Attaching trailer air brakes

killie_cowboy

Member
Livestock Farmer
Location
Scottish Borders
why the difference between Ag and trucks?
(i guess cost or something)

what i dont understand is why they didnt introduce twin line hydraulics the same, rather than using the accuulator (so now, if accumulator fails, you dont have a "fail safe" system, whihc actually means IMO, they system is not fail safe at all?)
Will be because truck airbrakes don't come air/oil, suppose nothings fail safe if you look at it that way
 

Renaultman

Member
Arable Farmer
Location
Darlington
So there couldn’t have been any air in it when I picked it up as when I failed to plug the air in I simply hooked up the oil instead and trundled off.
I’ll have to go have a look for a drain valve now.
Mine has a dump/shunt valve. Releases the brakes and they won't come back on until you reconnect air lines.
 

Renaultman

Member
Arable Farmer
Location
Darlington
No experience of air brakes on tractors but on a Mercedes lorry it's always easier to connect the yellow line first. Doesn't seem to make any difference what you connect first on a Volvo. Don't remember any issues with Scania or DAF either, but it's been a while.
DAF Merc etc put air through the yellow line to use trailer brakes when Handbrake is applied, Volvo and Scania don't. If you get stuck on an icy bank and try to apply your handbrake it can become somewhat interesting.
 
DAF Merc etc put air through the yellow line to use trailer brakes when Handbrake is applied, Volvo and Scania don't. If you get stuck on an icy bank and try to apply your handbrake it can become somewhat interesting.
Since 2018, all EU-approved ag. tractors with air (trailer) brakes must pressurise the Yellow ('Control') line when the tractor parking brake is applied ...... This then applies the trailer's Service brakes. All ag. trailers are still required to have a mechanically-applied Parking brake though .... but that could be a wire rope & ratchet or a spring brake actuator ... will do the same thing.

As for Emergency/Failsafe systems, all rely on there being some kind of 'stored energy' source on the trailer. That might be air pressure in a trailer-mounted reservoir, hydraulic pressure in an accumulator or mechanical energy in a spring. However, the rules surrounding use of Spring Brakes for this purpose are a bit more restrictive. You can only trigger a spring once: the other (hydraulic or pneumatic) systems must have enough spare capacity to be used a number of times without being re-filled.

Are Volvo & Scania running an EBS system (electronic braking control)? I'd have thought all trucks would have had to apply the trailer brakes when the tractor unit park brake is applied ....... But then I don't know much about trucks :confused:
 

Mur Huwcun

Member
Livestock Farmer
Location
North West Wales
Since 2018, all EU-approved ag. tractors with air (trailer) brakes must pressurise the Yellow ('Control') line when the tractor parking brake is applied ...... This then applies the trailer's Service brakes. All ag. trailers are still required to have a mechanically-applied Parking brake though .... but that could be a wire rope & ratchet or a spring brake actuator ... will do the same thing.

As for Emergency/Failsafe systems, all rely on there being some kind of 'stored energy' source on the trailer. That might be air pressure in a trailer-mounted reservoir, hydraulic pressure in an accumulator or mechanical energy in a spring. However, the rules surrounding use of Spring Brakes for this purpose are a bit more restrictive. You can only trigger a spring once: the other (hydraulic or pneumatic) systems must have enough spare capacity to be used a number of times without being re-filled.

Are Volvo & Scania running an EBS system (electronic braking control)? I'd have thought all trucks would have had to apply the trailer brakes when the tractor unit park brake is applied ....... But then I don't know much about trucks :confused:

Ag system is silly really as if theiretically in the event a trailer came off brakes would come on, now on the road in traffic who would still be calm and collective enough to jump out and apply handbrake just in case the air leaked out!! Same as you can park a trailer with air in it only to return and find it eeeerrrrm, slightly more down the yard!!!

All tractor units not applying handbrake on trailer is another silly one, have you seen videos of trucks running away when plant are loaded onto low loaders and weight is inadvertently taken off drive axle as the machine goes up the ramp.
 

Andrew

Member
Location
Huntingdon, UK
Since 2018, all EU-approved ag. tractors with air (trailer) brakes must pressurise the Yellow ('Control') line when the tractor parking brake is applied ...... This then applies the trailer's Service brakes. All ag. trailers are still required to have a mechanically-applied Parking brake though .... but that could be a wire rope & ratchet or a spring brake actuator ... will do the same thing.

As for Emergency/Failsafe systems, all rely on there being some kind of 'stored energy' source on the trailer. That might be air pressure in a trailer-mounted reservoir, hydraulic pressure in an accumulator or mechanical energy in a spring. However, the rules surrounding use of Spring Brakes for this purpose are a bit more restrictive. You can only trigger a spring once: the other (hydraulic or pneumatic) systems must have enough spare capacity to be used a number of times without being re-filled.

Are Volvo & Scania running an EBS system (electronic braking control)? I'd have thought all trucks would have had to apply the trailer brakes when the tractor unit park brake is applied ....... But then I don't know much about trucks :confused:

Yes they have EBS, but Renaultman is right. Our Scania midlift, when you apply the handbrake in the cab, only brakes the 1st and 3rd axle. Not the trailer at all.
On the C&E driving test, they also don't give a fig which airline you disconnect or connect first, (in fact they now advise red first as the air builds up quicker) but you have to put the trailer handbrake on before you do anything and off just before you drive off.
 

Renaultman

Member
Arable Farmer
Location
Darlington
Since 2018, all EU-approved ag. tractors with air (trailer) brakes must pressurise the Yellow ('Control') line when the tractor parking brake is applied ...... This then applies the trailer's Service brakes. All ag. trailers are still required to have a mechanically-applied Parking brake though .... but that could be a wire rope & ratchet or a spring brake actuator ... will do the same thing.

As for Emergency/Failsafe systems, all rely on there being some kind of 'stored energy' source on the trailer. That might be air pressure in a trailer-mounted reservoir, hydraulic pressure in an accumulator or mechanical energy in a spring. However, the rules surrounding use of Spring Brakes for this purpose are a bit more restrictive. You can only trigger a spring once: the other (hydraulic or pneumatic) systems must have enough spare capacity to be used a number of times without being re-filled.

Are Volvo & Scania running an EBS system (electronic braking control)? I'd have thought all trucks would have had to apply the trailer brakes when the tractor unit park brake is applied ....... But then I don't know much about trucks :confused:
Nearly everything is EBS now and spring actuators have been mandatory for a long time. This may be what gets them off not having to pressurise the yellow line when the park brake is applied. I've got a fairly new Richard Western high speed tipper. I really rate it, but tech wise it is 30 years behind a modern artic trailer (Which makes it easier for me to maintain)
 

Tony1989

Member
Yes they have EBS, but Renaultman is right. Our Scania midlift, when you apply the handbrake in the cab, only brakes the 1st and 3rd axle. Not the trailer at all.
On the C&E driving test, they also don't give a fig which airline you disconnect or connect first, (in fact they now advise red first as the air builds up quicker) but you have to put the trailer handbrake on before you do anything and off just before you drive off.
You can change the handbrake lever in a scania so that it will put trailer brakes on
 

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Man fined £300 for bonfire-related waste offences

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Written by William Kellett from Agriland

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A man has pleaded guilty at Newtownards Magistrates’ Court to waste offences relating to a bonfire next to the electrical sub-station on the Circular Road in Newtownards, Co. Down.

Gareth Gill (51) of Abbot’s Walk, Newtownards pleaded guilty to two charges under the Waste and Contaminated Land (Northern Ireland) Order 1997, for which he was fined £150 each and ordered to pay a £15 offender’s levy

On June 25, 2018, PSNI officers went to Gill’s yard, where they found a large amount of waste consisting of scrap wood, pallets, carpet and underlay.

Discussion with Northern Ireland Environment Agency (NIEA) officers confirmed the site...
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