Now DVLA have sent me a licence to drive “vans” with bends in them, I just have a quick question about trailer suspensions. Am I right in thinking as long as the trailer is connected to the tractor unit, the controls in the cab will adjust the height of the trailer as well as the tractor unit? Or is there a separate switch somewhere for the trailer?
Never thought about it until I saw a sign yesterday asking drivers to drop all the air from their trailers before docking on a bay, and realised I’d never actually adjusted the height of the trailer, only the tractor unit.
Usually there is a separate lever. Most of the time it at the the n/s rear of the tralier. (Well all of the trailers I have come across it’s where I have said it is.)
The control in the cab is generally for the unit only, there’s a separate lever to adjust the trailer suspension, as said it’s usually near the rear of the trailer but the position of the lever does vary a bit.
Depending on what you are carrying, you will find its quite useful to be able to set the tractor and trailer height separately whilst tipping.
An example - I sometimes do a backload of cages of milk - personally I drop the air in the tractor unit whilst on the bay - it stops the cages rolling out the trailer due to gravity when I remove the restraint bar.
Pallets - I sometimes raise the tractor unit air as it can make wheeling them out easier and there is no risk of the other pallets moving.
Remember to check switch/lever is set to road position after tipping/loading. Most new ones will do so automatically after you reach 20-ish kph, but not all. If you run with air dumped or over pressured the axles weights will be all to ■■■■, the trailer will handle like a sack of crap, and braking will be severely compromised. You may be asked to alter trailer height to line up with a bay, or angle the trailer to assist in loading/tipping or to stop movement of trailer against the loading as FLTs are driven in/out.
A little trick when getting into a tight spot: Raising suspension to max on the trailer will put more weight on the leading axle, so it will tend to pivot on the front rather than middle axle, and act like a shorter wheelbase (albeit with more tail swing). Useful if you need it, but only if necessary.
To adjust the trailer suspension.
Push the Handel in and turn right or left to lower or rais the suspension, this deflates or inflates the air bag suspension.
So on arrival at the bay you don’t want to be as tight as a ducks arse against the bay as you won’t be able to rase or lower you want to be just off the bay,
When your ready To leave pull off the bay slightly pull the handle fully out to the lock position ( you shouldn’t be able to turn it ) this will then set the suspension to ride height, remember that any use of air can mean you need to build up air before moving off and in some cases cause the trailer break to apply.
Check load and secure. Close doors and go.
Glad I asked as this is one of the numerous things that can’t be covered in the driving lessons (really needs to be 2 weeks long). Will go looking for this leaver when I get near a trailer, either driving or just close enough in a yard, and hopefully imprint it into my brain as part of the walkround checks.
Note taken on “vans” too, esp as it’s mostly 7.5 tonners I’ve been driving since passing test…“I am an artic driver, honest”.
Thanks for the advice and will likely be a load more questions (although I have been reading this stuff since before Class C).
Word of warning when lifting the back end of a trailer up. A rigid will allow the wheels to move to accommodate the lift but since the unit and trailer are seperate on a artic this will not happen. When you release the park brake on the tractor you may find it lurches. This is because the trailer has pushed against the tractor unit. Same goes for dropping the air. Also, you’ll want to leave the engine running on the tractor unit because it requires more air to lift a loaded trailer. I normally leave it on fast idle.
The handle should be blue. The handle should not be able to move when in road position. Push the handle towards the body of the trailer till it goes “clunk”. Turn the handle to the right to lift, turn it to the left to drop. Pull the handle back towards you to return to road level.
Radar19:
The handle should be blue. The handle should not be able to move when in road position. Push the handle towards the body of the trailer till it goes “clunk”. Turn the handle to the right to lift, turn it to the left to drop. Pull the handle back towards you to return to road level.
Don’t think there’s any significance to the colour of the handle. All the trailers I’ve used (and that’s not a huge number by any stretch - almost all of them from only two different manufacturers) have had plain black handles.
Radar19:
The handle should be blue. The handle should not be able to move when in road position. Push the handle towards the body of the trailer till it goes “clunk”. Turn the handle to the right to lift, turn it to the left to drop. Pull the handle back towards you to return to road level.
Don’t think there’s any significance to the colour of the handle. All the trailers I’ve used (and that’s not a huge number by any stretch - almost all of them from only two different manufacturers) have had plain black handles.
We use ferry trailers from Krone and they are blue.
Radar19:
The handle should be blue. The handle should not be able to move when in road position. Push the handle towards the body of the trailer till it goes “clunk”. Turn the handle to the right to lift, turn it to the left to drop. Pull the handle back towards you to return to road level.
Don’t think there’s any significance to the colour of the handle. All the trailers I’ve used (and that’s not a huge number by any stretch - almost all of them from only two different manufacturers) have had plain black handles.
We use ferry trailers from Krone and they are blue.
The air suspension levers on trailers can be any colour, I’ve seen them red, black, blue, and I think I’ve seen green ones to, and of course if there’s no plastic coating on the lever and the paint has worn off, when they’re left standing for some time you get a rustic brown colour
Franglais:
Remember to check switch/lever is set to road position after tipping/loading. Most new ones will do so automatically after you reach 20-ish kph, but not all. If you run with air dumped or over pressured the axles weights will be all to ■■■■, the trailer will handle like a sack of crap, and braking will be severely compromised. You may be asked to alter trailer height to line up with a bay, or angle the trailer to assist in loading/tipping or to stop movement of trailer against the loading as FLTs are driven in/out.
A little trick when getting into a tight spot: Raising suspension to max on the trailer will put more weight on the leading axle, so it will tend to pivot on the front rather than middle axle, and act like a shorter wheelbase (albeit with more tail swing). Useful if you need it, but only if necessary.
Bugger me every day’s a schoolday.
I never knew that lifting the trailer suspension would alter the pivot point.
Chapeau.
Franglais:
Remember to check switch/lever is set to road position after tipping/loading. Most new ones will do so automatically after you reach 20-ish kph, but not all. If you run with air dumped or over pressured the axles weights will be all to ■■■■, the trailer will handle like a sack of crap, and braking will be severely compromised. You may be asked to alter trailer height to line up with a bay, or angle the trailer to assist in loading/tipping or to stop movement of trailer against the loading as FLTs are driven in/out.
A little trick when getting into a tight spot: Raising suspension to max on the trailer will put more weight on the leading axle, so it will tend to pivot on the front rather than middle axle, and act like a shorter wheelbase (albeit with more tail swing). Useful if you need it, but only if necessary.
Bugger me every day’s a schoolday.
I never knew that lifting the trailer suspension would alter the pivot point.
Chapeau.
And Robroy was asking if this place was useful!
So have you got adjustment on your tankers Juddian?
We don’t have any it’s all self leveling, and as I don’t know any better, I guess this could be because/part of the ant-tilt system we have.
trevHCS:
a licence to drive “vans” with bends in them
Please don’t fall into the trap of such childish nomenclature, it is unbecoming and just because one poster seems to find it funny, most don’t.
Fair enough, but each to their own and I know you won’t find a post where I’m genuinely derogatory to a class 2 driver…
I’ve been there and freely admit they have their skill requirements, so can only assume we view humour differently!
For example, my use of the term limper may also up upset you, even though I am one?
Banter isn’t for everyone, and I wouldn’t dream of enforcing it…
Evil8Beezle:
And Robroy was asking if this place was useful!
So have you got adjustment on your tankers Juddian?
We don’t have any it’s all self leveling, and as I don’t know any better, I guess this could be because/part of the ant-tilt system we have.
Anti tilt won’t have anything to do with changing trailer suspension we had DD trailers with adjustable suspension most trailers have it in less it’s on totally springs
Franglais:
Remember to check switch/lever is set to road position after tipping/loading. Most new ones will do so automatically after you reach 20-ish kph, but not all. If you run with air dumped or over pressured the axles weights will be all to ■■■■, the trailer will handle like a sack of crap, and braking will be severely compromised. You may be asked to alter trailer height to line up with a bay, or angle the trailer to assist in loading/tipping or to stop movement of trailer against the loading as FLTs are driven in/out.
A little trick when getting into a tight spot: Raising suspension to max on the trailer will put more weight on the leading axle, so it will tend to pivot on the front rather than middle axle, and act like a shorter wheelbase (albeit with more tail swing). Useful if you need it, but only if necessary.
Bugger me every day’s a schoolday.
I never knew that lifting the trailer suspension would alter the pivot point.
Chapeau.
And Robroy was asking if this place was useful!
So have you got adjustment on your tankers Juddian?
We don’t have any it’s all self leveling, and as I don’t know any better, I guess this could be because/part of the ant-tilt system we have.
Yes all of them have height levellers, none of the posh ant tilt stuff mind
Keep On Trucking:
Usually there is a separate lever. Most of the time it at the the n/s rear of the tralier. (Well all of the trailers I have come across it’s where I have said it is.)
