Forum Discussion

JKJavelin's avatar
JKJavelin
Explorer III
Dec 13, 2019

TrailAir Pinbox Observation

TrailAir owners:Just before a 2300 mile trip this fall I installed a TrailAir pinbox on my Open Range. I settled on 55-60 psi for the bladder and enjoyed watching the trailer float behind me. I noticed that when I accelerated from a stop that I could see the shock absorber compress (and then float) and when I stopped I could see the shock absorber extend fully.
Several times over the summer I found that during hard braking that the trailer would sometimes skid. Towards the end of our fall trip I decided to back off the RAM brake controller one notch (from about 6.0 down to 5.5). After doing that I could see a change, that the shock absorber no longer extended during braking. Instead it pretty much stayed at the same point as cruising. I am guessing that this is a sign that the trailer brakes are at the correct level relative to the truck brakes.
Opinions?
JK
  • eHoefler's avatar
    eHoefler
    Explorer II
    Dec 14, 2019
    The level is not set by air pressure, you need to add air until the colar on the upper part of the shock is at the point of the arrow on the lower body of the shock
  • Campinghoss's avatar
    Campinghoss
    Explorer II
    Dec 14, 2019
    I do not use the arrows on the trail air to set the bladder. I have found that keeping the bladder just below the arrows gives me a much better ride and also keeps the fiver almost level. In other words how much pressure I put in the bladder is dictated by the ride. I have my gain set so at 25 mph and I manually engage the controller my fivers will slow the truck but not lock up.
  • Cummins12V98's avatar
    Cummins12V98
    Explorer III
    Dec 14, 2019
    What you are saying tells me you "had" the braking on the RV set too aggressive.
  • JKJavelin's avatar
    JKJavelin
    Explorer III
    Dec 14, 2019
    Cummins12V98 wrote:
    What you are saying tells me you "had" the braking on the RV set too aggressive.

    That's what I was thinking. Many of us are guessing when adjusting trailer brake force....at least I was. With the TrailAir you can "see" the braking inertia of the trailer. It appears that when the shock absorber remains neutral, it is neither pulling nor pushing on the truck.
    JK
  • Slownsy's avatar
    Slownsy
    Explorer
    Dec 14, 2019
    If it isn’t pulling on the truck what is propelling in forward has it got its own engine?
    Frank
  • JKJavelin's avatar
    JKJavelin
    Explorer III
    Dec 14, 2019
    Slownsy wrote:
    If it isn’t pulling on the truck what is propelling in forward has it got its own engine?
    Frank

    Sorry Frank, I was referring to pushing/pulling during braking.
  • Veebyes's avatar
    Veebyes
    Explorer II
    Dec 15, 2019
    Having the right sized bladder makes a difference all round. Once had a heavy trailer that required the bladder pressure to be about 100psi to be on the line. Trailer rode stiff. Called TrailAire & they sent a bigger bladder, no charge.

    Much better. Only needed about 50 psi? to be on the line. Wonderful! Wish the current trailer had the TrailAire. It came with a 5th Airborne pinbox. Nowhere near the travel distance or ride of the TrailAire. Only good thing about the 5th Airborne is that the bladder is not exposed to the sun.
  • justme's avatar
    justme
    Explorer
    Dec 17, 2019
    Beware that the "arrow" indicator sticker on the shock is evidently added by the installer/improperly by the mfg sometimes incorrectly. When they installed my TrailAir someone misapplied the arrow and it was to high and required to fill the bladder completely to reach the arrow tip. Consequently I marked the shock with no air.-- then half way and finally when the bladder was full ( fully extended shock). I found the trailer travels the best when between 1/2 AND 3/4 extened at the shock. At the point there is minimal chucking and better ride..... Mine rides with 70-80 PSI with a pin weight of 3100lbs.
  • Cummins12V98's avatar
    Cummins12V98
    Explorer III
    Dec 17, 2019
    justme wrote:
    Beware that the "arrow" indicator sticker on the shock is evidently added by the installer/improperly by the mfg sometimes incorrectly. When they installed my TrailAir someone misapplied the arrow and it was to high and required to fill the bladder completely to reach the arrow tip. Consequently I marked the shock with no air.-- then half way and finally when the bladder was full ( fully extended shock). I found the trailer travels the best when between 1/2 AND 3/4 extened at the shock. At the point there is minimal chucking and better ride..... Mine rides with 70-80 PSI with a pin weight of 3100lbs.


    Good info!
  • JKJavelin's avatar
    JKJavelin
    Explorer III
    Dec 17, 2019
    justme wrote:
    Beware that the "arrow" indicator sticker on the shock is evidently added by the installer/improperly by the mfg sometimes incorrectly. When they installed my TrailAir someone misapplied the arrow and it was to high and required to fill the bladder completely to reach the arrow tip. Consequently I marked the shock with no air.-- then half way and finally when the bladder was full ( fully extended shock). I found the trailer travels the best when between 1/2 AND 3/4 extened at the shock. At the point there is minimal chucking and better ride..... Mine rides with 70-80 PSI with a pin weight of 3100lbs.

    Yes, I inflate mine to the high side of mid stroke and have marked mine with colored tape.
    When I received my pinbox I saw right away that there was no yellow sticker on the shock absorber and looking closer I could see the arrow was stamped (engraved) into the shock and of course painted black...impossible to see. I called Lippert and asked them for a sticker with the arrow and was told that the sticker wasn't available separately and they would send me the whole shock absorber. Well, I got the new shock 2 days later and guess what? No sticker either!

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