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lakebum's avatar
lakebum
Explorer
Jul 05, 2016

Air Brakes - Alarm HELP

Just go back from a 1200+ mile trip on our still new to us Coachman. We have a Freightliner chases and it is equipped with air brakes, air bag ride and while traveling for no apparent reason the #1 tank gauge dropped to ZERO PSI and #2 Tank stayed at the 125# PSI or somewhat close.

Could not discover any reason for the alarm to sound, still had brakes and air pressure and the audible alarm and zero gauge reading would last for anywhere from 30 seconds to 10 minutes and then the gauge would jump back to the normal setting and alarm go off.

This seemed to happen almost 1 hour into each start up and would last for 30 minutes or so and then just stop as quick as it started.

It happened normally while cruise was set and didn't matter if it was smooth or rough interstate, not braking or using any air.

Any ideas on how to troubleshoot?
Class A

10 Replies

  • lakebum's avatar
    lakebum
    Explorer
    Jul 07, 2016
    Here was the VERY quick response from Freightliner, by the way, I called and held for almost 20 minutes then decided to email them. I included VIN number and photos of dead gauge and almost got an instant response, less than 5 minutes.

    ______________________________________________________________________________________________

    Most likely, if you look at the back of your instruments, you will find
    WHITE lin-data jumpers that jump from gauge to gauge. If so, you would need
    to purchase the following parts and quantities from any Freightliner Dealer
    and install these new BLACK lin-data jumpers just like your current ones
    are.

    A06-69135-012-speedo (1)
    A06-69136-012-tach, volt, fuel, CT, OP (5)
    A06-69136-063-remote air gauges (1)
    POL 028A274098004-pri, sec air gauges (2)
  • lakebum's avatar
    lakebum
    Explorer
    Jul 07, 2016
    fcooper wrote:
    Call the free Freightliner Help Desk. They are really helpful, and I've used them several times. Have the last 6 digits of your vin number handy when you call. They can tell you where to start troubleshooting.

    1 800 ftl help

    Fred


    Thanks, will call them for sure, first thing tomorrow.

    Tapping the gauge does not work, I also tried cursing and stopping my feet...
  • fcooper's avatar
    fcooper
    Explorer
    Jul 07, 2016
    Call the free Freightliner Help Desk. They are really helpful, and I've used them several times. Have the last 6 digits of your vin number handy when you call. They can tell you where to start troubleshooting.

    1 800 ftl help

    Fred
  • OLYLEN's avatar
    OLYLEN
    Explorer
    Jul 07, 2016
    Air brakes to me are kinda a backward thing. If you have NO pressure the brakes will be on and you would know it, you would be stopping in a hurry. Sounds more like a loose wire to the gauge or a sensor being intermittent. dhave you noticed a bump brings the gauge back?

    LEN
  • lakebum's avatar
    lakebum
    Explorer
    Jul 06, 2016
    Kayteg1 wrote:
    If the gauge jumps from 0 to 120, it has to be electrical issue.
    The compressor takes couple of minutes to do that.


    That is what I was thinking also. No way to build 120# of pressure that fast.
  • Kayteg1's avatar
    Kayteg1
    Explorer II
    Jul 06, 2016
    If the gauge jumps from 0 to 120, it has to be electrical issue.
    The compressor takes couple of minutes to do that.
  • Papaalfa's avatar
    Papaalfa
    Explorer
    Jul 06, 2016
    I would look at the LOW PRESSURE switch-you may have one or three. They are not expensive I would replace all.
  • mabynack's avatar
    mabynack
    Explorer II
    Jul 05, 2016
    Possibly excessive condensation in the tanks. Try opening the drain and see what comes out. If air comes out of the tank when the gauge is reading zero and you don't get a lot of water, you probably have a defective pressure sensor or a grounded wire between the sensor or gauge.
  • deedle82's avatar
    deedle82
    Explorer
    Jul 05, 2016
    I just had the wiring harnessed replaced in mine a month ago, mine was low air light and buzzer was coming on but the gauges where fine, would come on 10 min into the trip or 5 hour into the trip, smooth and rough roads.
    Just got back from a month long road trip and did not come on at all. Oh Happy Day.
  • pulsar's avatar
    pulsar
    Explorer
    Jul 05, 2016
    We had a 2008 Journey with a similar problem. In our situation, both gauges would go to zero. Turned out to be the wring to the gauges. In fact, there was a freightliner service bulletin on the issue along with a better wiring harness.

    Tom

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