I can’t post a poll here, which is odd because the forum supports it, [bugger, I’ve just spotted how to do it] but anyway -
Trailer parking brakes.
As you probably all know, you have to pull the knob to put the park brake on.
EVERYWHERE ELSE IN INDUSTRY you push the Big Red Knob to STOP something from happening.
Isn’t it about time we adopted the same rules as everybody else ? After all, it is easier to hit the button than pull it out when the trailer starts to move, especially if you’re in a rush. That’s why the industry standard was designed that way.
A lot of people who go into truck driving come from other areas of industry, and are used to the sensible way of doing it.
All they have to do is swap the pipes on the switch, so it won’t cost anything, but it will be so much easier to understand.
OK there will be a period when the older guys will have to think about what they’re doing, but surely they are the best ones to be doing the thinking, and we can have stickers next to the button for a while.
What do you all think ?
If I get a favourable reaction here, I’ll ask a few other people then try to push it through at a higher level.
in american truck they have the pull push buttons on the dash for the brakes. maybe its set that way so mr usa doesnt accidently hit the trl brake whilst doing 80+ mph. better to have a pull on push off in that scenario
Steve-o:
in american truck they have the pull push buttons on the dash for the brakes. maybe its set that way so mr usa doesnt accidently hit the trl brake whilst doing 80+ mph. better to have a pull on push off in that scenario
Steve-o:
in american truck they have the pull push buttons on the dash for the brakes. maybe its set that way so mr usa doesnt accidently hit the trl brake whilst doing 80+ mph. better to have a pull on push off in that scenario
Steve
So what happens when they drop the trailer ?
It would be silly having the in cab buttons push off pull on and on trl controls the other way round don’t you think?
Steve-o:
in american truck they have the pull push buttons on the dash for the brakes. maybe its set that way so mr usa doesnt accidently hit the trl brake whilst doing 80+ mph. better to have a pull on push off in that scenario
Steve
So what happens when they drop the trailer ?
There are 2 push/pull buttons on American trucks, one controls the unit parking brakes (red) & the other (yellow) controls the air supply to the trailer, you push it into release the parking brake/supply air to the trailer. When dropping the trailer, just pull out the yellow knob & it stops supplying air to the trailer, this engages a valve that dumps all the air from the trailer braking system & the spring brakes come on. There is no secondary parking brake on trailers over here.
I don’t understand the point of a trailer brake on a Euro trailer really, when you drop a trailer you disconnect the airlines & removing the red line (or emergency if you have black ones) applies the spring brakes, the ‘trailer brake knob’ only does the same thing, it shuts off the air supply that keeps the spring brakes from coming on, so when you drop a trailer it is automatically braked, it must be because of the way the air is supplied from the unit, in an American truck the driver has to manually push in the trailer supply valve so he will be in the cab at that point, in a Euro truck it is done automatically, as you connect the airline the trailer brakes release, not good if you don’t have the unit parking brake applied in either case but in the American truck it’s a lot easier to hit the brakes from the cab than it is from the catwalk of a Euro truck, unless you have really long arms!
IIRC the seperate trailer brake started to appear more frequently on UK trailers in the late 80s, at about the same time as self sealing suzies, before that a tap at the base of the airlines was used to open the air supply to the trailer. Before the introduction of spring brakes, trailers had a manual parking brake, a lever controlled a ratchet & wirethat was connected to the slack adjusters that manually applied the brakes.
Don’t worry if you get confused about pushing it/in pulling it out, I know if you do it wrong when dropping the trailer the brakes are applied as soon as you disconnect the red airline, if you’re picking up the trailer & do it wrong, you ain’t going far anyway
Steve-o:
…I don’t understand the point of a trailer brake on a Euro trailer really, when you drop a trailer you disconnect the airlines & removing the red line (or emergency if you have black ones) applies the spring brakes, the ‘trailer brake knob’ only does the same thing, it shuts off the air supply that keeps the spring brakes from coming on, so when you drop a trailer it is automatically braked…
the point of the trailer brake is for when the idiots forget to put the handbrake on on the tractor unit, if he connects the red air supply to the trailer, the trailer can roll away with the driver standing on the catwalk if the truck handbrake is not on, if there is a trailer brake in use, it cannot roll away.
it is there for a safety feature, drivers have been killed trying to jump off moving vehicles due to forgetting to apply the hand brake
i admit to doing that once … backed under a trailer…plugged in the air lines and away it went with me on the catwalk…luckily it only went back about 10 feet till it hit the trailer behind me…lesson learned.
oh and harking back to a previous thread about aplying trailer park brakes…this was when i worked for stobart…on the induction we were told NOT to apply trailer park breaks in depots…no excuse for not putting the park brake on the unit i know…but it would make this scenario impossible?
while i agree with the OP’s point about stop buttons being pushed in most circumstances it would be an incredibly dangerous move to make to change it round now, there would be an inevitable crossover period when there would be some trailers that required the button to be pulled and some pushed.
reminds me of the changeover to self sealing suzies from the old type with a tap, i did a chan geover once and the lad had coupled up for me, he was used to the new type of suzies, i should have checked as this unit had the old type, i drove off and as i approached the gate to exit the yard applied the brakes top find only the unit brakes were working, a definate brown trouser moment heading for a busy road!
I took my test with a trailer that had a ratchet brake, and they were a bit dodgy too. I still think it would be more consistent with the idea of STOP if the button had to be pushed in. The only thing I can think of that might go against it is if a rock hit it while you’re driving along. But that’s about as likely as the unit and trailer parting company and the brakes come on then anyway.
I don’t think it would be that dangerous during the changeover. Most people drop their own trailers and it would be obvious to them which way it went. On coupling up, you check the brake beforehand and the newer ones would look different, the standard big red mushroom button, that you have to twist to release. I know of other areas where things work differently even though they look the same. There are maybe 4 or 5 different coupling releases on wagon and drag, and I’ve even used a hiab that was identical to others in every way, except the controls were back to front. This led to me opening the grab when I wanted to extend the boom. Luckily the load of tiles was only 3 feet off the ground at the time. Smashed the tiles completely, but no-one was underneath.
Got your buttons the wrong way round there, Mark. The yellow is the unit, red the trailer. I suspect you have chrome buttons in your truck though.
The reason buttons are pull/ apply is because some are automatic and pop out when the air is disconnected or drops below tolerance. Tesco adopted this system in the 90’s, and it has been standard here for decades. If the air drops below 55psi then the brakes will apply themselves and both buttons will pop out.
Something else, all trailer brakes will lock on if the red/emergency line is disconnected, but on some, indeed many trailers, that does not necessarily mean the trailer brake is applied. Unless there are spring brakes fitted then the brakes will only last as long as the air supply. Once the air is depleted, the brakes will release.
As the buttons have been this way for a long time, why would you want to see it changed? You pull a handbrake on, don’t you?
It always amazes me how many people don’t use the parking brake when dropping the trailer rightly or
wrongly I think that having TWO sets of brakes applied is safer than one when coupling a trailer I am
sure we have all left the unit brake OFF at sometime or other
bobthedog:
As the buttons have been this way for a long time, why would you want to see it changed? You pull a handbrake on, don’t you?
As I said, every other piece of machinery in industry has an emergency stop button that you push. The trailer brake button looks like an emergency stop button but works in the opposite direction. Why make it different ?
They (emergency stop buttons) are designed that way because you don’t have to think about how to turn it on, but you do have to think to turn it off. Surely this applies to trailer brakes too ?
I don’t know if it is the reason, but there is much less chance that a passing piece of flying debris would pull the button out than of it knocking it in. Sudden application of the trailer brakes could be nasty! Also small pedestrians (kids) are probably more likely to push it than pull when passing you in a queue (or running underneath at the lights - yes it’s happened to me!).
Why would you compare a truck to a lathe? It makes no sense. It is easier to spring load a button to pop out rather than in, so they pop out. If you were around when the brakes were the ratchet type then you wouldn’t ever have thought about it. They all state “pull to apply” on them, so it is obvious enough. The shunt valve is push in because it is a temporary release. Once the red line is pulled the button pops out and the brakes are reapplied.
If you put the red line on having forgotten to put the handbrake on then push or pull doesn’t matter, especially if the button is halfway back the chassis.
You need a Law to know what and how to do.
For the MOT is a Law too.
In History,as a Handbrake is needed by Law,was a Manual Handle.
Later said anyone,why that compleceted.How if we just use such a Valve as US Trucks have fitted.
Well,and here it is.
That you pull the Button has to do that the Valve is build that Way since 100 Years,and,…
if you do it wrong when dropping the trailer the brakes are applied as soon as you disconnect the red airline, if you’re picking up the trailer & do it wrong, you ain’t going far anyway 
