Forum Discussion

et2's avatar
et2
Explorer
May 31, 2014

Air system maintenance

Well I finally got around to trying to pull the lanyards on the air tank automatic moister ejectors. I understand they are automatic but the owners manual states to pull them every 6 months no matter what just in case they aren't working properly.

There are three on ours. Two behind the passenger front wheel and one behind the drivers front wheel. They come thru the frame. I could just barely reach the two on the passenger side. The front worked fine and released the air. The rear did not. It barely released air no matter how hard or light I pulled. Definitely there was something wrong with it. So I assume it is still under our 1 year warranty. The one on the driver side I couldn't even reach without crawling underneath. So not sure about that one.

We dropped it off at a local Freightliner repair facility to have it looked at along with a few other things pertaining to them. I was surprised they don't set appointments, it was a first come first serve. But there was at least a week wait. Wasn't crazy about the MH sitting there all week.

So my post is just a reminder that some maintenance things which might get ignored shouldn't be. I wonder if the the one bad ejector has malfunctioned allowing water into the braking system. That could be a big problem somewhere down the road.

Now all I need to do is find something to allow me to pull the other lanyard without crawling under the coach.

7 Replies

  • Gasman 2 wrote:
    Did you have the air system completely air up when you pulled the lanyards. Possible all tanks were not aired up. I don't think the auto mositure ejector is part of the tank drain valve but is the air dyer completely different than tank drain valves. Like Brett said the drain valves are report card on the air dyer to see it's doing its job.


    I made sure the tanks blew off so they were full with the engine running. One had no issue. The other had a problem.

    Here is what is stated.

    Freightliner chassis are equipped, as standard equipment, with a heated automatic moisture ejector on the wet tank in addition to one built into the air dryer. This eliminates the need to climb under the coach to drain air and water from the tanks daily. You still must pull all three drain lanyards for 10 to 15 seconds every 6 months to drain moisture. A fine mist is normal due to condensation. If a large amount of moisture is present it should be completely drained and the air dryer serviced. Moisture in the braking system can cause brake system failure and is not covered by the manufacturer warranty.


    The lanyards are attached to these ejectors / dryer. So as I found out one is not allowing air out as it should, meaning there is probably a problem with the ejector/ dryer.
  • Did you have the air system completely air up when you pulled the lanyards. Possible all tanks were not aired up. I don't think the auto mositure ejector is part of the tank drain valve but is the air dyer completely different than tank drain valves. Like Brett said the drain valves are report card on the air dyer to see it's doing its job.
  • BTW, on any air system with an air dryer (the VAST majority of coaches) the drains are really a report card on the condition of the air dryer.

    If anything ever comes out except clean dry air, your dryer has FAILED. Water, dirt or white powder are all signs of a failed dryer.

    Regular PM on the dryer will prevent this from happening.
  • I use a awing hook,( the type used on manual awnings ) works great there is a loop at the end of the lanyard
  • Ranger Smith wrote:
    I have to crawl under mine to pull the lanyards too. What year is your rig and did you have the air dryer serviced with new filters in that.


    It's a Fleetwood Expedition 40x - purchased end of July 2013. It's a 3 year schedule to replace those. So I still technically have two more years before service was (is) needed.

    Unless of course something shows in error. Like what is going on with the pressure release lanyard, or pressure loss or braking issues.

    I'm not as nimble or slender as I used to be. Crawling under the coach is something I'm not crazy about doing unless it's supported on jack stands. I'm the guy someone will find with their feet hanging out from underneath after the coach came down on me? :E
  • I have to crawl under mine to pull the lanyards too. What year is your rig and did you have the air dryer serviced with new filters in that.