Air 101

[Ray,IN]

Originally Posted by hypoxia

Every 2-3 years is what the Monaco manual said.

[MN_Traveler]

Originally Posted by hypoxia

Every 2-3 years is what the Monaco manual said.

Im sorry … i kind of mis stated. I really meant to imply that the dryer is not changed automatically as part of the same service for either the oil filters or fuel filters. You have to ask for it as a discrete service. I am definitely aware of the factory recommended intervals. On the other hand, my freightliner service place has definitely said said that for the usage profile for an RV, that might be overkill … and that the ulitmate test is whether pulling the lanyards reveals any moisture coming out of the tanks. Changing the dryer is not a bad idea, but i was just trying to say i would not automatically suspect it unless therevis moisture in the tanks.

[Iceclimber]

Originally Posted by MN_Traveler

Im sorry … i kind of mis stated. I really meant to imply that the dryer is not changed automatically as part of the same service for either the oil filters or fuel filters. You have to ask for it as a discrete service. I am definitely aware of the factory recommended intervals. On the other hand, my freightliner service place has definitely said said that for the usage profile for an RV, that might be overkill … and that the ulitmate test is whether pulling the lanyards reveals any moisture coming out of the tanks. Changing the dryer is not a bad idea, but i was just trying to say i would not automatically suspect it unless therevis moisture in the tanks.

For me, after reviewing my last invoice and knowing the previous was not on top of things I will change mine. Not quite sure where my lanyards are to release moisture.

[MN_Traveler]

Originally Posted by Iceclimber

For me, after reviewing my last invoice and knowing the previous was not on top of things I will change mine. Not quite sure where my lanyards are to release moisture.

The lanyards are attached to valves in the bottom of the air tanks. When you pull them, the valves open and purge air out of the tanks. They are *specifically* designed to expel any water from the tanks that might have accumulated there. I think the guidance for truckers is that this is done on a daily basis? In either case, if the dryer is working correctly, there will be no water in the tanks (i have never had any). But if the dryer is not fully functional, you will see it puff out along with the air … so in that sense it acts as a warning that the dryer needs some attention (though another implication is that a sub-functioning dryer is not a huge fix-it-immediately problem …. Just purge the tanks on a daily basis until you can get into the shop.

Does that make sense?

[Iceclimber]

I got my hands on a diagram from Roadmaster, you will never guess where....a post here from a few years back. My system has air two valves in the back engine compartment, and the air dryer that is set up to auto purge so according to this info, there is no moisture to drain. I will get under there later and find the air dryer..and hopefully the right part number.

[Ray,IN]

This pdf pertains to a Spartan chassis, however it applies to all vehicle with a compressed air system: https://www.entegracoachforum.com/in...a=media;in=273


iceclimber, yes your air tanks should be manually drained monthly,for daily used trucks they are manually drained daily. You are correct, you should not find moisture when pulling a drain cable, IF the air dryer is functioning as designed.
Most diesel pushers have automatic moisture drains, powered by 12VDC, and on the side of the automatic drain is a manual drain with a small cable running to the frame near a front wheel usually.
Both the automatic and manual drains are installed for a valid reason, not just to waste money on installing a useless item.
If you get moisture in your air brake chambers during freezing weather you might find yourself without brakes.

[Piros1]

As a word of caution I own a fleet of trucks, many of them have air brakes. Our fleet mechanic has found a couple of times where the air dryer filter failed internally and the media got into the system causing obstructed air flow. It was a real hassle to flush out. My point is don’t wait to long to change your filter. Every 2-3 years as suggested not a bad idea. I change mine every couple of years. In some cases on our trucks we change out the whole unit. Sometimes easier.

[Ken Thompson]

Originally Posted by Iceclimber

Here is the picture that failed to attach....and it's sideways.

The tank on the top of the picture is the hydraulic res. for the side radiator.

[SurfsideGolfer]

On my Monaco, the decadent filter is “behind” the oil cooler just behind left rear wheel. If I purge it and get any water, I change it, as the filter contents will rot, and stop up the air lines, making a really expensive repair. Just change the filter every year and you’re good. It’s $45 on Amazon. My maintenance chart that came with the coach states,”the air system left Unserviced will be the most expensive repair you will ever have”. My coach is seventeen years old, and I will service it routinely.

[LargeMarge]

Originally Posted by hypoxia

Every 2-3 years [according to] the Monaco manual...

.
In what climate?
In what humidity?
At what elevation?
How many hours of operation?
.
Eugene, Oregon.
1996 Ford CF8000 ExpeditionVehicle.
Cummins 505ci/8.3-liters (litres).
We are between the ocean and the Cascade Range... in the swamp, and usually in the rain or fog.
.
I swap the air-dryer element annually, and sometimes it needs it earlier.
I sometimes let the housing go a decade, but sometimes it needs replacing at six years or eight.
The pop-off gets swapped simultaneous with the element.
.
.
An aside:
I mentioned Eugene, Oregon.
Draining the air-tanks down to zero often produces a few cups of fuzzy muck, irregardless of element age.
Such are the hazards of living in a swamp.
.
2003-05, we did South America twenty-four thousand miles.
We carried three spare air-dryer elements and an impact-driver to bust the screws.
Draining the air-tanks throughout our twenty-four month trip, we never saw one drop of liquid.

[LargeMarge]

Originally Posted by MN_Traveler

The lanyards are attached to valves in the bottom of the air tanks...pull them, the valves open and purge air out of the tanks. They...expel any water from the tanks...I think the guidance for truckers is...this is done...daily...?...if the dryer is working...there will be no water in the tanks...if the dryer is not...functional, you will see [moisture or liquid] puff out along with the air … so...it acts as a warning...the dryer needs...attention (though another implication is...a sub-functioning dryer is not a...fix-it-immediately problem …. Just purge the tanks...daily...until you...get into the shop.

Does that make sense?

.
We purge all our air-tanks to zero at the close of each driving day:
* What are the chances of moisture in the air-lines encountering freezing conditions?
* What are the chances of moisture in the chambers or foot-treadle components encountering freezing conditions?
Moisture left in the system over-night is probably a bad idea... for us.
.
Another issue with moisture in the air-tanks:
* usable air volume is reduced by that amount of liquid.
The difference may seem minor, until the tragic intersection of pressure required but pressure not available.

[thegats1]

My coach is a 2019 model. Bought it new in 2020. Never had any moisture come out of tanks (none visible). My manual says to replace desiccant cartridge every 36 months. The cheapest I can find the Parker/Racor kit is $330 from Tiffin. I sure wish they would have chosen something easier and cheaper to change. Needless to say, I won't change it earlier than 36 months at that price. I'm considering a total replacement with a better alternative. I do most of my own maintenance, but I will leave this one to an experienced mechanic.