I got spooked by something this morning. About a mile from the yard after a returning from a long night my lorry suddenly shuddered to a complete halt in the middle of the road. My red lead had popped off. This has never happened to me in my 17 years class 1 career.
I had no idea why it popped off, but to get myself going and unblock the road I popped it back on and got back to the yard. When I got back I looked closer and realised no matter where the collar was turned, the red lead could be pulled off simply by yanking it off. The collar didn’t need lining up witht he little ball-bearing as normal, and simply rode over it. I’ve never come across this before, and it didn’t look or feel worn. Nothing about its appearance roused my suspicions.
I know the vast majority of well experienced drivers on here obviously check for this potential defect, but for those less experienced drivers like myself, beware of this. It’s something I’d never considered. It was a random shuddering halt, and I hate the thought of what might have happened if that occurred flying down the M1 with the usual suspects 6ft from my back door.
Maybe on the trailer nozzle it is worn.
I dunno, hard to know without seeing both.
Easy solution is just to give your air lines a yank just to make sure they are secure though.
Never seen it happen on the road but can remember it happening a few times when we had taps.You think its connected then it sometimes blew off when the tap was opened.
Salt and road dirt mixed with damp can jam the bearings and the locking collar and stop it connecting properly especially in the case of drawbars.
Keep some WD20 in the locker and wash the couplings with it.Also a drop of oil after and the WD 40 will thin it out.But always give all the lines a good pull after you’ve connected them to help make sure they’ve locked.
In general I had far less aggro with palm couplings it’s anyone’s gues why we have to be different to everyone else in that regard.
Had it happen after some 40 miles on an empty dry motorway at 60mph+ back in the day, left two rows of black lines and a road full of tyre smoke from the middle lane over several hundred yards onto the hard shoulder, lines took about a month to wear out 
8 threepenny bit tyres too.
Fittings looked fairly new, too new maybe.
In house mechanics put it down to poor quality factor parts.
Juddian:
Had it happen after some 40 miles on an empty dry motorway at 60mph+ back in the day, left two rows of black lines and a road full of tyre smoke from the middle lane over several hundred yards onto the hard shoulder, lines took about a month to wear out
8 threepenny bit tyres too.
Fittings looked fairly new, too new maybe.
In house mechanics put it down to poor quality factor parts.
Yeah, I was in a 69 plate motor with 6 month old trailer. Weirdly it wouldn’t reverse properly once back at the yard. It wouldn’t move backwards.
ezydriver:
Juddian:
Had it happen after some 40 miles on an empty dry motorway at 60mph+ back in the day, left two rows of black lines and a road full of tyre smoke from the middle lane over several hundred yards onto the hard shoulder, lines took about a month to wear out
8 threepenny bit tyres too.
Fittings looked fairly new, too new maybe.
In house mechanics put it down to poor quality factor parts.
Yeah, I was in a 69 plate motor with 6 month old trailer. Weirdly it wouldn’t reverse properly once back at the yard. It wouldn’t move backwards.
I have a trailer that doesn’t reverse properly sometimes it doesn’t go where it’s supposed to must be trailer it can’t be me 
Uncleskid:
ezydriver:
Juddian:
Had it happen after some 40 miles on an empty dry motorway at 60mph+ back in the day, left two rows of black lines and a road full of tyre smoke from the middle lane over several hundred yards onto the hard shoulder, lines took about a month to wear out
8 threepenny bit tyres too.
Fittings looked fairly new, too new maybe.
In house mechanics put it down to poor quality factor parts.
Yeah, I was in a 69 plate motor with 6 month old trailer. Weirdly it wouldn’t reverse properly once back at the yard. It wouldn’t move backwards.
I have a trailer that doesn’t reverse properly sometimes it doesn’t go where it’s supposed to must be trailer it can’t be me
Tuffnells had a load of them when I did a bit of agency for them. I put no end of defects in, but it did no good.
I have driven two different Scania’s this week one 66 plate one 67 plate. Both had worn red coupling where you could pull the coupling off without lining up the pin. 
ezydriver:
Juddian:
Had it happen after some 40 miles on an empty dry motorway at 60mph+ back in the day, left two rows of black lines and a road full of tyre smoke from the middle lane over several hundred yards onto the hard shoulder, lines took about a month to wear out
8 threepenny bit tyres too.
Fittings looked fairly new, too new maybe.
In house mechanics put it down to poor quality factor parts.
Yeah, I was in a 69 plate motor with 6 month old trailer. Weirdly it wouldn’t reverse properly once back at the yard. It wouldn’t move backwards.
Does it start to reverse initially but then lock up as if someone has applied the trailer brake? If so it could be that your trailers are fitted with proximity reversing sensors and the sensor is dirty or faulty. When it happens again, disconnect your ABS lead and see if it will move then. If that doesn’t work, try disconnecting your secondary electrics as well. If it drives forward okay then I’m 99% sure that’s what is causing it. We had this problem with some tankers on lease a while ago.
The air connections coming off on their own are because they’re not sealing on the male connector(s). If you swivel and wiggle it you’ll probably hear some air leaking out. Clean and/or sand away any signs of corrosion or contamination so that the male ends are smooth as a baby’s arse and lubricate the female ends so that the spring locking collar engages on its own and spins freely. I’ve just had this problem on my unit and one trailer in particular and it’s made a world of difference cleaning it all up. If you’re not sure if air is leaking because you can’t hear it, rub some washing up liquid around the connections and you’ll see it blowing bubbles if it is. 
Mick Bracewell:
Does it start to reverse initially but then lock up as if someone has applied the trailer brake? If so it could be that your trailers are fitted with proximity reversing sensors and the sensor is dirty or faulty. When it happens again, disconnect your ABS lead and see if it will move then. If that doesn’t work, try disconnecting your secondary electrics as well. If it drives forward okay then I’m 99% sure that’s what is causing it. We had this problem with some tankers on lease a while ago.
The air connections coming off on their own are because they’re not sealing on the male connector(s). If you swivel and wiggle it you’ll probably hear some air leaking out. Clean and/or sand away any signs of corrosion or contamination so that the male ends are smooth as a baby’s arse and lubricate the female ends so that the spring locking collar engages on its own and spins freely. I’ve just had this problem on my unit and one trailer in particular and it’s made a world of difference cleaning it all up. If you’re not sure if air is leaking because you can’t hear it, rub some washing up liquid around the connections and you’ll see it blowing bubbles if it is.
There was no air leak. On closer inspection the collar had a somewhat slack fitting, and was riding over the ball-bearing. But it wasn’t apparent until you physically yanked it, and then it just pulled off regardless of the collar’s location. I did notice the collar kept sticking, as if a good squirt of WD-40 would have worked wonders. Not sure if that had something to do with it. All in all it was something I’ve never encountered before, so it played on my mind a bit.
.
In that case I’d say it was possibly the ball bearings inside the female end were seized up with crud. When the collar is seated correctly they should prevent the coupling from detaching. When you move the collar back to disconnect it, it frees the ball bearing grip and allows the coupling to detach. Regardless of whether or not the collar slides over the notch when it shouldn’t, it shouldn’t be able to detach from the coupling at all unless someone physically slides the collar back first in order to release the ball bearings.
Mick Bracewell:
In that case I’d say it was possibly the ball bearings inside the female end were seized up with crud. When the collar is seated correctly they should prevent the coupling from detaching. When you move the collar back to disconnect it, it frees the ball bearing grip and allows the coupling to detach. Regardless of whether or not the collar slides over the notch when it shouldn’t, it shouldn’t be able to detach from the coupling at all unless someone physically slides the collar back first in order to release the ball bearings.
The bearings seize and won’t allow the collar to slide to lock them properly or sometimes the collar itself gets stuck same result.You can learn to tell by the feel of it whether its a dodgy coupling.It either feels mushy and sticky or free with a good positive snap as it grips and locks and the collar should be easy to slide.IE like a well oiled piece of machinery and that’s their problem in the dirty salty damp real world.
ezydriver:
Tuffnells had a load of them when I did a bit of agency for them. I put no end of defects in, but it did no good.
Tuffnells attitude is if it still works there is no issue.
Although I rarely got use the artics at Tuffnells.
As one of the few people who could reverse an A-frame trailer I was stuck on those which were such a pain. God… those detachable bodies were such a pain in the ■■■ as well. The legs were often stiff so carrying a hammer was a requirement.
Tuffnells was fun though. H&S was an afterthought.
I remember one time the detachable body only had 3 legs so they use a forklift for extra support.
Suedehead:
Spooky 
Very
I guess he doesn’t twist the ends so that notch doesn’t line up with ■■■■■■ bit when putting the lines on then…
As well as putting grease on the fifth wheel, the airlines need oil to keep the sliding parts free, someone started a thread asking about how to lubricate a red airline, its the yellow one too that needs attention.
You don’t need gallons of oil lathering around the C Coupling, just a little squirt from an oil can. Its a major advantage of palm couplings, low maintenance!
Wheel Nut:
As well as putting grease on the fifth wheel, the airlines need oil to keep the sliding parts free, someone started a thread asking about how to lubricate a red airline, its the yellow one too that needs attention.
You don’t need gallons of oil lathering around the C Coupling, just a little squirt from an oil can. Its a major advantage of palm couplings, low maintenance!
^ This ( and the blue one 
)
Just had this happen while shunnting a trailer, upon looking at the red line, the problem is clear, I could also pull red line off without engaging the collar, the collar is bevelled, which allows it to slip slightly over the indent ball.
biggriffin:
Just had this happen while shunnting a trailer, upon looking at the red line, the problem is clear, I could also pull red line off without engaging the collar, the collar is bevelled, which allows it to slip slightly over the indent ball.
That’s exactly what happened. The collar went over that ball no matter where the collar was positioned, so I could just yank the line off. But this time it popped itself off while I was driving.