separator

2air/4air Tire Inflator/Deflator System

Visitor # 50497 since 13.AUG.2001

NOTE: Due to an inconsiderate user, 4Crawler.com was recently off-line due to exceeding it's monthly bandwidth usage. This situation should be resolved now.

separator

Contents:

[Return to my ForSale main page... ]

Description:

Air pressure in your tires is the one of the most important factors that affect the performance of you vehicle off-road. Too much air and you loose traction, damage tires, break drive line components and have a rough ride. Too little air and you may loose a bead, pinch the tire between a rock and the rim, damage the rim, etc. With experience, you'll learn to choose the correct pressure for the type of terrain you'll be traveling over. However, knowing the pressure you want and getting the tire pressure in all 4 tires to that value is time consuming if you have to do one tire at a time. There are numerous products on the market that can speed the process for airing down, but none also help you when you air back up at the end of the trip.

You can now air down or up in one easy fast process, all 4 tires at once, with the 4air. Air down all four tires from 30 psi to 10 psi in about 90 seconds and assure exact tire pressure in each tire. Quickly air up all four tires at once, too. Sizes to fit most 4 wheel drive vehicles. This system is modeled after the Quadra-Flate system popular a few years ago, but has been refined after 4 years of extensive field use.

This system has a number of benefits:

The 4air system is available in 3 standard sizes:

It is designed to work with tires up to 44" in diameter. The hose lengths are designed to accommodate the maximum wheel base in the size range above (including the worst case situation of having valve stems end up on opposite sides of the wheels), but can be used on vehicles with up to 15" longer wheel base if needed. Built with high-pressure 1/4" ID hose and uses 1/4" NPT threaded connections throughout for easy repair or modification. Quick release air chucks at all 4 tires provide hands-free airing up and down.

The standard configuration includes 2 - 4.5' runners from the central air manifold to the first tee. This is setup works will for connecting to a front mounted air source. If you wish to use the 4air from a rear air source or you have a very wide axle or extra long front overhang, additional runner length is available, $1.00/ft. for standard hose, $2.00/ft. for extreme duty hose.

For emergency use, you can air up a low tire by connecting the 4air to the low tire and your spare or to one or more good tires. The air pressure will self-equalize. For example, with one flat tire and three good ones at 32psi, you should end up with four tires at 24psi, which would be enough to get you home.

Most importantly, the 4air, unlike the Quadra-Flate, is designed for total flexibility. With the use of standard pipe thread fittings, it is possible to reconfigure the unit to meet your needs. I prefer an air chuck and schraeder valve on mine, you may want a schraeder and a gauge, 2 wheels or 4. With quick disconnect air chucks, you can change configurations in the field. Automotive type air chucks are readily available at hardware and auto parts stores, or I can supply custom setups. I carry a small kit of fittings (see pictures following) including flexible air hose, quick connect tire chucks, various combinations of air chuck adapters, so if I find an air source, I can usually air up from it, otherwise I use my on-board air compressor.

Be sure to see the product review on the 4x4Wire.com!

[back to the top]

Specifications:

Standard 4air system includes:

2air/4air options include:

(1)4air system and options(2)Quadra-Flate system, modified

(3)Closeup of various attachments (4)Closeup of coild extension hose (5)4Air Storage bag

(6)Clipless vs. clip-on chuck (7)Extreme-duty air hose and fittings

[back to the top]

Theory of Operation:

The key to the 4air (and 2air) system is the central manifold. This is the key part that connects the two sides together to a common point and is also where the main controls are located as well as where optional accessories can be added:

Basic manifold:
- Male chuck
- Control Valve
Schraeder valve		 Adding options:
- Clip on schraeder valve
- 30 psi gauge replaces the
schraeder valve

Think of the manifold as one of these round Tinker Toy pieces to which you can plug in various rods and other parts. You have 4 ports, two go to each side hose, one has a manual valve and exhaust port for airing down. The 4th port can have something in it. I prefer the basic schraeder tire valve, it lets me check the system pressure with a gauge, I can air up at gas stations, etc. If you prefer, a pressure gauge can replace the schraeder valve. Note that the digital gauge can't be installed on the manifold, it needs to use a schraeder valve connection.

I personally don't like the gauge hard mounted on the manifold (from years of experience).

Then, off the exhaust port and its quick disconnect air chuck, you can add other accessories for other purposes:

All these options are not meant to be confusing, its just a very flexible system. I have developed and used them all to address various needs in years of field use of the 4air system. Start out with the basic system and as you use it and encounter situations where you need to do something different, chances are. I've come up with something to address that need.

The tire valve chucks (either clip-on or clip-less) include automatic shutoff valves inside so they only flow air when connected to a schraeder valve on your tire. If left disconnected, they shot off the air flow. This allows you to connect the chucks to the tires without the air leaking out of the connected tires. Also, it allows you to set different pressures for different axles. For example, if you wanted to air up your back tires to 25 psi and the fronts to 30 psi, you could air up all 4 tires to 25 psi, then close the air valve at the manifold, disconnect the 2 rear tire chucks, then re-open the manifold valve and continue airing up the remaining 2 tires to 30 psi. With tires connected to the air hoses, and the manifold valve closed, the air pressure in all the connected tires will equalize automatically in a few seconds.

If you still are having trouble configuring a system for your own needs, send 4Crawler Offroad an e-mail and tell us what you want to be able to do and I can help you configure a 2air or 4air system to fit your needs. As mentioned elsewhere, I've set up systems to work off of Scuba tanks, I've built systems for big rigs to air up their "dualies", I've made systems that let you air up from a spare tire, etc.

[back to the top]

Chucks and more Chucks:

If you are confused by this chuck and that chuck, so was I (and still am to some degree :). In this page, there are two basic types of chucks:

Seems like every maker of anything to do with air has come up with a chuck of one sort of another. They all had perfectly good reasons for their own design, but invariably the different chucks would not fit each other.

Air chuck types

Click on the image above for a summary of the most common air chuck designs. I use the Milton or Industrial (M or I) type chuck, since it appears to be the most common chuck design. Air tools use it, most hardware and auto parts stores carry it and there is even a "universal" female chuck that fits both it and the type "T" chuck. Type T is made by TruFlate and is supposed to be a superior design (according to TruFlate) and they are pushing it for automotive use. The folks at Power Tank sometimes use type T chucks. I offer an upgrade to Type T chucks with the 4air_pt option (see below). If planning to connect the 4Air system to another air system, be sure to check the type of chuck required:

Type T on top, Type I on the bottom

Pictured above are the female and male Type T chucks on top and the Type I female and male chucks on the bottom. They are slightly different. Which one should you use?

[back to the top]

Instructions:

4air in action

Using the 4air system is very easy. In the picture, above, I've connected the 4air hoses to my valve stems, then connected the manifold to my compressor, using a coiled air hose. The chucks stay on the valve stems and I can walk away and do other things while the compressor fills the tires. To air down, just open the air valve and let the air out, in detail:

Pull back on housingSlip chuck over valve stem and release

One benefit of airing up all 4 tires at once, is that it slows the rate of pressure rise. This allows you more time to get your gear packed for the trip back home, re-connect sway bars, mud flaps, etc. without having to constantly check air pressures. With 33x9.50 tires and a 2.2 CFM on-board compressor, it takes about 6-7 minutes to air up from 15 to 30 psi, or about 2 psi/minute. With larger 33x15.50 tires it takes about 15 minutes to go from 10-30, so you have plenty of time to do other things without checking on the tire pressure or moving the air hose from tire to tire. If you have a high-capacity air system, this may not be as big a benefit, but for an electric compressor, this alone will pay for the system.

I have a page with information on tire inflation and deflation information located here. I did some timing measurements with deflating a set of 33x10.50-15 tires from 30 psi to 15 psi.

Important Note:
If you have a 2air or 4air sustem with a buit-in gauge, especially the lower pressue versions, you need to excercise a little caution with how you connect the system and use it. What you want to do is avoid over pressuring the gauge with air. So for example, to air up your tires, you would first want to connect all the air chucks to the tire valve stems. Only then do you want to connect your air source to the chuck on the inflator manifold, doing so with the air valve closed. Then, slowly open the air valve to allow air to flow into the tires. If you were to first connect the air source to the manifold and open the air valve, the air hoses (and gauge) would run up to air pressure of your air source, maybe 100psi or higher.
Several options are avialable if you still wish a built-in gauge but want to be able to disconnect it when not needed. You can order the gauge of your choice with an extra air chuck to screw onto the gauge and a scraeder valve to screw into the manifold. This way you can clip the gauge to that manifold schraeder valve and it'll work just like it is built in and you can also use that same guage on individual tires as well. Another option is to attach a female quick disconnect on the manifold and a male quick disconnect fitting on the gauge and this way you can put the gauge in place and it'll be as solid as if it were screwed into the manifold and you can easily unplug it if needed.
And fear not if you do happen to over pressure the gauge. You may notice that the gauge reading is off afterwards. But it is a simple matter to unscrew the face off the gauge and remove the two small screws in back and slide out the gauge workings for adjustment. There is a copper "Bourdon Tube" that operates the gauge. Is is essentially a flatten copper tube wound into a "?" shape. It is very easy to adjust the tube, just like they do in the gauge factory. Take a pair of small needle nose pliers, wrap the tips with some tape to protect the soft copper. Then gently fold the tube near the middle of the curved part (you don't want to apply any force on the pliers) and gently twist the tube inward to reset the needle. The way the tube works is that as pressure builds inside, it tries to straighten out (kind of like one of those party toys you had as a kid). So if the tube is over pressured, it will be a little too straight and you want to gently bend some curve back into it. Start easy and give just the slightest twist with the pliers, then release the tension and see where the needle points. If it needs to go farther to sit properly at 0 psi, then repeat the twist with just a tiny bit more pressure and recheck. Once you get the feel for it, you can usually get the needle back to 0 in a few tries. The key is to be GENTLE, you don't want to crush or kink the tube. I have used this technique many times and it has worked well for me. Have even used it to "calibrate" the gauge for a more accurate reading, at least compared to a second gauge. This way I can make say 30 psi on the 4air gauge match 30 psi on my regular tire gauge.
[back to the top]

Pricing and Options:

Pricing for the 4air system components is listed below: