Auxillary Air Compressor

[dale farley]

I've read some of the previous posts about auxillary air compressors. Does anyone know if I should have one on my 93 Marathon? If so, where would it be located?

[Coloradobus]

Roadruner,

Take a look at your breaker panel in the bedroom to see if you have a breaker labeled, "Air Compressor. If it labeled, it maybe behind you front bumper. Anothe place to look for an air compressor, is on top of your generator, that is where Marathon placed air compressors in later years.
Do tell what you find. I shooting in the dark here.

[mike kerley]

Our 93 CC has it located behind the generator, second bay. Access through a small hatch in the first bay, drivers side. Ours has a power switch in the first bay marked "aux air compressor". 12 volt item. To work on it, I pull that section of the bay wall out.

Mike K

[jello_jeep]

Mine is mounted on the generator, have seen lots of Marathon's with a smaller unit mounted in the "shoebox", an area hidden by the lower door under the driver's window.

I had spoken to one chap who said he had to replace that small one every 1.5 years or so, and actually carried a spare

[dale farley]

I will check out these places in the next couple days. My coach is at a friends house at this time. I probably didn't ask the right question to begin with. I am reasonably sure I have a small compressor for the accessories such as the step slide, etc., but according to my manual, the compressor for the accessories is not connected to the air bags.

I saw some posts that said you could run the compressor to level the air bags if they were down. I am not sure if I have any way to do that without starting my engine?

[dalej]

Dale if you have a aux. compressor that is plummed in the aux tank of thr bus then you can level the bus, that is why they us aux air. some comvertors like marathon 96 time frame didn't use them but its not that big of deal, you just add one yourself. The idea is so you don't have to stat the bus to level the coach. I have Level Low.

[Jon Wehrenberg]

If your coach does not have an aux. air compressor in some respects you may have an advantage.

Certain coaches that have aux compressors do not have sufficient aux. compressor air pressure to level a coach, so starting out having to add one allows you to make certain the one you add can do the job.

Every coach varies because the converters have different axle loadings. For example a coach with a generator near the front, especially a 40' coach, is going to need a lot of air pressure (probably around 120 PSI) to raise the front of the coach.

Conversely, a coach with the generator towards the rear on a 45' shell, may only require 95 or 100 PSI to raise the front.

Without making a big science project out of it you can determine how much air pressure you require by letting the bus air pressure drop to about 80 PSI, and then using a portable compressor and a regular tire pressure gauge put air pressure to the bus and check the pressures as the front raises. Each increase in height requires more pressure, so monitor the pressures along the full travel.

For those who already have aux compressors and are having trouble getting the front to rise, you can cheat a little by picking up the tag axle. That takes a little weight off the front axle and will allow the air bags to extend a little further. After you mess around trying to level your coach that way however, you will come to the conclusion it is a whole lot better to just fix the leaks.

[MangoMike]

A HOW TO: to add an air gauge to monitor your Auxiliary Air Tank.

http://www.prevoman.com/Pages/Aux%20Gauge/Auxpg1.html

mm

[win42]

Air Compressor Selection: At POG2 some of us ran down to Home Depot and bought a 110V compressor to use as a tire pressure portable unit. I have been toying with the idea of piping from it's temp. storage location to the Aux air location and use it for aux air suppliment. It usually takes overnight for the coach to drop the front end. The rear does not dop. No Jon, I have not found the air leak yet, but I will continue to look.
I'm hooked up to shore power 99% of the time when parked, so I don't think a 24V compressor is manditory. If you boondock a lot then yes it would. Mike; adding the pressure gauge was a good move. If I follow the course described above I will add a pressure regulator to the line to avoid adding the 145 PSI the compressor is capable of to the Aux. air system. "Stand a back it's a biga dange!" I don't want to add fuel to the little glowing problem I allready have.

[MangoMike]

Big Harry,

If your leaks are relegated only to the front end you're in luck, so to speak. I believe all the Norgren valves are up front with 2 or 3 in the steering bay. Start w/ blasting those suckers with your high tech soapy leak detectant and see if anything arises. It just may be one of those up front norgrens. Worse case it's the ride height valve located in the center between the wheels over the axle or possibly a leaky air bag(s).

Let us know.

The War on the Leans continues...

mm