Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 12, 2025 ...

Dash Air Filter or "Dryer"?

September 09, 2015, 02:54:25 pm

I was talking this morning with an acquaintance at the park where we are staying.  We were talking about the recent service Susan & I had done on the coach (engine and generator oil, filters, etc.).  He asked if we had the dash air conditioning filter or "dryer," he called it, replaced?

He told me the story about why he was concerned:  he owned a Country Coach.  He had the coach serviced but skipped the air conditioner filter/"dryer."  It quickly failed.  Apparently it "contaminated" (his word — I'm over my head here) the rest of the dash air conditioning system and the system had to be repaired at a cost of $2,000, rather than $50-ish if he had replaced the filter.  This is a smart, mechanically-savvy guy who worked on military jet aircraft, so I trust him.  I just may not understand what he was talking about?

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Re: Dash Air Filter or "Dryer"?

Reply #1 – September 09, 2015, 03:23:19 pm

In a word, neither do I (understand what he is talking about).

Have never heard of servicing the dash A/C dryer as preventive maintenance.  I replace them when the system is opened, compressor replaced, etc.  But, I would sure not discharge, evacuate and recharge a perfectly functioning dash A/C to replace the dryer.

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Reply #2 – September 09, 2015, 05:06:46 pm

Thank you, Brett!  I'm frequently unsure about what I'm hearing, because I have so little technical background.  Our dash air seems to be functioning well.  Happy to know we haven't missed doing something important.

By the way, despite our limited technical background, we ARE trying!  <smile>  Susan & I took two weeks of training, one week in January and one in March, just in hopes of purchasing smartly.  We also have read and re-read the documentation for our coach.  And I'm reading the Foretravel Forum daily, as well as talking periodically with the previous owner and several Forum members we've met in person. 

Just don't ever want you or anyone else on the Forum who has helped us to think we're just lying in the weeds, eating chocolate and drinking beer (Ouch! What a terrible combination), while we depend on everyone else's knowledge to take care of us.  :-)  Thanks for your kindness in helping us with the learning curve.

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Reply #3 – September 09, 2015, 06:02:08 pm

Yeah. The receiver dryer is only replaced if the system is opened or serviced due to another component failing (such as a compressor grenading). Replacing one as preventive maintenance on a fully functioning system is nonsense.

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Reply #4 – September 09, 2015, 06:07:24 pm

Id also consider anyone calling themselves an aircraft mechanic a negative when receiving advice. They are mostly useless at actually troubleshooting anything and good at mindlessly replacing parts.

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Reply #5 – September 09, 2015, 06:19:26 pm

Richard and Susan
Good to hear your trying to get educated on your coach, it will serve you well.  If your not sure throw out the question, people here are very knowledgeable and willing to help.
Jerry

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Reply #6 – September 09, 2015, 06:55:28 pm

I'd suggest he sticks to airplanes--where on the big ones they have step by step procedures.

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Reply #7 – September 09, 2015, 07:05:38 pm

FYI: Today we had Thermo King in Cloverdale, VA repair a A/C leak under the dash. We're on a trip north. They took us in right away. Found the leak with nitrogen right away. Replaced a fitting right away and off we went, Amazing service! Know their stuff.
Unfortunately, in May FoT did not look for a leak. Just topped it up with "Freon".

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Reply #8 – September 09, 2015, 07:23:50 pm

Richard, I myself find nothing wrong with a good beer and chocolate!
 You don't want to do a 3 musketeers and beer though, that combo foams up in your mouth😀

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Reply #9 – September 09, 2015, 09:42:18 pm

He's probably talking about the air dryer on the air brakes. I often find that people think I'm talking about my air conditioning when I talk about my air brakes.

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Reply #10 – September 09, 2015, 11:30:11 pm

"military jet aircraft, so I trust him.  I just may not understand what he was talking about"

Most all "jet" aircraft I worked did not have a "receiver/dryer"
The used a turbine system (for compression) and an orfice for expantion to get cool air.
The 1st 707's used a freon system through.

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Reply #11 – September 10, 2015, 07:55:27 am

Hi LookingWest

If you would like some information on how an automotive AC system works, here is a link
http://www.rdac.com/sites/default/files/How%20HVAC%20Works.pdf
It is a very basic but good explanation on how it works

Here is a check list that we use at work.  Now keep in mind that this list is for and Over The Road Truck (OTR) that puts on thousands of miles a month
http://www.rdac.com/sites/default/files/Preventive%20Maintenance%20Product%20Sheet.pdf

Note that they recommend that you change your receiver drier once a year.  We don't do that.
But on our systems there is a small sight glass on the drier that will change colour if it gets water or contaminated, then we will change it out.

But a good technician with a set of gauges hitched up to your dash AC system can tell quite alot.

I have just joined this forum and will start to contribute when I can.

Hope this help.

Brian

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Reply #12 – September 10, 2015, 10:18:12 am

Wow!  Big thanks to so many of you for great information.  Green99, thanks for the encouragement.

Brian, welcome to the Forum, though I'm certainly not the most experienced or longstanding voice in this thread.  I really appreciate the links.  Susan & I will study those carefully (she's an engineer's daughter, so she is as interested in all this as I am!).

Bill, Scott, car54, and krush — understand.  Perhaps I should have said, "having work on military jet aircraft, he's more mechanical than I am."  <smile>  But I'm learning not to instantly trust everything I hear.  ;-)

dougself, thanks for the good referral.  We pass through VA several times a year, so that's good to know.

And rbark, you're probably right. Some of my craft-beer friends are even brewing beer that has hints of chocolate on the palate!  But I'll be SURE to stay away from 3 Musketeers with our favorite brew!  <big smile>

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Reply #13 – September 10, 2015, 02:48:55 pm

Richard.
You are most welcome.
If you really want to get technical, here is a link to a Red Dot service manual.  So on those nights that you cant sleep, just pick a copy of this up and have a look.

http://www.rdac.com/sites/default/files/Service%20Manual%202_0.pdf

This is one of my "Bibles" at work.  I have a herd of young apprentice mechanics that just love any kind of information I can throw at them.  I probably print 3 to 4 of these off a year and pass them out.  (These guys are like a sponge in water, their hungry little minds just soak up what ever I can throw at them.  Keeps me on my toes)
While I am comfortable working on AC, it is not my favourite thing, I have managed to get several of the lads trained up to the point that I can just give it all to them now and not worry about it.

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