If you drive 200 miles, and realise you forgot to level it, does it do the trailer any harm?
As long as the kittens that live on the chassis rails, aren’t harmed, then don’t worry., Just don’t forget to pull handle out next time, as little bunnie’s WILL die.
Have you damaged the wing tops or your spine? How do you drive that far without knowing?
Sent from my iPhone using Tapatalk
If its a tag axle, theres only one way to drive it face down arse up.[emoji57] 
Sent from my SM-G950F using Tapatalk
Depends on which way up or down out of level, loaded or light-or m/t
Down,heavy loaded I think you would have noticed before 200 miles,up and heavy loaded you might have had an airbag blow at some stage,but other than that no
Sploom:
If you drive 200 miles, and realise you forgot to level it, does it do the trailer any harm?
Yep.
It’s gonna send a message via microwave satellite to a telescreen monitored by a pointy shoed holder of a ner do well degree in social sciences or some such who is going to hurl you into financial purgatory and your children into slavery.
Or it may have worn a little bit off the tyres.
Whatever, no one died and now you are that bit more of a conscious driver as a result.
Carry on.
The levelling leaver should automatically pop out and level the trailer once you go above about 10km/h so if still in after 200 mile then it’s ■■■■■■ 
Mazzer2:
The levelling leaver should automatically pop out and level the trailer once you go above about 10km/h so if still in after 200 mile then it’s [zb]
It depends on the type
A handy early warning of driving with the trailer at max height is usually the plumes of blue rubber smoke when you brake! 
Sploom:
If you drive 200 miles, and realise you forgot to level it, does it do the trailer any harm?
The trailer should automatically self level after it reaches a set speed. If it doesn’t then something isn’t working right.
Assuming a tri-axle. If the trailer is run at Max height then more weight is on the front axle. If run at Min height then most weight is on the rear axle.
(Don`t believe me? Look at the tyres next time you raise or lower a heavy trailer)
So the individual axles could easily be overloaded. Tyres on that axle could be overloaded and overheat.
There would be a tendency for the lighter loaded axles to lock up under braking, although modern anti-lock should prevent this, although that would leave the heavier loaded axles doing more work. This would mean one axles brakes could get overly hot and fade.
If running under max weight on main UK roads, then it may be no real problem. Max weight on mountain roads could be another story.
As said most/all newer trailer should return to normal ride height automatically, but older ones won`t and may not have such a good antilock brake system, this will soon show on dry roads as blue smoke, as The Maoster points out, and on wet roads as a side view of your own trailer as it overtakes you! 
Won’t do any harm but best not to make a habit of it in case you find yourself pulling a double decker one day…
All depends how old the trailer is ,a fully manual older type valve with the 2 stop positions between raise lower and normal depending on how it’s piped will stop the air to trailer brakes .
OK, thanks for all the replies, it was empty but it never popped out automatically, it was in the fully raised position, I’ll be more careful next time
The only damage you can do really running with it up is burst airbags. If that hasn’t happened, and believe me you’ll know if it has! then you’ve nothing to worry about
In my previous work we had a few cases where drivers running low riding wag’n’drag transporter drags failed to raise the suspension after they dropped it during (un)loading, loaded especially running with suspension fully lowered would knacker the air bags in short order.
So i suggest it’s a safer bet to leave it in a raised position (maybe not so good if you are only just clearing a bridge at normal height though 
) than to run with it fully dropped, though maybe that depends on design, those low riding wag’n’drags had really small air bags which presumably would get damaged when deflated over road shocks.
Probably best not to do it when pulling a decker…
Sent from my iPhone using Tapatalk
Conor:
Sploom:
If you drive 200 miles, and realise you forgot to level it, does it do the trailer any harm?The trailer should automatically self level after it reaches a set speed. If it doesn’t then something isn’t working right.
It’s wrong to assume anything that was operated manually should revert back to its normal state automatically, and no one should rely on it to happen, you wouldn’t hook up to a trailer and assume the locking lever is in the right position and the safety catch is in place, because it should do it automatically, I don’t even trust the new Merc’s and they have sensors.
A quick check when pulling off the bay to close the doors, just give the suspension valve a look.
Drove my Actros for 2 years without the axel down only loaded to 40 ton , moffett on the back better traction, if you can leave it up leave it up, saves on tyres too.