Dropping a Trailer Properly

im pretty sure the trucks i drive do not have a air dump for the suspension. they are 2007 freightliners. i work for CRST. maybe they do and i have just not located them yet but i do have the manual for the trucks so ill look through it and ill see if i can locate the switch you are referring to.

 

Never heard that term before.

Guessing it's where the trailer is too high and it doesn't latch, but instead slides over the fifth wheel. Then the fifth wheel pops back up so you can no longer pull forward, and you have to crank up the trailer crazy high to get out from under it. Then, lower it way back down so you can get under it properly.

If so, I have experienced this nighmare twice. That's more than enough to now make me always get out and check my heights before I slide under anything.

 

well i just looked through the manual and it appears the trucks DO have the switch in which you refer. i will have to try this out next time i hook up and drop a trailer to see how it works.

Air Suspension Dump Valve, Optional
The air suspension dump valve allows the air in the
vehicle air suspension to be quickly exhausted, lowering
the rear of the vehicle. This makes it easier to
connect to or disconnect from a trailer. To exhaust air
from the suspension, move the switch to LOWER.
When the switch is moved back to the normal position,
the suspension will return to the correct ride
height. A guard is positioned around the switch to
minimize accidental activation. See Fig. 2.37.
CAUTION
Never exhaust air from the suspension while
driving. When the air is exhausted, the suspension
will not absorb road shocks and could be
damaged.

 

Geeze,

now we're gonna have folks running all around with dumped bags,,,,,,,,,,,

wondering what the hell that buzzer is for !!!!!!

 

You can really feel a difference in the ride if you were to try to drive with deflated air bags. I don't know firsthand of course I *heard* that before lol.

Hi Injun, I just put that video up because there were some who were asking about it. I don't doubt Prime or maybe other companies don't want that option in their trucks.

 

im pretty sure the big warning buzzer that sounds will be a warning. if you cant figure that one out you need to shut the truck off and walk the rest of the way to your new job at mcdonalds flipping burgers. hahaha

 

My trainer had a 2010 Kenworth T2000. So he's teaching me about the dump valve trick at a DC someplace. I back the trailer, lower landing gear, release 5th wheel, glad hand, electric pigtail etc, says dump the air bags now using this switch. Cool. Now I'm all excited etc want to hook up to the big heavy full trailer and go truckin'. Simon didn't say flip the switch and refill the airbags and the thought never processed in my mind that I might need to do that (rookie alert wooop woooop [Star Trek Red Alert Sounds]).

So we're headed to the guardshack to check out and the ride is really rough. Mentor asks "what do you think you forgot to do?" You know what, I never forget that now.

Oh long story long there but I meant to say there were no buzzers nor warnings that something was amiss.

 

wow that surprises me that there is no warning buzzer or light or signal or anything. hmm maybe they dont expect people to use it.

 

Ya, I've only had two trucks that had the suspension dump. It was a nice feature to have, and was a lot easier on the trailer. The spike, trolley bar, johnson bar, whatever you may call it is nice as well. Thing is, not all companies have those either.

If you're unlucky enough to jump the pin, sometimes you can take a piece of dunnage, like a 2X4, under the rear of the fifth wheel, and tilt it up. That drops the front of it, and you may be able to drive ahead, SLOWLY, and get the kingpin back on the right side of the fifth wheel. Not a real good thing to do, but it works. Just don't jerk things around like a mad man/woman!

 

Schneider trucks have no dump valve, nor do they have trolley brakes. They DO have power windows though