Dumping Air Bags When Coupling/Uncoupling

I've dropped 4 airbags, although one says she dropped me.

 

When dropping, I crank the landing gear to 1" or so above the ground and dump the tractor bags before I start to pull forward. I always dump the tractor bags whether the trailer is loaded or empty. I never bother to pull forward a bit before I dump the bags and I've never had an issue with doing so. But not all fifth wheels are the same so YMMV as far as that goes.

When hooking, I pretty much always dump the tractor bags before I back under the trailer. Once the fifth wheel is under the nose I stop, flip the dump switch off, wait a few seconds for the bags to come up, then back until the fifth wheel locks on the king pin. The only time I don't dump the bags before backing under the trailer is when the trailer is sitting so high that dumping the bags would allow me to back under the trailer without the back part of the fifth wheel contacting the trailer.

Pretty much all of the trailers I pull dump the bags when you pull the red knob so the trailer bags aren't really an issue as far as hooking/unhooking.

 

Probably been written already, dropping a trailer, I touch the pads to the ground, disconnect, pull forward a skoetch then dump air.
Hooking up, judge the height of the trailer and decided if I need to dump which is usually Yes because someone did not lower the landing gear all the way before. But I don't want to scrape off all my grease so use the edge of the 5th wheel to edge of trailer and air the bags back up, step out and lower the landing gear then dump air and back close to the kingpin and air back up saving my grease.

 

I finished truck driving school a few weeks ago, and I've been looking for work since then, which I think I found but I am concerned about coupling. Really, it's stupid, I've coupled and uncoupled like a hundred times, but for whatever reason I feel I have this brain fart that I can't remember when to dump the air bags in the truck. Just need a memory refresh (or maybe it'll come back to me once I am in a truck doing it).

We were taught to do it exactly the same way as this. What is your procedure concerning air bags in a truck and coupling to a trailer? (The opposite of what you wrote). From what I remember, when we felt resistance of the fifth wheel with the trailer, we dropped the air bags, backed further, raised the air bags and then connected to the kingpin?

Thanks a bunch!

 

If you do a lot of drop an hook, if you don't drop your air bags then pretty soon you will need to add grease to the 5th wheel. This is one reason why I always drop air bags before backing under a new trailer. Ever see the front edge of those trailers, all that grease on the front edge?

Another reason for dropping the air bags, backing just before you get to the kingpin, then inflating the air bags to raise the 5th wheel, is that it will take stress off the landing gear. If you back under a trailer but don't raise the landing gear, do the tug test, then get out and try to raise the landing gear it will be pinched and difficult to raise the landing gear. Better to get under the apron, raise the 5th wheel, raise up the landing gear by inflating the air bags, and have an easy and fast time raising the landing gear with the crank.

 

You do it when dropping a trailer. Leave your landing gear about 3/4"- 1" above the ground and then dump your air. This is basically just a trucker thing to help the next guy out. When they back under it they will pick the trailer up enough to take the pressure off the crank handle. If you drop an empty with the landing gear even and then they load the trailer they'll kill themselves with the crank handle.

The first time you back past the kingpin you'll wish you didn't drop your airbags while hooking. If you scrape grease off you'll scrape it on. Crawl under the trailer and stick your hand on the plate. You ain't hurting for grease. You'll make it okay between PM's. The only time you drop your airbags hooking is if the trailer is sitting too low. The main thing is to make sure the 5th wheel plate is flat and level against the bottom of the trailer as you approach the king pin.

 

That's why you GOAL. One will only high hook a loaded trailer so many times before they realize they should make sure the trailer isn't too high before backing all the way under it. Besides...dumping the bags when your bobtail isn't going to lower the 5th wheel hardly at all. If you were going to high hook, you would've done it regardless of whether you dumped the bags or not.

 

I avoid high hooking by first backing until the rear tires of the truck tandems are under the trailer, then getting out and look to determine the height of the trailer relative to the 5th wheel. Then dump air bags as necessary and I back until the front set of tires on the tractor tandems are getting under the trailer, then getting out and looking to make sure the kingpin is behind the locking jaws, then getting in and inflating the air bags. I then get out and make sure the 5th wheel is flush to the plate and everything is in order, then back in to lock the jaws. I then tug test and get out with a flashlight and make sure the locking jaws are in place. If everything checks out I proceed to connect the air lines and pigtail, raise the landing gear, and do my trailer pretrip inspection.