22.5 tires/air volume

[k9dad]

I have 22.5 " tires on my 2011 Fleetwood Southwind. My portable home compressor is rated for 110 PSI. I took it to the place where I store the RV and attempted to put air in a few tires that were reading low.I like to keep 100 PSI in all 6 of my tires. The compressor would not handle it.In fact I lost some air in the tires. I called my son-in-law (mechanic) and was told "if the volume of the tire is greater then the compressor tank volume,the compressor would not put out enough "constant" PSI to put air in the tires". I guess this is the case. To make a real long story short,can anyone with 22.5" tires recommend a small portable compressor that will have the ability to put out 110 PSI into a 22.5" tire? I plan on going cross country in the late spring and will need to carry a compressor on board for obvious reasons.

[racerguy]

I bought a small portable compressor (not 12V) at Home Depot for under 100 bucks that works great for anything like this.

It will even run from my 1000 watt portable generator when needed. It's called a Husky Air Scout. Makes 2 SCFM @ 90 PSI and a max of 135 PSI.

This is the best small air compressor I've ever purchased.

[Rick_Jay]

What Alan_Hepburn stated is true. To simplify things, you want a compressor in which the "cut in" pressure is greater than the maximum pressure you want to put in your tires, or else you will be faced with the problem you experienced.

Since that number isn't always stated in the specs, a good rule of thumb is that the cut in pressure is usually 20-25 psi less than the cut out pressure (maximum psi). Plus you want to maintain a pressure differential from the tank to the tire as there will be pressure loss through the air hose & chuck.

So taking your 100 psi desired number, adding 25 psi for additional cut-in pressure plus another 10 psi for tank/tire differential, I'd recommend looking for an air compressor with a maximum psi rating of at least 135 psi. 150 psi would be even better.

Once you have sufficient pressure, than you can shop by the volume ratings CFM (or SCFM). The higher the SCFM number, the faster the compressor will be able to fill your tire at a given pressure.

My 5 hp 30 gal. home compressor with it's 110 psi max/90 psi cut-in would not fill my motorhome tires through the length of air hose I needed to use. IT had PLENTY of volume (SCFM) but didn't have the pressure to push the air from the tank into the tires. I bought a smaller Husky model with a 135 psi max. that I can bring to each tire and it works fine. I air them up to the max of 110 psi for the winter, then reduce to the proper pressure in the spring when we put the RV back in service. The compressor fits nicely into a storage bay.

I also use this compressor to blow out the air lines for winterizing. (I only use the pink stuff down the drains and the commode.) Because of this, I chose an oilless compressor as I didn't want it spraying oil into my water system. Something to think about if you're going to use this compressor to winterize as well.

You should be able to find a suitable 120VAC compressor which meets your needs for somewhere in the $100-$125 price range.

Good Luck,

~Rick

[Alan_Hepburn]

How compressors work: most have a built-in switch that turns the motor off when the tank reaches a maximum pressure, and then turns the motor back on when the tank reaches a minimum pressure. So, you turn the compressor on and it starts filling its tank. If your limit switch is not adjustable, it will run until the tank reaches 110 psi, when it shuts off. Now you connect the hose to the tire and open the valve - if the tire has 90 psi in it then the tank will attempt to push more air into the tire. But, the compressor's tank may not hold enough volume to increase the tire from 90 psi to 100 psi, and the pressure in the tank will drop - eventually the tire and the tank will be at the same pressure and no air will flow either direction.

Here's where the minimum pressure switch comes into play - at some point the pressure in the tank drops below the pre-set minimum pressure and the compressor will come back on to replenish the air in the tank. But, if the tank and tire have equalized at some pressure above the mimimum, it will never come on so you're stuck with that pressure. You need to stop pumping air and release some air from the tank so that the compressor can refill the tank. Remember - the tank MUST be at a higher pressure than the tire for air to move from the tank to the tire...

[RayChez]

Check the Home Depot stores. I bought a real nice compressor there, but mine has a eight gallon tank which holds up to 125lbs. I keep 100lbs on the front tires and 90lbs on the duel tires on the rear. If you put too much air you take away a lot of the smoothness on the ride. My coach weights 30K diesel pusher, I am not sure what yours weighs, but it seems like the air pressure is a bit high on the rear.
But Home Depot has different configurations on compressors. Some small enough to handle what you want.

I used to have a small compressor that I had bought at WalMart with no reservoir and it claimed it could pump up to 150lbs. They lied! It could barely fill up a car tire much less a huge 22.5 tire.

[sdbounderdiesel]

I have a VIAIR 400P Portable Air Compressor that is very compact, comes in a sturdy canvas carrying bag with a coiled 30 ft. inline guage/air hose. Max Pressure is 150 psi and I routinely use it to air up my tires to 115-120 psi. I've had mine for about 6 years now with no problems at all. Check it out. If you decide to buy one, check around for the best price. I've seen quite a variation in prices for this thing. I think VIAIR also makes a 300P model which may be adequate for your needs. Good luck.

[Sully2]

brao wrote:
I have 22.5 " tires on my 2011 Fleetwood Southwind. My portable home compressor is rated for 110 PSI. I took it to the place where I store the RV and attempted to put air in a few tires that were reading low.I like to keep 100 PSI in all 6 of my tires. The compressor would not handle it.In fact I lost some air in the tires. I called my son-in-law (mechanic) and was told "if the volume of the tire is greater then the compressor tank volume,the compressor would not put out enough "constant" PSI to put air in the tires". I guess this is the case. To make a real long story short,can anyone with 22.5" tires recommend a small portable compressor that will have the ability to put out 110 PSI into a 22.5" tire? I plan on going cross country in the late spring and will need to carry a compressor on board for obvious reasons.

How much air do you think you need in those tires?? Im sure you dont need a true 110 PSI in them to carry a Southwind

[PastorCharlie]

I would recommend at least a 2 HP with at least 4 CFM and a 3 GAL. tank and set the regulator at least 120 PSI.. The larger the tank the more volume it will hold and the quicker the tire will fill.

If you do mind spending your retirement years airing up the tires anything less will do.

[daveshan]

As has been stated it takes a pretty good pressure differential to fill tires, trying to get to 100 with a 110psi compressor just won't cut it. Add to that most manufacturers lie through their teeth (well exaggerate a lot) to boot.

I use my 140psi shop compressor at home and carry a CO2 tank with a fixed 150psi regulator for the road.

[MountainAir05]

I use a 2200 lb Nitrogen bottle the small bottle with a 150 double regulator. Your onboard compressor should also work. If not look at Viaircorp 440 and 450 Models.

http://www.viaircorp.com/portables.html

[Yaj]

I carry one of these personal compressors . It takes awhile but it'll get the job done!

[down_home]

Even the onboard compressor won't fill the tires, even those on Semis or at least Freightliner.
I'm not sure how they determine the pressue they put out but it is not logical since a 125 lb pressure compressor wont fill a tire to 110 lbs or even 100 sometimes.
They make an air doubler. Ives seen one on the Internet,a little pricey. They did come installed on Newmar. I've seen small 150 lbs compressors with twin tanks but they quite making them. You should have plenty of ac power on board and at least a couple, of compartments with ac plugs. It does take up valuable space to store one that is capable. The air doubler or pressure doubler can be installed in the compartment where the air compressor chuck is. There is plenty of room in ours.

[txtode]

I have a 1.5 gal Craftsman 150 PSI that takes care of filling my tires to 110PSI with no problem.

[wny_pat1]

Get a 6 gal 110v pancake compressor and run it off your generator.

Most 12vdc compressors just do not have what it takes to air up 22.5 tires. You can also consider using a compressed CO2 air tank system from one of the big box stores. You will find some info here: Tire Inflator Comparison Some of them will work.

[kdk]

Most diesel motor homes will have a air coupling in the front to air up the tanks in case a tow is needed. I purchased two twenty foot coil air hoses and a chuck for airing up the tires. Your engine driven compressor should be putting out about 120 psi and you can tap into that system using the air hose. Good thing also it is dry air unlike the little portable compressors. Can also be used to blow up tubes and air mattresses ect.
Blessings; kdk