Portable Tire Air Compressor

[gwilly]

Brett,

Thank you for the welcome! Lots of good information available on the Forum.

After I couldn't locate an air chuck outlet in the Generator compartment or engine bay of my Freightliner chassis model 36B, 360 HP Diesel pusher I asked my RV mechanic for help. He couldn't find a factory installed outlet either; and, frankly, he wasn't very interested in installing one for me. Too much work? What ever his reason, he promptly steered me towards solving my problem with a portable compressor. My experience with portable air compressors in the past have left me unimpressed and I'd like to find a more satisfactory fix that won't sacrifice storage space and add weight. Per your recommendation I will check with our local Freightliner service center for advice and maybe have them do a retrofit if feasible and not too expensive.

I like the chassis installation concept, There is a great video on the "RV Geek" web site that demonstrates a home made air chuck manifold that allows for one person tire servicing. The manifold incorporates a "T" connector with a pressure gauge and relief valve and finally an in-line shut off valve. Once the chassis compressor reaches 135 PSI you begin filling the tire while monitoring the in-line pressure gauge. When the in-line pressure gauge drops to the desired tire pressure shut off the air flow to the tire, then using the relief valve bleed off the in-line pressure until the compressor starts and recovers back to desired tire pressure or greater and resume filling the tire. No need now to have someone cycle the air brakes to bleed off pressure to start the compressor. I thought it was pretty slick.

One more question since I've had lot of different opinions on what is the best tire pressure from both web site forums and friends. The placard in my coach says the Cold Inflation Pressure for both the front and dual tires is 120 PSI. Whereas, I keep hearing/reading that most folks use tire pressures much lower between 100-110 PSI. The placard doesn't offer a range of pressure, just a fixed 120 PSI. Another question for Frightliner I guess. Your opinion?

Gwilly

[dickandlois]

Hi Gwilly,

There is a maximum Rim pressure stamped into the Rim, one needs to look for them and the numbers a not that big. With your Vin number and a call to Freightliner Custom Chassis, they can fill in the gaps. They also have the air line drawings on file for Chassis by Vin number, so there might be a convenience one hidden somewhere !!!

The Rim pressure is the max. one can go. Steel rims are generally around 110 psi and Aluminum Rims top out around 132 psi.

Rich.

[jc21014]

I to had been a little skeptical with most portable compressors ability to pump up those big ole mh tires. That changed when several members on other forums recommended this one from Sears. I bought one and it will do the J O B.

http://www.sears.com/shc/s/p_10153_12605_00915309000P?mv=rr

[wolfe10]

Again, call your chassis maker for the location of the air plenum. That will supply high pressure DRY air.

As far as tire pressure, go to your tire manufacturer's website WITH the heavier wheel position on each axle to determine the correct minimum PSI.

There is no one (hopefully) who will try to tell you the correct PSI without knowing actual weights.

The GAWR sticker shows correct minimum PSI if each axle is loaded to maximum GAWR. You may be well under that or even over-- only a scale will know for sure.

[gwilly]

I appreciate all the replies to my questions. All had valuable insights and recommendations. I'm retired AF and I know how much I liked and appreciated "After Action Reports" so with your collective indulgence I'll bore you (hopefully soon) with progress reports. Thanks again to all of you.

Gwilly

[GrampaDennis]

I to had been a little skeptical with most portable compressors ability to pump up those big ole mh tires. That changed when several members on other forums recommended this one from Sears. I bought one and it will do the J O B.

http://www.sears.com/shc/s/p_10153_12605_00915309000P?mv=rr

I bought the same compressor, based on this recommendation and a review from an RVer on the Sears site. It arrived today. I adjusted the pressures on my 1998 Southwind 32V with it. Right now, I'm doing 80 psi on the rears and 85 psi on the fronts. This little compressor did the job just fine. I can't say I'm in love with the tire chuck that came with it, though. I'll probably upgrade that.

On the first night out of a recent trip, we pulled into a Wal-Mart and called some friends to come visit. Our friend noticed that my right outside dual had gone slack. (It turned out to be a loose valve stem extension.) We got some air at one of those $1 for 3 minute compressors at a service station. What a wimpy compressor that was! It took 3 bucks to blow up our tire! That was the event that convinced me I wanted my own compressor on board. (Mine is a gas MH with hydraulic brakes - no built-in air system).

[tireman9]

That works, I don't have a TPMS on my coach.

I think running an RV without a TPMS would be like running without an oil pressure gauge or without engine temp gauge or without voltmeter.

[desertdeals69]

I agree 100%.

[wildebill308]

Frank,

Did you watch the update to that video?

They added a bleed valve before the gauge so you could bleed down the pressure standing at the tire.

Bill