Air Compressor on Providence

[tedward1555]

Me again.. Tried to fill my tires yesterday with the hose that came with my RV, using the air connection above left of the Generator. For some reason the tires would not take more than 100 lbs of pressure. They should have 120-125. My dad suggested that the compressor was not capable of delivering that much pressure, or that I was using the wrong air connection. It is just beyond the air horns and it may be regulated down at that point. Does anyone know if this is in fact the connection I should use? Or is it somewhere else on the RV? Or does the air compressor on the fleetwood not generate enough psi to fill my tires beyond 100 psi?
As usual any help is greatly appreciated.
Ed

[MonacoMama]

It seems like many of the members here have an aftermarket portable air compressor that is carried. I do believe that the PSI ratings have something to do with it...along with how long it takes to get the tires up to pressure.

Am I right, Folks??

[Gary RVRoamer]

You probably have the right connection - it is just difficult to get much more than 100 psi from the onboard air system. It probably has a max pressure of 125, but does not maintain that pressure as a constant. The compressor cycles off at 125 and comes back on at a lower pressure, around 100 psi or so. That means when the tire pressure exceeds a100-105, the pressure in the tank is enough to keep the compressor from turning on and mo more air moves into the tire.

One trick that some people use is to pump the coach brake pedal a few times to drop the pressure further, causing the compressor to turn on and boost it back to 125. Then squirt a bit more air into the tire while the onboard system is still at 125 psi. That way you can gradually build up more pressure in the tire. It's going to be slow, though. A pressure differential of only 10-20 psi between the onboard tank/compressor and the tire means that air is not going to move into the tire very fast.

If away from home, I would use the onboard system to get the tire to 100 psi or so and then drive to a truck stop that had a high capacity tank/compressor to top it off. At home I use my Porter Cable pancake compressor (150 psi).

[Gary RVRoamer]

Quote:

I do believe that the PSI ratings have something to do with it...along with how long it takes to get the tires up to pressure. Am I right, Folks??

A compressor has both a psi rating and a CFM (Cubic Feet per Minute air volume) rating. You need enough of both to fill a large RV tire. It is easy and cheap to build a compressor with a high psi rating, but it takes more effort & cost to get a decent CFM rating at high pressure. Small compressors typically advertise a high psi and don't want to mention that the CFM is very low at that pressure, maybe 0.1 CPM. For a 22.5" RV tire, you need more like 2.0-3.0 CFM to delver enough air to fill it at high pressures.

[Elkhartjim]

Just a question Ed, are you sure you need that much pressure? That is usually the max pressure allowed. Have you weighed your coach? That is the only true way of determining the correct air pressure. You need at minimum to weigh the front and then the rear axles, then go to your tire mfg web site for correct pressure for your size tire. I run 90# on front and 85# on duals. Sure rides better than when I was running at max pressures.

You're still saving money on this forum, uh?

[Gary RVRoamer]

He may not need that much psi on the Providence, but my American Tradition (somewhat heavier but also with larger tires) runs 105-110 on the front for its scaled weight. All depends on the load and the tires used, which is why the tire pressure tables need to be consulted.

[Elkhartjim]

Quote:

Originally Posted by RV Roamer [Gary] 105-110 on the front for its scaled weight. All depends on the load and the tires used, which is why the tire pressure tables need to be consulted.

[Batman_777]

I have the Providence and only get about 100-108 psi from the MH onboard air. I carry a separate Porter-Cable compressor just for that reason. It is a 6 gallon 150 psi pancake style compressor. Works great and a 6 gallon working tank can air up a house.

[tedward1555]

Thanks Batman and all. ElkhartJim, I just have always heard from my Dad that full tire pressure meant better mileage and less wear and tear. I did stop at a Camping World this afternoon and they filled them for free. Of course, I filled up with propane, joined the Presidents club, and spent another $125 bucks... So a little air was the least they could do... Now I need to get a pancake air compressor. Does it work well plugged into a RV outlet? Do I have enough elec juice to run it?
Thanks everyone
Ed

[tedward1555]

Quote:

Originally Posted by Batman_777 I have the Providence and only get about 100-108 psi from the MH onboard air. I carry a separate Porter-Cable compressor just for that reason. It is a 6 gallon 150 psi pancake style compressor. Works great and a 6 gallon working tank can air up a house.

Our motorhomes are identical in color and paint scheme #2. Hope you are lovin' yours as we do ours.'
Ed

[Elkhartjim]

Quote:

Originally Posted by tedward1555 always heard from my Dad that full tire pressure meant better mileage and less wear and tear. Ed

I understand. I would still recommend weighing your mh and use the pressures recommended by the tire manufacturer. It won't hurt the tires to run them at max inflation but the ride and handling can be extremely different. I promise you, you can blow them up like a balloon and get .0001 more mpg but you will never put enough miles on your tires in the next 5-7 years to wear them out. They will crack a long time before you wear them out.

Search this site for tires pressures and you will find the common thought will be-weigh your motorhome.

[tedward1555]

Quote:

Originally Posted by Elkhartjim I understand. I would still recommend weighing your mh and use the pressures recommended by the tire manufacturer. It won't hurt the tires to run them at max inflation but the ride and handling can be extremely different. I promise you, you can blow them up like a balloon and get .0001 more mpg but you will never put enough miles on your tires in the next 5-7 years to wear them out. They will crack a long time before you wear them out. Search this site for tires pressures and you will find the common thought will be-weigh your motorhome.

Good advice as always Jim. I will weigh them.... One question... have seen the scales set up next to the diesel pumps at truck stops, but have been a little afraid to drive up on them to get a weight... scared all the truckers will laugh and the scale master will tell me to beat it over the loud speaker. Are they ok with weighing RV's? And do they charge for it?
Ed

[Elkhartjim]

Its okay. They do charge...less than $10. I use my local farmers co-op and they are so surprised to see something other than a grain truck...they all stare. Also scrap dealers and major moving companies have scales.

[Gary RVRoamer]

Quote:

Now I need to get a pancake air compressor. Does it work well plugged into a RV outlet? Do I have enough elec juice to run it? Thanks everyone

A 150 psi compressor will take nearly the full rated output from a 15A outlet, so don't have anything else running on the same circuit at the time. Other than that, your RV outlets and generator or shore power will do fine.

But do you have to air up so often that you need to carry a compressor? If so, you may have a leaky valve or a tire that is poorly seated on the rim. Tires should not lose air on a daily or weekly basis and a good one will seldom need air at all. Of course, you may need to add air if you change altitude or climate substantially, but how often does that happen? You can always air up when you stop for fuel at a truck stop.