Do you dump the bags everytime when pulling out from under a trailer?

I really don't see that happening unless you have mechanical problems. If your gear is evenly touching the ground the trailer won't bang the support brace. That usually happens when a driver leaves his landing gear about an inch above the ground and forgets to dump his air. Either that or you were on uneven or soft ground which you would of known, like the truck drives sitting in a pot hole or recess.

This is what I think happened if it wasn't the terrain... you have a defective 4-way valve sticking which divides the air to the brake system and the air suspension system. You popped the brakes and the bags deflated on you. You lowered the gear until it touched. You got back in the truck and released the brakes and the air bags inflated again. Hence raising the gear back off the ground. Next time you drop a trailer push the buttons in and out and watch your landing gear and see if the height changes. Then write the truck up.

But what every one said is good info. Then when the next driver hooks the landing gear will raise off the ground releasing the handle cranking pressure. I think we all had to fight an old trailer that was dropped improperly. It can be a booger.

 

Haha! The OP just found the safety catch

 

Except for a hydraulic rgn.

 

At least you had a solid landing for that bang you heard..I seen a driver do the same thing as you except one of his landing gear legs collasped because of the force of the wieght and he put the trailer on its side,,

 

Cascadia's are real bad about popping the frame when ya unhook too. As stated lower the gear until you start to hear air bleed off ease out slowly and never had a problem unhooking on any terrain. Hooking up to a 45000 lbs meat load that was dropped in the mud is a different matter

 

heck if it wont....take a trailer that is nose heavy put the gear down and pull out. the truck will pop up and the trailer nose will drop like a rock and meet in the middle...dump the junk save the truck

 

And it was swingin' John Anderson, Just use your judgment. Concrete is a good surface to park on. A rail refer is made light and not made to be left loaded for hours.

 

that's why you know your truck you back uner just enough to get the plate under the trailer than air the bags up and once the air up all the way you back under the rest of the way.....however you could still go under a king pin id say you run lp 22.5 on a pete and the guy that dropped the trailer was running 11r24.5 on a freightliner with a high set 5th wheel...so yea that goal???? would be YOUR best bet...me I just know my rig and what things look like when right and wrong...

 

how can you know your rig.

like you said. one guy had 24 tires. and your truck has 22. that trailer is gonna sit high for you but normal for him.

if you dropped then it would be low for him.

you don't know what dropped it last.

 

I can get a good idea by looking in the mirror at the gap between the trailer plate and my drives as I back under. And if that gap didn't grow while backing under or inflating bags once under, I goal