[Dan]

Tim – this is what my 120 Thomas compressor looks like mounted on the rear of the gen.

Tom & Nancy 02 Marathon H, 732 08 Avalanche LTZ

[Jerry]

“Jon has the “quality” issue right.

One of the past owners of my bus replaced the original Thomas 12v compressor with a Viair. That compressor lasted less than three years, which is why I now need to replace it, probably with a Thomas compressor. ”

I am not opposed to saving money. Look how much I save by not having a smart phone. My concern is twofold. Our aux compressors can play a very large part in our use and enjoyment of the coach. On some coaches it is a critical component because slide coaches with inflatible seals must have pressure. Other coaches must have pressure for the suspension system otherwise the tag axle air bags dump air. Regardless of why we need the aux compressor in some cases we really need it and a good reliable compressor is often worth what it costs.

The second reason is unless our coach system can isolate the compressor we may be compromising the accessory system with a compressor and associated air lines and fittings that don’t even come close to DOT standards. It would be a crime to have a trip interrupeted because a Harbor Freight quality compressor has compromised the accessory air system. I especially feel this way when the cheap compressor is still mounted on its air tank.

[Corey]

Jon, seems to me that the importance of aux air is akin to the importance of a fresh water pump. And I have seen your backup water pump. So just wondering when the backup aux compressor makes it to the top of your list?

[Archived]

My back up compressor is on the engine.

All kidding aside, if the water pump fails there is no way other than a city water connection to flow water in the coach.

If the aux pump fails, compared to a water pump failure that is an inconvenience. I can get along without operating pocket doors and bed lift. My seals are important for the slides when parked, but if I lose aux air I am going to start the coach, lean it enough so rain water runs away from the seals, and only run the bus to build aux air as needed. Whenever the engine is running I will have aux air. Unlike the situation with a failed water pump.

[Archived]

After a couple hours of trying to trace down my aux compressor problem, finally cleaned the pressure sensor switches under the driver’s compartment (which Leon recommended) and problem was solved.

At some point I know I’ll need a new aux compressor, but I now have a much better understanding how to replace it than I did before.

[Richard]

Jon

Are you able to fit that compressor in your xl2?

My compressor failed Today I have a spare like the one you posted I am going to try installing it tomorrow we are in Sacramento CA, if you have any suggestions please post it or email. Thank you. In the morning I will try installing it hope I have space for it.

[Archived]

Hish,

The original Gast was a 1/3 HP and while the replacement is 1/2 HP it will fit, but it was not an easy remove and replace.

The new compressor has a “can” on the top of it that the original did not have. Because of that the support has to be lowered down. It has four mounting holes that attach the compressor support to the framework, so I dropped it down one set of holes, and redrilled the second set to reattach it to the new location.

Then the compressor would fit with no height interference. I had to slightly open the mounting holes in the foot of the new compressor so they would go over the studs in the mounting sound isolators. Everything else was no change.

I worked from my pit and just removed the bottom screen and worked at the replacement from the bottom. I probably could have pulled the entertainment center but I don’t think it would have made the job any easier or saved any time.

[Michael]

thanks Jon I will start this morning will see how much space I have in the h3 hope I don’t have to go under the coach to install it . There are two ports on the 1/2 hp compressor plug one side or tee both sides?

[Kevin]

Only one port is the compressed air on mine. It had a cap plug in it. I believe the compressor is a two stage which is why it appears both sides can be used but on mine one cylinder pressurizes the intake air for the second cylinder.

[Archived]

Jon the compressor job completed yesterday had to modify the base all is running.

Had an alarm, the front slide seaL ruptured, I believe the cause is the 114 F in Arizona for a week Had the turn off air supply to the front seal. Will get the seal replaced when we return to Florida.

[Richard]

In the meantime, if you are parked and there is a threat of rain, just tip the coach slightly so water runs off the slide, not towards the coach. When driving, using the OTR I would open the baffle that blocks outside air so there is positive pressure in the coach.