RV Tire Inflation on the Go: Portable Air Compressor

When we purchased our used Class B motorhome it needed new tires. The tires had plenty of tread but had “aged out” at over 6 years of age. In addition a close inspection revealed small cracking in the sidewalls. Our local tire shop had several options for the correct Load Range E tires our camper required. We opted for the less expensive Sumitomo brand, which the store claimed others had used with great success. It was a bad mistake. The poor handling was only part of the problem – apparently the sidewalls were not as stiff as many Load Range E tires.  After several flat tires (thankfully no blowouts) that required tire replacement (tread separation, sidewall damage) we bought a set of the more expensive Michelin tires and our tire troubles went away.

viair-300p-labelHowever while we were in the midst of all the tire problems  – which typically occurred in the most inconvenient locations and in the worst weather – we realized we should carry a decent tire inflater at all times.  We tried four different air compressor products that for one reason or another didn’t work.  They either couldn’t reach 80 psi, took forever to reach 80 psi, didn’t work at all, or they broke.  The fifth try was a VIAir 300P from Amazon.  It was more expensive than the others, but it worked perfectly and has proven durable.  It has been almost 6 years since we bought it, but the Michelin tires hold their pressure so well that this compressor had not seen much use.

gauge-at-80psiWe recently developed a slow leak in one of the rear tires that we have had to watch.  Sitting in a campground a couple of weeks ago we were packing to leave.  Ah, better check the tires.  Oops, the left rear is a bit low again.  Better get it looked at when we get home.  So we fished our great little compressor out of the Stowaway2 box and found we couldn’t unzip its nice carrying bag.  Even some PB Blaster and a pair of pliers didn’t help!  We ended up cutting the end off the bag to get out the compressor with its cables and hose!

If you haven’t found a good portable air compressor to handle the tires on your Class B, you may want to consider this one.  Except for the problem with the carrying bag zippers after 6 years, the VIAir 300P has been wonderful.  Other users have complained about the hose not being long enough, but it reaches all the tires on our 19 ft camper.  If your camper has a longer wheelbase, you might want an extension hose.  VIAir does make a more expensive model, the 400P-RV especially for big motorhomes.  It comes with two hoses and extra attachments.

clamp-on-batteryThe 300P is easy to use.  And it is so much faster (and quieter) than our pancake air compressor in our garage at home.  Open the hood, put the clamps on the battery terminals, start your engine, attach the hose, and turn on the compressor.  The hose has a thumb lock end for a secure connection to the valve stem.

valve-stemYou might discover that you cannot clip to the valve stem because the hubcap blocks the way.  You can pry off the hubcap with a screwdriver.  When you reinstall, make sure you align the hubcap correctly with the valve stem so the hubcap fits snugly and the valve stem is where you can check the pressure with a gauge.  We have lost enough hubcaps to outfit several Dodge Roadtreks over the years!

inflatingThe pressure gauge on the 300P is close but inconsistent so we always check with the regular tire gauge to make sure we are at the 80 psi rear and 65 front that is the required air pressure for our Roadtrek.  Check the sticker on your door jam to see what the recommended pressure is for your tires.  Note: The 1998-2001 Dodge vans had a Tech Service Bulletin on handling that changed the recommended tire pressures, so if you have a Dodge Class B of that era, your door sticker many not show the correct tire pressures.  Read the TSB for correct information.




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  • ron

    Thanks Roger for the info,my air compressor takes forever,and has lost its power going upto 80psi,also I have air bags on rear so they often need to be adjusted,also everyone says that Michelins are the way to go,mine are on 6th year lots of tread,hopefully they last for a few more years

  • Jeff

    Having long involvement with off roading I can recommend with out reservation a line of compressors that are designed for, used and survive in a harsh environment. ARB compressors. These can be vehicle mounted (usually mounted unobtrusively under the vehicle), or portable kits. Kits come complete with a 19ft air hose and also all the necessary fittings for tire inflation and camping or leisure gear. CKMTA12 comes with a built-in 1 gallon tank and capable of powering air tools. Maximum PSI ranges 100-150. With 0.70 to 4.68 cfm.