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Air Tank Switch???

Today in looking at the side console in my coach, 02 295, I noticed a switch labeled "Air Tank".
Anyone know what this is for?  I know there are some tanks under the coach.  I am still searching for another leak in the system which the air compressor supplies air to.  DAN
Dan & Shirley Stansel
2002 U295 4020 AGDS Build#6054
Towing Buick Enclave & M &  G Braking
Emerald Bay, Lake Palestine, Texas
MC# 16650

Re: Air Tank Switch???

Reply #1 –
I am going to take a guess......based on MOT looking for such switch on my 2001, thinking that it was there and that I could use it in the leveling.  If it had been there, it would have been on the panel along with the retarder joy stick, being one of the rocker arm switches.

MOT intended to use it to move some air, at the time and as I understood it, from the two large air tanks under the front of the coach in to the smaller air tank under the front of the coach that the 12v auxiliary compressor was trying to keep filled for leveling.  The little compressor could not keep up (due to a check valve problem, later discovered and reported on the Forum).

NOW Dan......I wonder what the real answer will be?!!

mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Air Tank Switch???

Reply #2 –
Tks Mike:  Seems logical to me.  My compressor takes too long to fill and cut off.  Been cking for air leaks and found one at the awning regulator bowl,  but have not had time to repair yet.  I think there are more.  If this switch will move air to the tank the air compressor fills it would be a great help.  DAN
Dan & Shirley Stansel
2002 U295 4020 AGDS Build#6054
Towing Buick Enclave & M &  G Braking
Emerald Bay, Lake Palestine, Texas
MC# 16650

Re: Air Tank Switch???

Reply #3 –
Hi Dan,

The air tank switch opens a valve to allow filling the wet tank from the auxiliary compressor. Expect it to come on almost immediately. Although the auxiliary compressor is small this allows you to air up your brake tanks without running the engine.  A quieter way to leave a campsite.
Jim Frerichs
2002 U320 42'

Re: Air Tank Switch???

Reply #4 –
When air leaks are discovered are they usually easily repaired by just tightening a fitting? Or is it more complicated than that? Just a FT newbie here with more questions.
Royce & Denise, MC #17410
'01 U320 4220 ISM450 Build #5895 SOLD
Toad: '10 Honda CR-V

Travel makes one modest. You see what a tiny place you occupy in the world. - Gustave Flaubert

Re: Air Tank Switch???

Reply #5 –
Quote from: j_frerichs –
The air tank switch opens a valve to allow filling the wet tank from the auxiliary compressor. Expect it to come on almost immediately. Although the auxiliary compressor is small this allows you to air up your brake tanks without running the engine.  A quieter way to leave a campsite.

And in our '03, the solenoid valve that is controlled by the Air Tank switch is in the bay with the HWH pump.  We actually did have ours leak through - diagnosed by watching the A and B tank pressures increase on the driver info center when the aux compressor was on but the Air Tank switch was off (ignition to accessory to fire up the driver info center, but main engine not started).
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Air Tank Switch???

Reply #6 –
Hi Royce,

If you are really lucky, just tightening them might do it. However, most of us have air leaks that seemingly are pretty hard to find - in regulators, gauges, solenoids, internally in check valves, push-in air line connectors, shut-offs, abraded air lines, step cylinders, auxiliary desiccant filter, tank fittings... You name it, practically anywhere imaginable!

Make a spray bottle of very soapy water (stream not a fine spray) and crawl under the coach to squirt everything in the air system (raise and block the coach up with pipe etc. first). If you are handy, some of the replacement components might be found at Home Depot and other suppliers in order to save a few bucks.

Quote

When air leaks are discovered are they usually easily repaired by just tightening a fitting? Or is it more complicated than that? Just a FT newbie here with more questions.

Royce & Denise
Toad: '10 Honda CR-V

Dream coach: '01 - '04 U320
Jim Frerichs
2002 U320 42'

Re: Air Tank Switch???

Reply #7 –
Hi Royce,

If you are really lucky, just tightening them might do it. However, most of us have air leaks that seemingly are pretty hard to find - in regulators, gauges, solenoids, internally in check valves, push-in air line connectors, shut-offs, abraded air lines, step cylinders, auxiliary desiccant filter, tank fittings... You name it, practically anywhere imaginable!

Make a spray bottle of very soapy water (stream not a fine spray) and crawl under the coach to squirt everything in the air system (raise and block the coach up with pipe etc. first). If you are handy, some of the replacement components might be found at Home Depot and other suppliers in order to save a few bucks.
Jim Frerichs
2002 U320 42'

Re: Air Tank Switch???

Reply #8 –
Quote from: BamaFan –
When air leaks are discovered are they usually easily repaired by just tightening a fitting? Or is it more complicated than that?
Yes --- could be either. We've had some air leaks that were fixed by tightening fittings. The most recent "fixes" involved replacing three regulators, a check valve, three HWH solenoid/valves, and an air bag. Since one air bag was leaking and they all looked the same, we replaced all air bags. Coach holds air better now than any time in the three years we have owned it.

We usually let the professionals find and fix the leaks. If you are agile, you can crawl under the coach and find the leaks with some soapy water and patience. You may be able to fix many of them yourself. Be sure to set safety blocks before going under the coach. Working Safely around your Foretravel
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Air Tank Switch???

Reply #9 –
Royce, many of us have chased air leaks for quite a while....Fix is usually easy, finding them is the problem. We do very little work on our coach (many reason why) so I don't mind having someone find leaks...We are great now, but took probably 3 trips to MOT and FOT to finally fix... Spent $800.00 (some of that was parts)..I do not get under our coach...as always, FWIW...
We are only strangers until we meet; however, some of us are stranger than others

Re: Air Tank Switch???

Reply #10 –
Ah ha, the aux compressor can be used to air up the brake air tanks?  How long does that take the small aux compressor to run?  Do I recall correctly that I am to limit the running time of that little compressor?  Somehow I think I read it should not run more than about a minute at a time?  I do know that if it runs around three minutes mine gets very hot.    Is that a difference for the 2001 FT versus some other models?  Maybe a difference in models of the aux air compressor?

This thing still concerns me.  On the latest trip, it seems to come on seldom but run for a long time.  Nearly four minutes and I pull the fuse, thinking it is/was not to run so long.  It really heats, cannot hold your hand on it.

My recollection, how I came be concerned......When my aux was running summer 2012 to try to air up the brake tanks (I guess via the wet tank), -- which was happening due to failed check valve --, I am sure MOT told me to not let it try to do this, it might burn out the aux compressor.  As I remember, the brake tanks were down to 60 psi and that pressure triggered the aux compressor to come on, trying to take them to the 120 psi range and I was told to unplug the fuse.

Sorry it this off track of this thread, not wanting to start another topic and this discussion reminded me of ......is there a limit how long that aux should run?

Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Air Tank Switch???

Reply #11 –
Quote from: Michael & Jackie –

Sorry it this off track of this thread, not wanting to start another topic and this discussion reminded me of ......is there a limit how long that aux should run?


I am sure that I'm not the onlly one who came back to a coach and found the compressor running for who-knows-how-long.  It seems to be some transient issue with the shutoff valve.  I used to just pull the fuse when that happened and then reinstall it the next time I ran the coach.  It would always behave after that for another period (month, 6 months, year).  Now I put a switch in line so I don't have to pull the fuse and worry about losing it.  The Tech at R&R told me they have done a lot of those switches as it is a common issue.  He checked out my system and did not find a problem.  In fact, my coach has now sat for about 2 months and the compressor has been coming on and off periodically without a problem.  So I am sure it has ran for at least 30 minutes before without a fault.  I've used it several times to air up the front tanks which drop to 0 eventually, sitting in the garage.  No adverse effects.  To answer your last question, I would guess that mine runs 2-4 minutes when it cycles on and off properly. 
The selected media item is not currently available.Brad & Christine Slaughter
Was:  1990 U280 36'
Was:  2002 U270 36' (With a bathroom door) Build #5981
Is:  2021 Leisure Travel Van Wonder 24RL
2015 Jeep JKU, 2003 S10 QC 4x4 or 2017 C-Max
Lake Havasu City, AZ (or Gillette, WY)

Re: Air Tank Switch???

Reply #12 –
When I was at FOT last month for service they looked at my compressor and told me "let her run".
They are made to run hot.  Anyway mine will run about 8 minutes to 12 minutes before cutting off.
this occurs about every 20 hours.  DAN
Dan & Shirley Stansel
2002 U295 4020 AGDS Build#6054
Towing Buick Enclave & M &  G Braking
Emerald Bay, Lake Palestine, Texas
MC# 16650

Re: Air Tank Switch???

Reply #13 –
Oh my, thanks.....I wonder where I read or got the "not allow to run more than a minute", or why MOT thought I could ruin it if tried to fill the main tanks, with an expensive replacement.  Good to know it ok.

mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Air Tank Switch???

Reply #14 –
A simple solution for finding air leaks is to use a childs BUBBLE soap in a spray bottle ( use the stream setting ), this stuff is cheap and it works, I don't cry when I knock over the bottle and spill half of it.
Gary B

Re: Air Tank Switch???

Reply #15 –
We all have different thoughts and cures, my cure for the 12 VDC compressor running every few hours was to install a SPST switch on the B+ wire feeding the compressor, mounted where it is visable & easy to turn on/off when open the bay door under the slide.  While am on the road/using the coach, I leave it on, but then in the garage, turn it off, the slide bladder stays full and leave most of the air out of the bags so it settles on the bump stops. ''Simple is as simple does" ? Heard that some where, seems to fit  ;D
Beside, I do not have those switch choices on my side panel.

Re: Air Tank Switch???

Reply #16 –
Dan,

My DC compressor normally runs about 5 - 10 minutes and hasn't burned out yet!! I think the real worry is leakage from if the air solenoid below the compressor. In that case it may want to run forever. Not so good.
Jim Frerichs
2002 U320 42'