new reitnouer need advice.

Page 11 of the Hendrickson manual attached

 

The only trailer that we have that has a dump valve is the Chaparral 4 axle. This is due to the bleed down of the bags causing the trailer to push forward on the landing gear and folding it up twice, or so I have been told. Also works well to dump the air when you are unloading that single piece that weighs 60k or better so as to not over stretch the airbags because they cannot dump air fast enough.

Well, I forgot that all the RGNs have a dump valve also for the same reason.

I would not want a dump valve for a single axle for one simple reason. Taking 40k and putting it all on a single 23k axle is not good for anything. Especially if you have a good portion of weight behind the front axle and you dump the rear. Nothing to support the last 10-12 feet of the trailer and load.

I have not had a problem putting a trailer where it needed to go. If I have to make extra pull ups then so be it. I also will not make a turn where the tires are not rolling like I see often at truck stops. I make my turns wider than most for that reason. In tight situations I just jockey it around until I get it in place.

 

Rank, the parts in those parts referencing manufactures are talking about using a dump valve at traveling speeds. no one is suggesting you use a dump valve at 30mph. In fact, it's not even legal to do that. Dump valves are for low speed maneuvers.

 

Page 11 of the Hendrickson link:
"Hendrickson approves the use of dump valves ONLY when they exhaust the air from ALL the air springs.....or else you must get written approval from Hendrickson Engineering Dept."

Page 3-12 of the Wilson Link:
IMPORTANT
Do not raise liftable suspensions on loaded trailers, even for low speed maneuvering"

CAUTION
"Operating this trailer under loaded conditions with the lift axle up may result in damage to the trailer"


I didn't read anything about a speed limit making it OK.

 

I was responding to the link you posted above from the classadrivers forum.

As far as the Wilson manual you posted. That's for a grain trailer, with a lift axle. an entirely different animal than the topic of a spread axle flat bed. the phrase "does not apply" comes to mind.

The hendrickson link is confusing because my flat, with a hendrickson suspension, came from the factory, with a factory installed rear axle dump. In direct conflict with what your link states. So that leads me to believe that the page you linked is for a different suspension, or a different application.

 

Hokey Dokey then.

I'm not exactly sure how a grain trailer would be a different animal in respect to rear axle dumps but it doesn't matter.

I think I have done about all I can do here. I have posted links to Henrickson, Spicer and Wilson literature and I have posted my own first hand experience in trying to order a rear axle dump from Wilson. The phrase "lead a horse to water" comes to mind however I respect your opinon Spyder so I'll give you the benefit.

Perhaps you can post the build sheet for your trailer that shows your rear axle dump was factory and not a post production add on by dealer or owner?

 

Question rank. That Wilson grain trailer a spread axle? the images in the docs was a tandem with a third lift axle.

 

Dunno Spyder it's not my trailer. I just googled for a manual and that came up. I could check my manuals tomorrow. They are all spread axle steps.

 

I was asking cause that makes a huge difference in the suspension. That's what I meant by different animals. Spread vs tandem, and lift axle vs dump valve. the axle itself is probably identical, but some of the suspension parts and how they mount to the frame will be different.

 

As promised, pic from the manual of a 2015 Wilson Roadbrute, 53 ft combo, sliding rear axle, 124" spread when opened