- Location
- Bedfordshire
Not in all cases, yes when you disconnect the lines the brakes lock on, but when all the air is drained from the tank the brakes release.
Two "diggers" crash in Scotland
- Thread starter Sonoftheheir
- Start date
- Location
- Lincolnshire
Some confusion here about how air brakes work.
On my agri trailers (not lorries) the air puts brakes on just like the hydraulic ones do, the system has both on the same actuator.
When you hitch a trailer if there is no air in it you can move it, but connect the airlines and its solid until pressure builds up, once pressure is up you drive off.
If while driving you pull the handbrake 1 click (warning light on) they lock on hard, if you switch ignition off they lock on hard, if a line splits they lock on hard... and will stay locked on for along time until the last of the air bleeds away.
On my agri trailers (not lorries) the air puts brakes on just like the hydraulic ones do, the system has both on the same actuator.
When you hitch a trailer if there is no air in it you can move it, but connect the airlines and its solid until pressure builds up, once pressure is up you drive off.
If while driving you pull the handbrake 1 click (warning light on) they lock on hard, if you switch ignition off they lock on hard, if a line splits they lock on hard... and will stay locked on for along time until the last of the air bleeds away.
not on modern machines
- Location
- Bedfordshire
Ok, when you get a minute get trailer on air, lay underneath and dump the air in the tank, watch the brake acctuators when all the pressure is released.Any trailers only on air, I've had dealings with you have to wind the brakes off if you want to move it with no air.
Exactly my point, no air pressure, no brakes. Spent a good few years as a fitter and the easiest way to shift an air braked trailer into the workshop was to dump the air, brakes come off and your good to go.
Zetor
Member
- Location
- Northumberland
If you ripped the air lines off, the trailers own air tank will hold the brakes on, the air from this tank will not bleed out of the broken lines.
nick channer
Member
- Location
- buckinghamshire (south)
We have several trailers with worn couplings and tractors with worn hitches.
Have no plans in changing the lot
Never had one come off in the history of our framing career is what in sayin
oil barron
Member
- Location
- Aberdeenshire
But you have had one come off which resulted in a roll over on a public highway? Surely that's one too many?
Speedstar
Member
- Location
- Scottish Borders
I hope you never have a problem , as with that statement you have just said it was all your fault , Get them fixed you could kill some one with them
Paul think he needs a word in somewhere and some ones ear. I put gas through a ring hitch yesterday so no one could use it only a small cart but eye worn New eye on tommorow Game keeper was not happy he could not use it
traadilooar
Member
- Location
- Isle of Man
Does anyone know the facts?
Could be something as simple as car driver bit eager to pass bus and trailer driver faced with a head on!
Awful thing really.
Could be something as simple as car driver bit eager to pass bus and trailer driver faced with a head on!
Awful thing really.
no but according to witnesses in the news it had lost control going down the hill towards the parked bus hit a lamp post then the cars landing on one in the ditch trailer on another by the bus how true that is i have no idea but it does look like a likely scenario looking at the pictures
as for the facts they rarely ever get fully reported in the press
traadilooar
Member
- Location
- Isle of Man
I mean he may have got crossed up when faced with a blocked road, car over taking bus & tried to take avoiding action.
MGS6930
Member
- Location
- West of Scotland
This only happened a few miles from us and I can vouch that the hill he was coming down is basically a ski slope at the best of times , from the brow of the hill to where he ended up is about 800 odd metres downhill so if there was any issues with brakes that hill with that load would soon find them. The worst bit is if he'd made it another 150metres or so the road opens up with large areas of grass on both sides , but if the brakes were completely away I wouldn't even want to imagine what speed that machine reached coming down there !. A few boys up here shift machines the exact same way and their within the law, so it can be done legally. Its bad to say but I reckon it was a miracle only one person was killed when you look at the aftermath and as an old boy said to us the other night " I don't know what would be worse, seeing that loader come towards you or go by ye in the cab". I hope the investigation shows that it was an unforeseen mechanical issue and not a fault on the drivers part to give the boy some chance of living with this.
stevie boy
Member
my experience, if the trailer is modern and only on air it will have springs in the chambers to hold the brakes on if / when the air escapes, a modern artic trailer won't go anywhere with no air, you need enough air in it to push the springs off when you press the shunt button.
if it's on air / oil like every agri trailer i've used then there won't be any springs to hold the brakes on once the air escapes, because if they did you'd only be able to use it on the oil whilst there was enough air in the system to hold them off. they'll have a mechanical handbrake to hold the brakes on, a modern artic trailer won't. never leave a air / oil setup trailer parked on anything other than flat for anything other than a short period without putting the handbrake on, as it will rollaway once the air escapes
Didn't witnesses say the car was full of occupants? Only one killed what about the rest?
My brother and I were waying this up today and both of us have done thousands of hrs on fastracs moving diggers and dump trailers and we both couldn't work out how it would get away you,one thing about fastracs they have the best brakes going.
Speedstar
Member
- Location
- Scottish Borders
Unless a disc breaks they you are in trouble, we had this & they will not stopDidn't witnesses say the car was full of occupants? Only one killed what about the rest?
My brother and I were waying this up today and both of us have done thousands of hrs on fastracs moving diggers and dump trailers and we both couldn't work out how it would get away you,one thing about fastracs they have the best brakes going.
Not sure if that Fastrac will have had a set of Disc's as it used to pull a 3 axle tipping trailer all the time & was all ways the top size of 44 ton loaded, this was before this lad bought it
Air would still work though wouldn't it?
I suppose it would then depend on how good the trailer brakes were.
Speedstar
Member
- Location
- Scottish Borders
No the brakes are air over fluid, if you loss the fluid you have no brakes
Hilly
Member
- Location
- Scottish Borders.
Air or not it could have had brake failure, it would be drums and if the shoes are not good could have gone past the cams.
Yes but trailers on air,well should be.
One thing from the crash pictures,he had the digger chained on well and a strap over the buckets.