I am relatively new to the HGV industry and work for an AFP thar use single and double deck box trailers.
My question is how do you check that the self levelling is working correctly?
The reason I ask is that one of our drivers was pulled over for a DVSA inspection which resulted in a prohibition notice. This was due to the trailer not self levelling. They advised the driver that the rule of thumb is that you should see 2 - 3 inches of the pedestal below the airbag.
Now I had a newish twin axle box trailer the other night that had the airbag at a height of 6-7 inches. To raise and lower the trailer you had push buttons(no handle) at the rear near side of the trailer. So I dropped the trailer down so I could see 3 inches of the pedestal. After a few minutes of driving I checked the airbag and it returned back to previous height showing 6-7 inches of the pedestal.
I want to know is this rule of thumb correct for all trailers or did I have a faulty trailer or issue with the self levelling.
Does the A in AFP stand for Amazon?
AFAIK the single deck push button trailers are self leveling, like you experienced.
I don’t see how the DVSA can be issuing prohibition notices on the strength of a rule of thumb? [emoji2962]
Some I’ve worked have a leveler inside the trailer,
I think they use it mostly when the trailer is getting loaded and sometimes they forget to reset it
This was one with a built in tail lift
stu675:
I don’t see how the DVSA can be issuing prohibition notices on the strength of a rule of thumb? [emoji2962]
That’s my point exactly which is why I’m here for clarification.
If self levelling does not work would it just inflate the airbag to full? I’ve tried googling it but it mainly comes up with self levelling floor compound.
In hindsight perhaps I should have tried to raise the trailer to see if it would lift any higher than the 7 inches it was currently at.
I’d hate to refuse a load when the trailer is behaving normally but then I’d also wouldn’t want to take a non self levelling trailer on the roads.
So, it isn`t your trailer?
What does it say in your contract with trailer owner? Who has responsibility for what?
The prohibition notice requires that the trailer be presented for test?
If it was my own trailer I would present it immediately, without any work being done.
If its good, then the notice was given wrongly and should be contested. If there is a fault, youll see what it was and so learn to look out for it.
If its not your trailer then its time to have “an involved discussion” with the owner.
stu675:
I don’t see how the DVSA can be issuing prohibition notices on the strength of a rule of thumb? [emoji2962]
That’s my point exactly which is why I’m here for clarification.
If self levelling does not work would it just inflate the airbag to full? I’ve tried googling it but it mainly comes up with self levelling floor compound.
It’ll either go full height or end up on it’s arse. Either result is plainly obvious when looking at the airbags. And whilst you won’t feel it when it’s fully up, when the air suspension on the trailer is lowered fully it feels terrible, you can feel the trailer bouncing and you will feel a slight rocking forwards/backwards when it goes over bigger bumps - it just doesn’t feel right.
stu675:
Does the A in AFP stand for Amazon?
AFAIK the single deck push button trailers are self leveling, like you experienced.
I don’t see how the DVSA can be issuing prohibition notices on the strength of a rule of thumb? [emoji2962]
Nor do I. Many different air bags. Lots of trailers out there running around with spurious air bags on either axle giving different pedestal measurements yet sitting at ride height perfectly well. Not ideal but never seen a prohibition issued. Learn something knew every day lol
stu675:
I don’t see how the DVSA can be issuing prohibition notices on the strength of a rule of thumb? [emoji2962]
That’s my point exactly which is why I’m here for clarification.
If self levelling does not work would it just inflate the airbag to full? I’ve tried googling it but it mainly comes up with self levelling floor compound.
It’ll either go full height or end up on it’s arse. Either result is plainly obvious when looking at the airbags. And whilst you won’t feel it when it’s fully up, when the air suspension on the trailer is lowered fully it feels terrible, you can feel the trailer bouncing and you will feel a slight rocking forwards/backwards when it goes over bigger bumps - it just doesn’t feel right.
Amazons trailers all self level from your EBS cable, so as long as your EBS/ABS is working it should self level after going 5mph. If it doesn’t self level then your EBS cable is faulty or your trailer is faulty. There is no handle like other trailers to reset the suspension.
I had another encounter with a similar trailer last night. I dropped the suspension down to 3 inches and it lifted to double that after a few minutes driving.
Below are photos of the airbags of the trailer last night.
Collected trailer at bay and this was the airbag height
Joske:
I dropped the suspension down to 3 inches and it lifted to double that after a few minutes driving.
Then the self-leveling is working.
Any problem is that the level the trailer is set to level at may be believed to be incorrect.
Somewhere the factory will have specced the ride height tolerances, and the type approval will have that noted.
Some trailers might have that on a plate. It does affect the braking efficiency because of differing weights on the axles, and so is rightly a concern for safety.
I`ll let those who know more than me, expand on that, or shoot me down!
Since you aren`t the owner of the trailer, good luck with all of that.
