[Bill]

Jon:

Let me get this straight. Your Liberty dispenses rose petals AND has air leaks on the aux side.

Chuck

[Dana]

Chuck, we do not call air leaks, air leaks. That feature is what we call refreshing the pneumatic system.

We Liberty owners do not like to use old stale air to operate the rose petal dispenser or pocket doors, so our coaches come with a feature to insure old air is replaced frequently with new fresh compressed air.

A lot of older coaches, regardless of who the converter was now have this upgrade.

I hope that clears up any questions about why my aux compressor is heard running so often.

[Archived]

Threegreens, the culprit could also be an aux system leak.

Threegreens said “my air dryer purges every couple of minutes”. In my world “couple of minutes” is 2 minutes. This is in no way normal with any of the 5 MHs I have owned unless I was asking one of the three separate air systems to do something. He didn’t say “few”, “periodically”, or “occasionally” purges, which would be normal.

Do you have an aux pressure gauge on your dash like you have for brake pressure? If you do not, you have no idea what is happening with the aux system. If the aux system has a leak big enough to drop its pressure to 90 psi in a minute or two, the engine driven compressor will keep pumping the aux system back up and purging each time.

Brake pressure does not drop when you have an aux system leak. Each of three systems are protected from each other.

[Doug]

My bus didn’t come with a aux system pressure gauge on the dash, so I installed one. I installed another in the steer compartment.

There is some important stuff on the aux system. Like the suspension and its air bags, the air bags for the engine belts, and the parking brake. Your not going far without these systems. Less critical are: dump valves, genny air bags, step well cover, door lock, air horns, pocket doors, grill shutters, driver seat, etc.

IMO all of our buses should have an aux pressure gauge on the dash.

[al]

To check for aux leaks run the aux compressor while the coach is parked and not running . Then tell us how often that compressor restarts . I went from the compressor running every 5 min to one a hr . I replaced many push on fitting chasing pocket, air step and Genny air bag leaks . Good luck finding them all .

[Archived]

I do have an Aux pressure gauge in the steer compartment below the driver seat. I’ll check it next time I’m at the coach.

But the leak is likely somewhere in the wet tank, dryer and compressor/governor area. Such a leak would not show up on my gauges. In that case, the Bendix trouble shooting guide calls for installing a pressure gauge in the wet tank drain to confirm. That will have to wait until I put the coach up on the ramps for the yearly service later this summer.

[Gerald]

When I 1st bought this coach I rebuilt dryer, Put on a new governor and driving between houses I noticed the dryer purging every 10 or 15 seconds, all 3 gauges are at 120 psi but dryer is tied to wet tank and we don’t know what it’s doing. So next thing is I installed a set of unloader valves in the Truflo 750 compressor on the Detroit engine. Problem went away, that’s been more that 2 years ago and still holding. If it’s sitting at a fast idle or driving it only purges when it needs to.

[Dan]

Last year while driving down the road on a weekend trip, I noticed on the dash aux pressure gauge that the aux system pressure would drop from 120 to 90 psi in about 60 seconds. This is not normal. I only reason I caught this when I did was because I had installed a dash aux pressure gauge yrs prior. The problem was a large aux system leak that I could easily hear in the steer compartment at the next rest area.

Here’s a link on PC from 2016 when I did this install.

LINK