First up - I’m new to this so apologies if it’s a stupid question.
Driving a newish MAN tractor unit and tri axle step frame trailer.
On one of my drops today, tight yard, I went in forward and spun the unit round on full lock then had to reverse and tighten it up even further to avoid a stack of goods. So very tight round, unit going forward and trailer backwards till I could straighten it up to unload. Suzies pulled really tight and round the front of the trailer but I kept an eye on them and there still seemed to be some slack (not a lot). I got out to make sure nothing was hitting anything as well!!
When I left the yard I had a low air pressure warning and a “do not shift” message - would have stopped to wait for pressure to come back up, but someone in a rigid beeping his horn and demanding to be let out so I kept moving, got out on to busy dual carriageway at which point no gears and no power. Revved the engine to see if I could get air pressure up, no joy. Got up on the back with an audience of annoyed motorists and a bus driver, disconnected air lines and reconnected making sure nothing was tangled. Got back in cab - air pressure now up but no movement - trailer wheels locked. Got out and found the trailer brake button was out, pressed it in, bowed to audience (now including two bus drivers) and was able to move…
Sweating slightly (well a lot, as blocking a major road in Birmingham…).
Was the problem likely to be a kink in an airline? Would that explain the drop in pressure and then the trailer brake button popping? And if this aint a completely daft question how far round can you get a tractor unit facing the other way to the trailer - presumably either lines are pulled out or at some stage the trailer hits the unit (I was watching out for this but everything missed - this time!).
If you do have to spin it all round really tight and you are pulling a curtainside trailer,
check as you straighten up that the suzies have not got caught up on the ratchets!
axletramp:
If you do have to spin it all round really tight and you are pulling a curtainside trailer,
check as you straighten up that the suzies have not got caught up on the ratchets!
Would guess either worn or not correctly on coupling on the red line that then let air escape after being pulled at hard by the susie - based on the recoupling curing it and park brake popping on.(Edit - ignore that didn’t realise parking didn’t come on before you recoupled, think probably just slow air build and the time you were on the catwalk was enough)
I have seen suspension hangers torn off trailer chassis from too tight screwing round of loaded triaxle trailers.
As Saamon says above…MAN must use a toy tyre inflator as the main compressor, not surprising in the least if you had a double shunt it would empty the tanks, with a full size triaxle it can take about 5 minutes at high revs to build the air back up again.
Standing joke at our place, literally standing …have to let 'em run for the whole 15 minute daily check round if the air is fully drained, about as useful as a clowns fall apart car at Billy Smarts circus.
shuttlespanker:
the best way to do it, if it is as tight as that, is to disconnect the suzzies completely from the trailer, then push the shunt valve on the trailer
this way, you can not rip any of the lines off, once you have straightened up again, reconnect the lines
theoretically, you can go all the way until the back of the air kit on the unit is touching the trailer
Sounds to me there is no shunt button if the trailer brake pop on.
kvin:
First up - I’m new to this so apologies if it’s a stupid question.
someone in a rigid beeping his horn and demanding to be let out so I kept moving,
1, Stay put or back up into the yard, tell him you have a problem with the air if he wants to stress that’s his heart attack, you’ll put yourself in a worse place by going out on the dual carriage way.
2. It’s not a stupid question
We go into a lot of places dairy crest home del sites sainsbuys supermarkets which are very tight we have a fleet of 11 plate tgx 440’s we are always losing air even on coupling up to extent we are not reaching fuel targets on tickover
As others have said, sod anyone waiting, if your truck needs air, it stays put, there may have been a serious fault and then you’d have been stranded on the dual carriageway waiting for recovery and got a damned site more hassle than 1 - supposedly professional - driver could give you.
Some trailer brakes automatically pop when you drop the red airline, but will still have a shunt button, the shunt button is nothing to do with the park brake button urban859.
If possible in future - obviously not if you’re going to end up blocking a main road or amulance route or anything - try and drop the suzi’s off and use the shunt for super tight turns, but you shouldn’t have to really as has been mentioned.
after coming out of a yard after picking up a new trailer that had no air in
i also have got down the road and had the engine cut out , trailer wheels locking
no pressure do not shift etc
what i do now to remedy the situation
is to rev up the engine and on a man press cruise control memory button
or on a daf rev up then pull the cruise control lever
then you can get out the cab with handbrake on of course
and the engine is still reving up fast or hard by itself
then i stick 2 fingers up at anyone who has bibbed thier horn at me
then i dissconect the red air line and wait 2 minutes
while the engine is reving up hard by itself
then i connect the red air line and see if it makes that loud gushing noise
that releases the trailer brakes
if it doesnt wait a bit longer and try again
then connect and dissconect red air line a couple of times when you hear gushing noise
you should be ok then
but if you do pick up a trailer that has no or very little air
i find it best to do this procedure before setting off
and never leave the yard on low air pressure
waynedl:
As others have said, sod anyone waiting, if your truck needs air, it stays put, there may have been a serious fault and then you’d have been stranded on the dual carriageway waiting for recovery and got a damned site more hassle than 1 - supposedly professional - driver could give you.
Some trailer brakes automatically pop when you drop the red airline, but will still have a shunt button, the shunt button is nothing to do with the park brake button urban859.
If possible in future - obviously not if you’re going to end up blocking a main road or amulance route or anything - try and drop the suzi’s off and use the shunt for super tight turns, but you shouldn’t have to really as has been mentioned.
In fact you are wrong some of our deckers at currys do not all have shunt buttons and being a shunter we have to use the red line
We have moved trailer park brake buttons on to the trailer headboards and disabled the shunt for a couple of retailers trailer fleets. I don’t think it’s a bad idea but we have had service call outs when drivers couldn’t find the new location.
A few trailors at dhl have a plate over the shunt button much to the annoyance to the dayshift shunters who try and drag a trailor with locked brakes round the yards
jayeastanglia:
A few trailors at dhl have a plate over the shunt button much to the annoyance to the dayshift shunters who try and drag a trailor with locked brakes round the yards
A lot now are fitted with a spring under the shunt button (more H&S crap) , so it can’t be pushed in, unless you unscrew the button remove the spring and then screw the button back on, then returns it to a normal shunt button.
shuttlespanker:
the best way to do it, if it is as tight as that, is to disconnect the suzzies completely from the trailer, then push the shunt valve on the trailer
this way, you can not rip any of the lines off, once you have straightened up again, reconnect the lines
theoretically, you can go all the way until the back of the air kit on the unit is touching the trailer
I saw a driver actually do this today.
Considering he was empty, the yard wasn’t that tight and I was spotting for him I didn’t really think it was worth it but at least he was being careful.
Perhaps, he might even check the yard is clear on foot next time…?
Spent a day today doing drops in the same tractor unit, it was slow to build pressure a couple of times so as suggested sat and ran the engine (while looking at the map for the next drop).
Thanks for the quick and useful advice and the tips. The lines do indeed run right across the ratchets on the curtainsides of the trailer I had today when knifed right round…I got out and untangled one. Off my own topic it amazes me how even new stores/merchants etc have no loading areas or access for trucks but get all their deliveries in a busy car park…it’s not just that places weren’t designed for modern trucks, the new places we have to go aren’t being designed for trucks either.
…have to let 'em run for the whole 15 minute daily check round if the air is fully drained, about as useful as a clowns fall apart car at Billy Smarts circus.
- driver could give you.