How does shunt button work on trailers? Never used it… Do you still need to plug any lines in with it??
The shunt button works with no lines connected, as soon as you connect the red air line, it automatically knocks off the shunt button
Also, it will only work if the trailer has got air in the tanks
All the shunt buttons have been disabled on our trailers as "we shouldn’t be shunting with no air or electric lines on " 
this is done by fitting a spring under the shunt button, also the the parking brake is applied automatically when the red line is removed.
I always considered them dangerous, it’s too easy for anyone to hook up and move the trailer without bothering with lines, it also means however that the trailer brakes are not operative.
Should be fitted with a device that chops the finger nails off any driver who presses the thing.
Small anecdote, bloke ‘‘helped’’ me change trailers one night, a billy whizz character who hasn’t got a second to live…to be honest i don’t want anyone to help with trailer changing as you get out of sequence and it all goes pear shaped, but i could hardly tell him to bugger off.
Anyway, i’m just leaving the premises and started going down the estate road and the dash is lit up like a Christmas tree with brake warnings, sure enough no trailer brake effort.
So i pull up on the side of the road and have a poke nose to see whats wrong, yep he’d pushed the shunt button and it had stuck in, it seems he uses the shunt button to save all the hours it takes to connect the red line to pull a trailer out of the bay and put the other in.
Driver snapped his red line in the yard the other day. Unfortunately the tractor was at almost right angles to the trailer and the trailer was in such a position that it would have been a complete nark to get back under it with a tug or another unit. So, with a shunter holding the line kinked shut on itself to build up pressure, push the shunt button (and then the park brake as well) to complete the turn a bit more.
So it does have it’s uses, but as with most things, it’s the misuse of it that causes accidents…
I’ve used shunt button many a time… trying to get into some tight spaces without getting the airlines caught up on those stupid round tensioners on the front of our trailers… Lines off, move on the shunt… Sorted…
same here when shunting trailer’s from the yard to the workshop, couple up, red line on, leg’s up, red off and shunt in.
philgor:
same here when shunting trailer’s from the yard to the workshop, couple up, red line on, leg’s up, red off and shunt in.
You don’t need the line on with the shunt button. Or do you mean park brake in? 
use the shunt at a couple of places i go one is a real pig blind side reverse you would almost certanly snap a line so i disconnect use the shunt then re connect better than snapping the lines and waiting for a repair
OVLOV JAY:
philgor:
same here when shunting trailer’s from the yard to the workshop, couple up, red line on, leg’s up, red off and shunt in.You don’t need the line on with the shunt button. Or do you mean park brake in?
sorry, just habit I have gotten in to after see a few trailer’s run out of air, due to the suspension valve working over time on the rough ground, even more so after it’s been sat a few day’s…
Juddian:
Should be fitted with a device that chops the finger nails off any driver who presses the thing.
Obviously you’ve never done ferry trailer port work where its often necessary to move a 3rd party trailer just a few metres in order to get your own out. No need to even wind the legs up if the ground is level.
Kate:
I’ve used shunt button many a time… trying to get into some tight spaces without getting the airlines caught up on those stupid round tensioners on the front of our trailers… Lines off, move on the shunt… Sorted…
Yeah, I’ve used it a few times where I’m in a really tight yard and it’s going to be a ‘jackknife’ round jobby, so I’ll drop the lines off, hit the shunt, jack it 'round and then hook them back up.
philgor:
OVLOV JAY:
philgor:
same here when shunting trailer’s from the yard to the workshop, couple up, red line on, leg’s up, red off and shunt in.You don’t need the line on with the shunt button. Or do you mean park brake in?
sorry, just habit I have gotten in to after see a few trailer’s run out of air, due to the suspension valve working over time on the rough ground, even more so after it’s been sat a few day’s…
You’re not using the shunt with the red airline on, it just pops back out
waynedl:
philgor:
OVLOV JAY:
philgor:
same here when shunting trailer’s from the yard to the workshop, couple up, red line on, leg’s up, red off and shunt in.You don’t need the line on with the shunt button. Or do you mean park brake in?
sorry, just habit I have gotten in to after see a few trailer’s run out of air, due to the suspension valve working over time on the rough ground, even more so after it’s been sat a few day’s…
You’re not using the shunt with the red airline on, it just pops back out
what I do Is this, if the trailer has been sat a few day’s in the yard, I couple up to it, put the red line on to put air in to the tank’s, wind the leg’s up, pull the red line off and then push the shunt in, by this point there’s enough air in the tanks to stop it running out of air, as said the yard is full of pot hole’s so can run out of air quick, even more so when you can’t find the suspension levelling valve…
If you put the line on, why then take it off and then use the shunt button 
OVLOV JAY:
If you put the line on, why then take it off and then use the shunt button
Exactly what I was going to say. Having already put it on, why on earth take it off before moving? Makes no sense at all.
philgor:
OVLOV JAY:
philgor:
same here when shunting trailer’s from the yard to the workshop, couple up, red line on, leg’s up, red off and shunt in.You don’t need the line on with the shunt button. Or do you mean park brake in?
sorry, just habit I have gotten in to after see a few trailer’s run out of air, due to the suspension valve working over time on the rough ground, even more so after it’s been sat a few day’s…
But the shunt button pops out when you connect the red line so pressing it is pointless if you’re gonna connect the line anyway.
right, let’s make this clear,
- I don’t like running with any line’s as they get tangled up and broken (they break on me I have to pay…)
- the line goes on to put air in to the tank’s to stop the brake’s locking on.
- the leg’s get wound up
- by that point there is enough air in the tank’s to ensure that the brake’s wont lock on.
- the red air line is then disconnected
- the park is taken off, and shunt is pushed in
truck and trailer coupled, no line’s to tangle or break, very little chance of the trailer running out of air and the brake’s locking on.
From the fuss some of the posts are making I’m in no doubt as to why we are paid and treated like complete imbeciles.
Surely the fact that it is called a “shunt” button explains it all? Whether you like it or not does not change it or why it is there.
Truckbling:
From the fuss some of the posts are making I’m in no doubt as to why we are paid and treated like complete imbeciles.Surely the fact that it is called a “shunt” button explains it all? Whether you like it or not does not change it or why it is there.
Except in my previous job on the wood (some know the company) where the shunt button was actually the button for the little bar that pops up behind the rear doors