to accomplish, you should only need one. If it's going to be used very often, I'd reccommend 1 compressor for every 3-4 gallons of air storage capacity. The 444's are rated 100% duty cycle and can be purchased with everything needed to run them, except for wire. I run 1 4 gauge power wire that has an 80 amp fuse to a distribution block where two 40 amp fuses are mounted. From there, I run 1 8 gauge wire to each starter solenoid. I use the old chrome ford starter solenoids because they can easily handle the amp draw of the compressors. Then, the other side of the senoid is hooked directly to the compressor. On the control side of things, I have a switch mounted on my dash that feeds power to two pressure switches. Each pressure switch has a different psi setting for it to come on. This way, if I drop to 120 psi, only one compressor will run. If I drop below 100, both will run. The tank I use is aluminum, and all of my fittings are brass. I also run a water trap for each compressor to help prevent moisture in the system. The aluminum tank and brass fittings are all used to prevent rust. This whole setup has cost me around $500, but it's extremely reliable...

Viair makes quite a few compressors that would be suitable for what you're trying to accomplish; the 480c, the 444, and the 380c. You could probably find these compressors cheapest on eBay. Keep in mind, if these are mounted on odd angles, it will cause premature failure.

The starter solenoids I mentioned are also position sensitive; they need to be mounted on a verticle plane; i.e. The side of your frame, otherwise you'll have a problem with the contacts sticking.

The engine driven compressors are a good way to go. The one you would want is a York, and it will have a hexagon shaped head on the top. You can pick them up at junk yards off of old volvos for fairly cheap, but you have to add oil from time to time. Regardless what anyone says, oil will leave the crank case of the compressor with the air, there's no way around that. Also, keep in mind, you may have to fab up a bracket to make this work. I don't know if these compressors ever came on anything GM ever produced, so this may be worth looking into. You'll still want to run a manual cut off switch and a pressure switch.

The pressure switch I always run is made by Square D. It's cut off pressure is adjustable, and so is the differential pressure. It's kind of big, bulky, and ugly, but they can take a beating.

The only other compressor I would reccommend is made by Air Zenith. They are quite a bit more expensive than the Viairs, and in my opinion, aren't worth the extra money.

[redneckfarmer]

i had made up my mind to get a viair until i was at harbor freight and saw an electric air compressor that puts out .9 cfm at 90 psi  for $47 which shoud be fair for filling tires and keeping my small under bed tank full to honk my air horn its prob a piece of junk but has a year warrenty so ill see, if it is ill just take my money back and go for a viair   

[bake74]

      The harbor freight one will probably work, it will just take longer to fill up your tires.

[Isaac3384]

If you make sure you don't have any leaks, and run a pressure switch in line with an on/off switch, you shouldn't have many problems. Make sure you look at the 'duty cycle' of the compressor; since the cfm output is low, it will have to be 100% to be able to keep up. The nice thing about pressure switches is you can leave your on/off switch on while you're on the road and let it maintain pressure. If you have no leaks, it should only run a minimal amount of time. I would highly reccommend a manual ball valve between your tank and quick connect fitting to help prevent any leaks...Lord knows all of my quick connects leak like crazy...lol

Teflon all of your fittings, and if you use any compression fittings, use a little lubricant (I use 3-in-1 oil) on the compression threads to make everything seal a little better. Also, if you need to use compression fittings, you can use the ones from home depot, but the D.O.T. Fittings are much stronger and less likely to leak. I would make sure to use a 'line wrench' on the home depot fittings to keep the compression fitting from 'ovaling'.

You can accomplish what you're wanting to do pretty cheap, but in the long run, you get what you pay for.

 

[redneckfarmer]

i got it all hooked up today and im actulally suprised it will fill my small couple gallon air talk up to 75 psi in under 2 min i have it all leak proof for now and wired it up through a pressure switch off a junked out air compressor and ran a quick coupler up into the inside of my bed for easy acess now we will just see how long it lasts the good thing is if it quits the rest of the system is hooked up the same way for a better compressor all i have to do is swap compressors and it will all work again

[Isaac3384]

Good deal! Hope it works well for you!