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 back in the mid-90s (no longer available), but has been refined after over 10 years of extensive field use. The 4air system will let you air up all your tires at the same time and maximize the air output of your air source. As soon as the first tire is connected to the air hose, air will be flowing from your air source into your tire. As you hook up each additional tire, air continues to flow to all connected tires with pressures equalizing automatically. So all the while you are moving from tire to tire connecting the hose, air is flowing. So the minute or so you spend connecting all the tires is used to pump air into your tires. And unlike using a single air hose to air up one tire at a time, you may be wasting that time between filling one tire and moving to the next one.
Sure, you may have an air tank in the system to let your compressor store air between tires, it is likely of a small capacity and as it fills, the pressure can rise quite high, cutting into your compressor output. An advantage of the 4air hose is that you are essentially using the tires as your air tank and tires are much larger than a typical air tank. What that means is that if you have a small "tank" and a large "tank", the pressure in the large tank will rise much slower than the small tank for a given flow rate. And look at any compressor flow vs. pressure rating and you'll see the flow drops off as the pressure rises. So if you have a small air tank in your system, its pressure might rise to 90 or 100 psi in between tires. For example the compressor we use in our shop truck puts out 2.2 CFM at 0 psi but that falls to 1.8 CFM at 30 and about 1.0 CFM at 90 psi. So if I take a minute to move from one tire to the next and the small 2 cu.ft. tank in the truck hits 90 psi, the compressor output falls to about 1 CFM, so at that point the compressor output has dropped in half. With the 4air system, airing up tires from say 8 psi to 30 psi, as each tire is connected initially, the pressure is low, down around 8 - 10 psi, so the compressor output remains fairly near it's maximum output, perhaps 2 CFM. So you can nearly double the effective air output by keeping the air pressure as low as possible for as long as possible. This also puts less load on your compressor motor (assuming electric) and keeps the heat buildup in the compressor itself, higher pressure = higher temperature. And if you have no storage tank with your compressor, then if you move from one tire to the next tire, the compressor will shut off and you get 0 CFM out of your compressor. Pretty simple to do the math there if the compressor is not running, you are not filling your tires.
This system has a number of benefits:
The 4air system is available in 3 standard sizes:
We also can make systems to handle 2 (2air), 4 (4air), 6 (6air) or more tires, as you need. Systems are designed to work with tires up to about 44" in diameter (thus 24" length of the stub hose at each tee fitting). 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 chucks at all tires provide hands-free airing up and down.
The standard configuration includes 2 - 56" long hoses from the central air manifold to the first tee, where a 24" long stub hose is attached to connect to the tires on that axle. 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, $1.50/ft. for standard hose (4air-ash), $2.00/ft. for extreme duty hose (4air-aeh). The 2air systems can be set up to handle tires on one side (2air-s, 2air-m, 2air-l) or on one axle (2air-a) of a vehicle depending on your requirements.
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 24 psi, 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. We prefer an air chuck and Schrader valve on ours, but you may want a Schrader valve and a gauge, 2 wheels or 4 or 6. With quick disconnect air couplers, you can change configurations in the field. Automotive type air couplers are readily available at hardware and auto parts stores, or we can supply custom setups. We also carry a small kit of fittings (see pictures following) including flexible air hose, quick connect tire chucks, various combinations of air hose couplers, so if we find an air source, we can usually air up from it, otherwise we use our on-board air compressor.
Some folks may look at a 4air hose system as a frivolous accessory or "bling". When I first saw one, I too thought the same thing. But after having and using one for better than a dozen years now, I can tell you it is the one off-roading accessory that I carry in my truck that I do use each and every time I go off-road, in fact at least twice on every trip. Once to air down and once to air up at the end of the trail. The winch on my truck has been used maybe half a dozen times in that same period of time. The Hi-Lift jack maybe twice that many times, my on-board welder, a couple of times, etc. But that 4air bag is right on top and gets pulled out at the start of the trail and I am always waiting for the other folks to finish airing down their tires and the sam thing at the pavement at the end of the trail.
Regarding the ParksOffRoad.com review of the 4Air system, we have identified the source of the slow air up/down times to a faulty batch of tire chucks that were internally restricting air flow. We have since changed suppliers for those parts and now test each and every chuck for adequate air flow upon kit assembly. So there should no longer be any significant difference in the time to air up or down one tire vs. all 4, since the basic bottleneck (source of air flow restriction) is the Schrader valve on the tire and not what is connected to that/those valve/valves.
Standard 4air system includes:
2air/4air/6air options include:
(1)(2)
(3) (4) (5)
(6) (7)
(8) (9)
(10) (11)
The question always comes up, "which is the best tire chuck?". That is a good question and the answer is "it depends". Think of it like a socket set for a ratchet wrench. There are 6-point and 12-point sockets, there are deep well sockets, impact sockets as well as the normal size sockets. So which is best? Well, for strength, a 6 sided impact socket is the best. But if you have a 4-sided nut, that won't work, so a 12-point socket is better. If you have a lot of thread sticking out of the nut, a deep well is better, but if the nut is in a tight space, a shallow socket might be better. So all the tire chucks work, we have used them all at various times and had them work fine most of the time, but run into situations where one or the other did not work as well. They have differing ways to actuate the locking mechanism, they attach to the Schraeder valve in a different orientation, they grip the valve stem in a different manner, etc. Typically the better the chuck seals, the more tedious it is to operate, so the screw-on chuck is a perfect seal, but takes a significant amount of time and finger dexterity to attach and remove. The clip-less seals pretty good, attaches and removes fairly easy, but does take more finger dexterity to operate than the two clip-type chucks. The clip-less and euro-style chucks also requires a direct in-line path to the valve stem, while the right angle clip-type chuck comes in at a 90 degree angle.
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:
Think of the manifold as one of those 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 Schrader 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 Schrader valve. Note that the digital gauge can't be installed on the manifold, it needs to use a Schrader valve connection.
I personally don't like having the pressure gauge hard mounted on the manifold (from years of experience).
Then, off the exhaust port and its quick disconnect air hose coupler, 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 Schrader 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.
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, although to try and keep things straight, we will refer to things that connect/disconnect air hoses as couplers and things that attach to tire valve stems as chucks.
Seems like every maker of anything to do with air has come up with a coupler of one sort of another. They all had perfectly good reasons for their own design, but invariably the different couplers will not fit each other.
Click on the image above for a summary of the most common air coupler designs. We use the Milton or Industrial (M or I) type chuck, since it appears to be the most common coupler 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" coupler. 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 couplers. We 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 coupler required:
Pictured above are the female and male Type T couplers on top and the Type I female and male couplers on the bottom. They are slightly different. Which one should you use?
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:
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.
Configuration of the 4air/2air system components is listed below:
So, which parts do I need? Well, it all depends on what you want to do.
The 2/4air-s/m/l hoses are set up assuming an air port in front of the vehicle with enough hose (56"/1.42m) to run to the front tire(s), as pictured here. If you have your air port some place else, like in back or on the side or your vehicle has an extra long front overhang, you may want more hose length to each side, so be sure to measure what you need prior to ordering. You can add additional hose to both side or one side or even specify that the main manifold is offset to one side or perhaps even in the middle of one of the side hoses. Grab some string, rope or garden hose and lay out the hose like you want it set up and let us know the lengths you need.
The systems will have an air control valve to let air in or out and a Schrader valve on the manifold to let you check air pressure with your tire pressure gauge or add air from a gas station air hose. The basic systems will also have tire valve chucks for all the tires they are designed to connect to and those chucks have automatic shut-offs to keep air from leaking out when not attached.
Then there are a number of adapters or upgrades you can add onto the basic system to suit your needs:
So, determine what all sorts of things you want to do with your 4air/2air system and the figure out which adapters/upgrades you need to do that. Or drop us an e-mail with a list of what you want to do and we can configure a system for you.
You can think of this system like a set of Tinker Toys, everything pretty much is plug and play.
About the only consideration you need to make is that there are male and female chucks and Schrader valves
And Schrader valves and different couplers.
And if you are looking just for tire valve chucks, we have those available
And don't worry, if there is some combination of chucks/genders/types that we don't list, ask and we can probably come up with a solution for you. The big advantage to our system is that we make use of standard 1/4" pipe thread fittings on everything so it is usually just a matter of screwing the right bits together to make up a custom adapter or fitting. Some examples of custom systems we have made are a 4air/6air system with quick disconnect couplers to separate the 2 extra hoses for the 6air system from the 4air. This owner had two different vehicles, one with 4 and one with 6 tires and wanted a syatem to work with both, but did not want the additional hoses getting in the way with the 4 tire vehicle.
Prices below do not include shipping, so after configuring your air hose kit, select a shipping option below...
Note:
- Extra large, custom air hose systems may not fit in the flat rate boxes and incur additional postage based upon size, weight and destination.
- We try to use USPS flat rate shipping, and as such, we can only fit one 2Air, 4Air or 6Air hose in a single box. Multiple systems will need to add separate postage, we'll try to ship in one large box, by weight, but if that comes out higher than 2 flat rate boxes, we'll ship the most economical way.
...
If none of the above systems fit your application, custom 4Air systems can be designed to exactly fit your needs. Examples of custom systems are extra long wheelbase and/or extra wide 4Air hoses for full sized pickups. For this application, just supply the wheelbase and/or track width of the vehicle and add the cost of the extra hose length to the cost of the desired system above (don't forget that you need extra hose on each side of the 4Air system). Other custom systems include 6-way air hoses for vehicles with dual rear wheels such as RVs or dual rear axles, such as trailers. Also available are custom locations for the 4Air manifold (the place where the air compressor connects). Other custom system designs have adapted the 4Air hose to fit up to a Scuba tank regulator with a user-supplied air chuck fitting. We have also designed systems for people who want to permanently install the air hose on their vehicle and then have quick couplers at each wheel well to connect up the 4 tire valv e chucks for airing up and down. We have supplied systems that have quick couplers in the middle or at the ends to convert say from a 4-way to a 6-way system. In one case, the customer had a 4x4 and also a motor home with dual rear wheels, so he wanted the 6-way hose to work on the RV but didn't want to drag the extra house around when he had the 4x4 off road. We have also designed custom systems for use on boat lifts or rafts that use multiple inner tubes for flotation.
If you have an idea for an air hose setup, let 4Crawler Offroad know what it is you want and we'll see if we can design something to suite your requirements.
For custom systems, just specify the lengths of each hose segment of hose you need to reach from tire to tire and where you want the air manifold located. For easier measuring, you can use a length of rope or garden hose to run from point to point, allowing enough slack in the rope/hose to allow for easy access and then measure the length of the rope/hose needed. These systems are prices based upon the amount of hose and fittings needed.
If you've read this far and are still confused as to what this is all about, perhaps a little background information is in order. Back in the late 1990's, an outfit called Quadra-Flate Enterprises was making a nifty gadget called the Quadra-Flate. They seem to have since gone out of business as far as I can tell. Anyway, when I got into 4-wheeling, I bought a Quadra-Flate system, based partly on this product review. Anyway, I used the QF system for a while, but began to run into some things I didn't like about it.
So after making all these changes, I ended up ditching the QF system and designed my own from scratch to avoid all these problems. The key features I found for off-road use are flexibility, reliability and redundancy. Over the years, I assembled a good collection of attachments for the QF system to make airing up and down easier.
I also designed the system so that it could be easily modified to adapt it for custom applications. All the fittings are standard 1/4" NPT (National Pipe thread Tapered), so you can unscrew one thing and screw in something else. For example, one customer uses his at an ocean resort where they need to pull boat trailers out of the water several times a day. He airs down then airs back up with a SCUBA air tank and SCUBA air fitting that simply replaces the quick-connect coupler. The pressure gauge, if you decide to use one, is easily replaced if damaged (trust me it *will* get damaged). I only use parts that I (and you) can easily obtain from most any hardware store. As such, I can built a 4air system to meet your needs, or you can modify it yourself if you are so inclined.
With the disappearance of Quadra Flate Enterprises and their excellent product, I wanted to make my version available so others could benefit from it. I find this is one of the most useful tools I carry in my 4x4, it gets used at least twice every trip. If you would like to own a real Quadra Flate, I no longer use mine and will sell it for $60 plus shipping. I've rebuilt most of the air chucks, the air valve handle is a bit broken but it still works. I could install a new brass valve for $10 additional. If interested, please contact me.
And, what's up with the name, anyway? When you pull out that coiled up hose and start hooking it up to your valve stems and someone walks up to you and says:
Harry Lewellyn wrote an excellent article on "Tire Pressures for 4-Wheeling", highly recommended reading.
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Visitor # 144161 since 13.AUG.2001
[Last updated: 17.December.2020]
