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Air guages have two readings

2001 U320- 40' single drive axle, IFS. The two air guages on dash always read different pressures. One stays around 80-90 and the other is around 100lbs. Foretravel says there is nothing wrong. I still question why the different readings? Could one of the guages be faulty? Or is the reserve/pressure in one tank less than the other?

Any help would be appreciated.

Thanks,

David
David West
2001 U320 40'

Re: Air guages have two readings

Reply #1 –
One is reading the front air tank and the other is reading the rear air tank.
1994 U225
build #4514

Re: Air guages have two readings

Reply #2 –
Quote from: dwest –
2001 U320- 40' single drive axle, IFS. The two air guages on dash always read different pressures. One stays around 80-90 and the other is around 100lbs. Foretravel says there is nothing wrong. I still question why the different readings? Could one of the guages be faulty? Or is the reserve/pressure in one tank less than the other?

Any help would be appreciated.

Thanks,

David
Are they different when the engine is running? Should be about the same being fed directly from the wet tank to Front and rear air tanks. Have you tried to reverse the gauges to see if you get the same readings?
The selected media item is not currently available.Barry BEAM #16014
2003 U320 40' AGDS
Beamalarm, Foretravel technical help and specifications
"Whatever the mind can conceive and believe, it can achieve"

Re: Air guages have two readings

Reply #3 –
Hi David,

I had the same question a few years ago so I had tech Bob at FOT make them even. It was odd to always see them uneven. Not that it makes any difference what so ever - I think he merely adjusted something forabout 20 minutes to make me happy. He made no changes to the gauges.
Jim Frerichs
2002 U320 42'

Re: Air guages have two readings

Reply #4 –
Great info, so on my 95 U300 which needle is front air tank, Red or White..???

Hans
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Air guages have two readings

Reply #5 –
Look close, they should be marked P. &  S. as in primary & secondary.

Re: Air guages have two readings

Reply #6 –
This is a issue with 2001. They do not make the gauges any longer and they are electrical. You can not just remove them or you get the level light so I tee off the tanks and put in VDO mechanical gauges in their place. Now i have the right reading.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Air guages have two readings

Reply #7 –
Quote from: Dave M –
Look close, they should be marked P. &  S. as in primary & secondary.

Primary, Front..??
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Air guages have two readings

Reply #8 –
I got two mechanical gauges in the the dash to replace the two electrical gauges that were no longer available (one had gone "bad").  Mine read within a psi or two of each other.

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

Re: Air guages have two readings

Reply #9 –
Mike and John;

I like the idea of replacing because it drives me a little crazy as well.

Where did you guys get the guages? Made by Stewart Warner? 
Mike I did not understand what you meant by t-off?

Thanks,

David
David West
2001 U320 40'

Re: Air guages have two readings

Reply #10 –
John wrote you about the t-off but I am going to guess that he is saying off of the line from the tanks?

As for mine, we could not replace the Stewart Warner electrical gauge so MOT got a mechanical one.  That they would match gauges in the dash, they just did both with mechanical.  One difference is that I can read the gauges while parked at a site and not turn on the key.

Interesting is that in chasing down leaks we parked for nearly two weeks and the psi only declined about 70 psi while parked.  In the past I could go to almost a 110 psi decline in four days.  This in some part I am sure was due to replacing the air activated fold down step which (those) has a reputation of leaking cylinders.

Hope this helps you,    Mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Air guages have two readings

Reply #11 –
Quote from: sfbmw –
Primary, Front..??
Like our cars, our motorhomes have Dual Air Brake System, which consists of two separate air brake systems that use a single set of brake controls. It is designed to retain braking ability in the event one system fails.  Thus one is primary and one is secondary.  Doesn't really matter where they are at.  Usually three all together.  One primary, one secondary, and one wet.
Air Brakes 101
1994 U225
build #4514

Re: Air guages have two readings

Reply #12 –
Thanks Pat, so the red and white needles represent Primary and Secondary, still not sure which is which red/white needle.??

Sorry for the lack of brain power here.. ;D

Hans
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Air guages have two readings

Reply #13 –
I'll bet white is primary and Red is secondary.  Red meaning warning.
1994 U225
build #4514

Re: Air guages have two readings

Reply #14 –
Pat, makes sense red being a warning color.

Thanks Again

Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Air guages have two readings

Reply #15 –
93 u300
red is for rear systems ( brakes etc )  ( also right tank in front )
white is for every thing else.
1993 U300, 6v92
build 4366
USAF retired, Flight Engineer, C124, C130
 ATP, A & E.  & ex AI

Re: Air guages have two readings

Reply #16 –
Thanks Bill.!
Hans & Marjet
1995 U300 "Ben" (#4719)
3176B Cat,4060HD,Jake
SKP#139131
Motorcade#17579
2006 Honda Element (towed)

Re: Air guages have two readings

Reply #17 –
Mike,

I am going to MOT at end of the month anyway. I will call ahead and see if they keep guages in stock.

Thanks,


David
David West
2001 U320 40'

Re: Air guages have two readings

Reply #18 –
David, was out at MOT to see progress on our annual maintenance and getting the MCD shades.

I talked to Allen in Parts and he said that if you would call in advance he would have the gauges when you arrive.  He said that they are getting commonly desired sufficiently now that he should be stocking them, and will do so. 

But I think please call him first if you would be on a tight schedule, not want to rely upon getting them sent to MOT while you waited a day or so?

You can read Allen (MOT) 936-564-1112

If you want photos of how they look, let me know.  I think fine, but this adds two silverish bezels to an other wise black dash (SW gauges)

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