How in the heck do I stop the bags from dumping

Don't set the trailer brakes. It say's right on the button "NOT FOR PARKING"

 

Your trailers are setup for an auto dump on the supply, usually there was is a manual dump on there as well in a box or back by the air tank. Be a little lever marked fill/dump. Dump the air manually out of the trailer and then hit the dock. That will eliminate the "dock walk" that you're referring to. As for the trailer height at the docks being to low the only way to solve that is to set the tractor and leave the trailer aired up. The reason trailers have dump valves is to eliminate the possibility of hyper extending a bag durning unloading. You have a fast unloading product (grain hoppers) some flatbed loads, the bags may have 80lbs of air in them when loaded and only need 10lbs empty and the control valve cannot rid the extra air fast enough. Thus causing the bags to extend and blow out. Which is where the dump comes into play. Its also on trailers to prevent them from walking when parked. If air isn't dumped and the trailer is dropped the air will eventually leak away, thus moving the trailer forward a little and putting stress on the landing gear. And over time it can make them hard to turn. Those are the 2 solutions I can come up with for you leave the trailer aired up when the dock won't line up and manually dump the air before hitting the dock to prevent dock walk.

The only other way to prevent dock walk is to pull the supply push it back in quickly hit the dock and then pull the supply again to set the trailer brakes before the bags air up.

 

i kind of like the feature, and i kind of don't.

i don't use the breaks when loading. but will if it's a one peace load coming off. (example)

 

I bump the dock and set the trailer brakes, after about a minute I release trailer brakes and bump it back against the dock again and set tractor and trailer brakes.

 

I like your explanation of why they dump when the brakes are set. I've pulled trailers like that before, and it's was aggravating when loading at docks with those small folding dock plates, cause the trailer drops so low it makes it hard to load, making it necessary to leave the trailer brakes released during loading.
I never considered the overloaded air bags, and stress on the landing gear, but now that you mention it, it makes perfect sense.
Thanks driver. You just taught an old dog something he didn't already know. I always said you never stop learning in this business, and your post proves it.
Are you sure you only have one years experience? Sounds like more to me.

 

You're welcome driver. Our bull racks don't dump just automatically just have a manual dump. I've pulled a box with an auto, and flats with an auto. Personally I didn't like the auto dump. I prefer to manually dump my air but that just me. I'm sure they made auto dump valves because somewhere down the line somebody has blown bags and somebody got smart and decided to patent the idea and is now living in Tahiti lol.

And the profile is correct. Got my CDL learners in may of 2012. I learned what I have from spending hours researching and reading posts from drivers like yourself. I agree with you and my dad has said that numerous tikes that the day you quit learning is the day you need to quit driving. my dads been out here almost as long as you have. I picked up a thing or too or tried to at least. Taught him a few things too.

I believe the rookies like myself can learn a lot from the veterans out there like yourself and maybe you veterans can learn a few things from rookies like myself. that's just my belief on the matter. If it wasn't for drivers like yourself I wouldn't know what I posted. So thank you for and driver like you with your amount of experience for helping drivers like me. It's appreciated!!!

 

We have a few flatbed trailers that tried to prevent the bags over-extending by putting a strap lengthways around the shock absorber. Didn't work to well. We just ended up with the straps breaking, dangling under the trailer, and needing repaired. Next group of trailers have the auto dump. We seldom bump docks or have fast unload freight so it really shouldn't have been an issue anyways. Seems they could make the leveling valves vent a tad faster to fix the issue.