2air/4air Tire Inflator/Deflator System

Contents:

• Description
• Specifications
  • Theory of Operation
  • Clipless vs. clip-on tire chucks
  • Air Chucks de-mystified
• Instructions
• Pricing and Options
  • Custom Systems
• Background

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:

• Transfer air between tires or between vehicles
• Equalize pressure between tires on the same axle (important for lockers)
• Air up a low tire without use of a compressor
• Saves time and energy before and after the trail run
• Increase driving safety
• Get longer tread wear on your tires

The 4air system is available in 3 standard sizes:

• Small
  • Up to 90" wheel base, e.g. Jeep CJ/TJ, Suzuki Samurai, Landcruiser FJ-40, Defender 90, etc.
• Medium
  • Up to 110" wheel base; e.g. Toyota 4Runner and short bed pickup, Jeep Cherokee, etc.
• Large
  • Up to 130" wheel base; Toyota Extra Cab, Landcruiser wagon, SUVs, etc.
• Custom lengths (longer or shorter) are available, too.
  • Add/subtract $1.00/ft. for standard hose and $2.00/ft. for extreme duty hose.

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.

Specifications:

Standard 4air system includes:

• 2 side air hoses
• 4 air chucks
  • Either the standard clip-on chuck
  • Or optional clipless chuck
• Solid brass air control valve
  • With a male quick-connect fitting installed in the inlet/outlet
• Schraeder valve for checking pressure or airing up from a service station compressor
  • Also available in a one-sided and one-axle configuration - 2air (i.e. one air hose and 2 chucks)
• A pair of captive velcro straps for securing the coiled up air hose

2air/4air options include:

• Built-in air gauge (replaces the schraeder valve)
• Quick disconnect air fitting for connecting to on-board air sources such as listed here:
  • Makes an excellent add-on for the PowerTank CO2 air system with the extreme-duty hose and brass fittings
• Coiled air hose with quick disconnect fittings for extending the reach of the system
• You can also use a user-supplied digital tire pressure gauge with accurate readings to 2.5 psi for getting really low
• Custom/extra ports on the central air manifold for custom connections such as SCUBA tank fittings, etc.
• Spare hose sections are available for fast field repairs
• Carrying bag
• For extreme conditions, I offer an extreme-duty version, with higher pressure, all metal fittings, hose flexible to -40°F(or °C).
  • The current hose and fittings are rated for 200 psi and -20°F.
• A 5th tire valve chuck and quick connect for use in airing up from a spare tire. Hook the 5th chuck to the manifold and spare, open the valve and use the air in your spare to increase the other 4 tires.
  • Assuming an equal sized spare, divide the pressure difference of the spare and the other 4 tires by 5, this is the amount of air you can increase the tire pressure by. For example, spare at 50psi, tires at 10psi, difference is 40psi, divided by 5 is 8psi. Therefore all 5 tires will end up at about 18psi (10+8) after they equalize.
  • More information on this available here.

• In the top-left picture (1) you can see the following:
  • The basic 4air system in the center (black hose and fittings)
    • An optional integral air pressure gauge to replace the schraeder valve port on the manifold block
    • Also pictured is a user-supplied digital air pressure gauge that can be used with the system, this is the one I personally use, reads to as low as 2.5 psi in 0.5 psi increments
  • An optional (yellow) coiled air hose with quick-disconnect fittings to hook you your on-board air compressor
  • Also pictured, below the digital gauge, are some adaptors I've found useful:
    • On the left is a quick-connect schraeder valve that can be used for airing up from gas station air compressors, handy if you have the integral pressure gauge installed
    • On the right, is a quick-connect coupler with chuck, to plug into the coiled hose if you only need to air up one tire, saves unpacking the larger hose
• In the top-right picture (2) you can see the original Quadra-Flate design and some of my mods:
  • The nylon T-fittings have crimped-on hose ferrules, making field repair or modifications difficult without the proper tooling.
  • The front wheel side hose section is too short for typical off-road tires sizes. This results in the whole hose hanging off the valve chuck, which can cause it to leak or fall off. I would have lengthened mine, but since the fittings are crimped, I couldn't justify the $150 for the crimping tool.
  • The length of the rear wheel hose is not long enough to reach between my 105" wheelbase 4Runner, if the valve stems end up on opposite sides, I have to air up the front then the back tires separately.
  • The cheap plastic handle on the main air valve broke off years ago, making it hard to operate and to see which way the valve is turned,
  • The integral air gauge got banged around in use and became inaccurate, I replaced it once then removed it and installed a schraeder valve. To measure pressure, just hook up your favorite gauge, to air up at a gas station, put the air chuck on the fitting, no fuss, no muss.
• In the middle-left picture (3), you can see a closeup of some of the various attachments and fittings I can supply with the system or you can add them yourself:
  • To the far left is a digital pressure gauge to use on your tires or on a schraeder valve on the 4air system
  • Just to the right of pressure gauge hose is a quick connect coupler and male and female 1/4" NPT fittings
  • Above that is a quick-connect couple with a schraeder valve installed, this is a quick way to air up from a gas station compressor, just clip this onto the 4air fitting and air right up. Just to the right of the coupler w/ valve is a separate schraeder valve that came with my Quadra-Flate system for comparison.
  • In the upper-right corner is a quick-connect press-on air chuck, which is a handy attachment with the extension air hose (pictured to the right) to air up one tire
  • Below the press-on air chuck is a clip-on air chuck, just like the ones used on the 4air system.
  • To the left of the clip-on chuck is a pipe thread to hose barb adapter, this would allow you to splice your existing 1/4" ID air hose to the 4air system or make field repairs, etc.
• In the middle-center picture (4) is a closeup of the coiled extension air hose with quick-connect coupler fittings.
  • I outfit my on-board compressor with one of these couplers (it shuts off the air flow when disconnected)
  • When I need to air up, I plug the coiled hose into the compressor coupler then plug the 4air into the extension coupler
  • If I only need to air up one tire, the coiled hose and the press-on air chuck are all I need
• In the middle-right picture (5) is a picture of the optional storage bag for the 4air system.
  • This heavy canvas bag is just the right size to hold the coiled air hoses and keep them from getting tangled and protects the hose and fittings from dirt and damage while not being used.
  • I also try to keep a tire patch kit and other tire-related items in my storage bag.
• In the bottom-left picture (6) is a close-up of the tire valve chuck options:
  • On the left is the basic right-angle clip-on chuck
  • In the center is the straight-on (Euro) style clip on chuck
  • On the right is the straight-on clipless style chuck
  • The clip-on chuck requires approx. 3/8" of valve stem thread to seat fully, while the clipless chuck needs almost 1/2", 3/8" threaded plus an additional 1/8" that can be unthreaded but the same OD as the threads.
• In the bottom-right picture (7) is close-up of the extreme-duty hose and all-brass fittings and clipless chucks.
  • This hose (Buna-N rubber) has a temperature range to handle CO2 inflation systems like the Power Tank.
  • It is also more flexible than the standard duty hose (thermoplastic rubber)
  • The brass fittings and stronger hose have higher pressure ratings than the standard hose and fittings
• All the 2air/4air systems make use of press fit hose fittings for clean appearance and tangle-free operation. No hose clamps to snag everything in sight, and unlike the crimped type hose ends, the all-threaded assembly allows for field modifications and repairs. For example, a 2air system could be converted to a 4air with a few extra fitting and hose sections. I found the crimped on hoses of my old Quadra Flate were a severe limitation to modifying it, which is why I ended up designing the 4air system.

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).

• First, the gauge is prone to damage and simply getting knocked out of calibration.
• Second, I like a separate guage, and I use a digital version
  • It is accurate down low and accurate up high
  • I like ONE gauge that is relatively accurate and reliable
• Third, I like to use the SAME gauge to check the 4air pressure and I like to double check the individual tire pressures
  • If you have two gauges, its unlikely they will both read the same
• One option for a gauge is to install it off a quick disconnect air chuck.
  • This will let you connect it when needed, take it off when its not.

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

• Connect to an on-board air compressor or Power Tank via an extension hose and female chuck
• Connect to a spare tire with another tire chuck and extension line to fill a low tire
• Connect a schraeder valve to air up at a gas station

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 me an e-mail and tell me 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.

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:

• Chucks to connect up to a schraeder valve on a tire
  • I have two types:
    • One that has an external clip
    • One that has an internal clip
• Quick disconnect chucks, of which there are many varieties
  • They come in male and female versions

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.

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:

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?

• If you already have air equipment set up with one type of chuck, get the 4air set up with that same type of chuck
• If you are planning to get air equipment set up with a particular type of chuck, then get the 4air set up the same way
• If this is your first air chucked piece of equipment, get Type I and then if you later add more air equipment, get Type I as well.
• If you later have to change, all is not lost. All parts are field replaceable, you can find replacement chucks most anyplace or I can supply you with the type you need.

Instructions:

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:

• To air down:
  • Unroll the hoses, running one down each side of the vehicle
    • Be careful to not place the hose too close to the tires at this point.
    • As you air down, the tire will flatten and trap the hose.
      • If this happens, you may have to roll the vehicle off the hose before you can put it away.
  • Remove the valve caps and clip on the corresponding air chuck
    • To prolong chuck and valve stem life, depress the lever on the chuck, push it onto the stem, then release it to avoid wearing out the threads on the valve stem itself. The retaining clip is spring steel but your valve stems are probably made of brass
      • Once the threads get worn too much, the chucks may not stay fastened securely
      • If you do wear out the valve stem threads, you can have them changed (good idea with new tires) or screw on a valve stem extender. I carry a set of these with me, also handy if you have hard-to-reach valve stems
      • With the clip-less chucks, you can also get a tighter seal by turning the chuck about 90 degrees after installing it, the opposing clamping jaws will follow the valve stem thread and "screw down" tighter
  • Open the control valve to release the air in the tires
  • Periodically test the tire pressure by closing the valve and reading the air gauge
    • With practice, you get used to both the air down time and also sound change as the pressure drops
  • When the desired trail pressure is reached, close the control valve and allow the tire pressures to stabilize and recheck.
    • Sometimes one tire will air down a bit slower and you may find that the pressure comes up a bit
  • Disconnect each air chuck, reinstall the valve cover and roll up the air hoses
• To air up:
  • Turn on your on-board air compressor so the tank is filling (if applicable)
  • Unroll the hoses, running one down each side of the vehicle
  • Remove the valve covers and clip on the corresponding air chuck
    • To prolong chuck and valve stem life, depress the lever on the chuck, push it onto the stem, then release it to avoid wearing out the threads
  • Connect the your air source to the 4air system
  • Open the control valve to allow air to enter the tires
    • If you are using a lower pressure built-in air gauge, open the valve slowly to avoid over pressuring the gauge
  • Periodically test the tire pressure by closing the valve and reading the air gauge
    • You can check pressure with the valve open, but it'll read a bit high depending on your air source flow rate
  • When the desired street pressure is reached, close the control valve and allow the tire pressures to stabilize and recheck, sometimes one tire will air up a bit slower and you may find that the pressure drops up a bit
  • Disconnect each air chuck, reinstall the valve cap and roll up the air hoses
• A couple of tips when using the 4air system:
  • Sometimes the air chucks will stick open and allow air to leak out, this most often happens when you are airing down, since the internal pressure is low. Usually rapping the chuck on the side of the tire or the ground will knock the internal piece loose that seals the chuck. I also find a shot of silicon spray into each chuck once or twice a year helps keep them working smoothly.
  • If you find the air chuck levers get tangled in the hose as you unroll it, take some electricians tape and wrap it around the lever and chuck body. I color coded mine with different colors on each side so I could sort out the two side hoses easier.
  • I carry a set of metal valve stem extensions in my air up kit. In the event you run into a valve stem that won't hold the chuck, or a tire with too short a valve stem, simply screw on an extension and hook up the chuck.
  • One option is to combine the 4air system with the Oasis Off Road automatic tire deflator
    • By setting one of the Oasis deflators to your normal off-road tire pressure, you simply screw it onto the 4air system and it'll take all 4 tires down to that pressure, without the hassle of getting all 4 deflators set to the same exact pressure. Here's a picture of the Oasis Deflator installed on the 4air manifold
    • If desired, a single Oasis deflator is available for US$25.00 for use with the 4Air system.
      • Deflators are adjustable for 5-20 psi cutoff pressure and screw onto a standard schraeder valve, either on the 4Air manifold (if no guage is present) or on a 4air-sv quick connect schraeder valve.
      • For faster deflation times, you can air down the tires most of the way with the open air valve then when you are 5-10 psi above your target pressure, install the Oasis deflator and let it take the pressure down the rest of the way. The Oasis deflator is somewhat flow-limited, so while airing down all the way with the deflator does work, it can take about 3-4 times as long as the 4Air alone. So by releasing the bulk of the air before attaching the Oasis valve can help speed things up.
      • You can also carry several Oasis deflators and have each one set to a different pressure if you use different tire pressures for different conditions. For example 20 psi on gravel roads, 15 psi in the rocks and 10 psi in the snow or sand.
  • When using the clip-less chucks, see below for proper use:
    • Pull back on the housing to release the spring tension on the internal gripping jaws as shown below-left
    • Then slip the chuck over the valve stem, pressing it down firmly before releasing the housing as shown below-right
    • Removal is the reverse, push down on the chuck and pull back on the housing to release the jaws
    • While it is possible to push the chuck down over the threads, the hardened steel jaws will quickly strip the soft brass threads on the valve stem

• If using the 4Air system with a CO2 type air tank (Power Tank for example)m you may find the air valve gets too cold to handle due to the extremely low temperatures of the expanding CO2 gas.
  • In this case, use the valve on the CO2 tank to turn the gas on and off.
  • You might also be able to wear a pair of heavy gloves to insulate your hands from the cold.
  • Or use a long, coiled polyurethane air hose between the CO2 tank and the 4Air valve. This may let some of the cold dissipate before reaching the air valve.

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.

• With the 4air all by itself I measured 2 minutes including one stop to check the air pressure at 1 minute (this is for all 4 tires combined).
• With a single Oasis Deflator on one tire, I timed about 4.5 minutes for the same pressure drop.
• With a single Oasis Deflator on the 4air manifold, I timed about 15 minutes for the deflation.
  • It seems the Oasis Deflator is flow rate limited to something under 1 CFM.
  • The advantage of this setup is there is no need to "baby sit" the deflator, you can be doing other things while the tires are deflating.
  • Or, for faster deflation with the Oasis deflator, first let out the majority of the air through the main air valve, then as you get to the last 5 psi or so, close the main vale and let the Oasis deflator finish up.
• Of course, smaller tires will have shorter times and larger tires will have longer times, directly related by the tire volume which I have listed on the page referenced above.

Pricing and Options:

Pricing for the 4air system components is listed below:

• The lengths below refer to the wheel base capabilities of a given air hose setup.
  • Ideally, select a system with a length equal to or greater than the wheel base of the vehicles(s) it will be used upon.
• Any part numbers with links will bring up an image of the item.

  2air / 4air - Options and Pricing

  Part	Description	Price (US$)
  4air-s	Small (90") 4air system	$95.00
  4air-m	Medium (110") 4air system	$100.00
  4air-l	Large (130") 4air system	$105.00
  2air-a	One-axle 2air system	$60.00
  2air-s	Small (90") 2air system	$65.00
  2air-m	Medium (110") 2air system	$67.50
  2air-l	Large (130") 2air system	$70.00
  4air-30	0-30 psi gauge	$15.00
  4air-60	0-60 psi gauge	$15.00
  4air-100	0-100 psi gauge	$15.00
  4air-ext	Coiled extension hose w/ chucks	$15.00
  4air-sv	Quick-connect schraeder valve	$10.00
  4air-ac	Quick-connect/spare air chuck	$15.00
  4air-bag	Heavy canvas storage bag	$20.00
  4air-edh	Extreme Duty Hose	+ $30.00
  *4air-edf	Extreme Duty Fittings	+ $12.00
  *4air-clc	Clip-less chucks	+ $10.00
  4air_pt	Change to Type T air chucks	+ $10.00
  4air_ash	Additional Standard Hose	+ $1.50/ft.
  4air_aeh	Additional ExtremeDuty Hose	+ $2.00/ft.
  4air_dfl	Automatic deflator valve (Oasis)	$ 25.00

  NOTES:

  1. * Clip-less chucks are available as a separate item at $9.50/ea. for upgrades to existing air systems
     1. + Add to cost of base system for upgrade, price shown for 4air, divide by 2 for 2air
  2. * Not pictured, but also avaiable are the euro-style clip-type chucks for the same price as the clipless chucks. They feature a straight on design, vs. the right angle of the regular clip=type chucks, and have a more secure engagement than the regular clip-type chucks
  3. All parts are field serviceable:
     1. 4Crawler Offroad can supply replacement hose sections, chuck replacement kits, etc. as needed
     2. For example, on the clip-on air chuck, the inner rubber sealing washer can wear out over time
     3. A quick fix that will nearly double its life it to open up the chuck, remove the washer and flip it over to start using the un-worn surface
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        3. Typical shipping time is 6-10 days
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    • PO Box 61092
    • Sunnyvale, CA 94088-1092 USA
  • Via USPS-COD (Collect On Delivery - US only) there is an additional charge for USPS-COD, typically $7.00

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  NOTE: 4Crawler Offroad/MissingLinkZ will be on reduced operations until 07.JUL.2008. New orders may not be processed until that date and e-mail response may be delayed. Stay tuned to this page for updates.

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  Custom Systems:

  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. Basically if you have an idea for an air hose setep, let 4Crawler Offroadknow 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, alowing 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.

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  Background:

  

  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.

  • First off, I found you needed 3 hands to operate the thing, one to hold your air chuck, one to hold the QF manifold and another one to open and close the air valve to check the air pressure. So I installed a quick-connect coupler so I could just plug it into my on-board compressor.
  • I already mentioned the gauge problems, so I installed a standard schraeder valve stem on it so I could hook up nice accurate digital pressure gauge that I carried separately.
    • This also let me use the same gauge to check the tire pressure separately.
    • I found using two different gauges only meant that I didn't know what pressure I had, since its hard to find 2 gauges that read the same.
  • I assume the QF was originally designed for use on a Jeep, as it would probably be ideal for an 80" wheel base vehicle.
    • Any more than that and the hoses may not always reach, and in any even they seem to have been designed to fit 26" street tires, not the 33"+ off-road tires that I run.
    • And since the hose fittings were crimped on, any modifications to the unit meant tearing it apart and replacing 90% of it.
  • Also, the chintzy plastic air valve handle was not up to the rigors of off-road use.

  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.

  • For example an air chuck on a quick-connect coupler is handy for airing up one tire (for example after plugging a puncture or reseating a bead) without having to unroll the entire set of hoses.
  • Also, the air chuck by itself makes a handy tool for airing down one or two tires, push it on the valve stem and out comes the air.
  • The long hose set is useful by itself, I have hard-mounted my on-board air compressor, so I need a long enough hose to reach all 4 tires, with the QF and now the 4air I can not only reach all 4 tires, but reach them all at the same time. The schraeder valve stem on the 4air manifold lets me hook up an air gauge, but it also handy at filling stations, where you can't disconnect the air chuck from the hose. This really pays for itself at those coin drop air stations, you can just get everything hooked up, drop in your quarter and get all the tires done in one shot. You save the time of running from wheel to wheel and fumbling for more quarters in your pocket.

  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 fitting. 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:

  "What is that thing for?"

  You can reply:

  "Its 4air!" ( for air :)

  Harry Lewellyn wrote an excellent article on "Tire Pressures for 4-Wheeling", highly recommended reading.

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  [Last updated: 16.June.2008]