Wheel Nut:
What about if its a Schmitz or Crane Fruehauf Trailor (sic)The Eurojohnies still use wheel chocks when lifting and leaving.
Those bright yellow plastic thingies?
About as much use as a chocolate fireguard, unless wedged firmly by boot or mallet into the tyre have seen them being pushed down the road by said tyre until they meet something rough or sticking up that gives them grip, whence the tyre crushes and/or smashes them into skip fodder once the vehicle gets moving.
Ok with this thread in mind I looked at how the connection works on the red airline yesterday. At least on this type of airline (dunno if there are other brands) there are three claws/teeth that sit in a groove on the male part of the fitting on the trailor. When you pull the collar back it allows them to be pushed out the way until the female bit is home then spring back into the aforementioned groove. I can see that if one or more of these teeth were dodgy i would get the sittuation i had on sunday with the airline flying off on its own and the airline flying off the second the collar cutout was lined up with the pin on the male part.
Question is what is the point of twisting the collar round. Im sure i was told that it was a belt and braces thing incase some how the collar got caught up it couldnt be pulled back.
cooper1203:
Question is what is the point of twisting the collar round. Im sure i was told that it was a belt and braces thing incase some how the collar got caught up it couldnt be pulled back.
What you were told is pretty much spot on. A fail safe if you like. Not twisting the collar shouldn’t cause any problems, the same as not engaging the fifth wheel clip shouldn’t. But why take the chance?
Tugs tend to have the ■■■■■■ drilled out so negating the need to locate the collar before taking the airline off, but these are generally not used on the road (obviously there are exceptions) and are picking up or dropping off ten to twenty trailers an hour, so it’s just a time saving thing.
Wheel Nut:
What about if its a Schmitz or Crane Fruehauf Trailor (sic)The Eurojohnies still use wheel chocks when lifting and leaving.
Wheel chocks are useless. I drove for about 20 feet last night before I remembered the trailer had plastic chocks both sides, sliding along the ground.
cooper1203:
Ok with this thread in mind I looked at how the connection works on the red airline yesterday. At least on this type of airline (dunno if there are other brands) there are three claws/teeth that sit in a groove on the male part of the fitting on the trailor. When you pull the collar back it allows them to be pushed out the way until the female bit is home then spring back into the aforementioned groove. I can see that if one or more of these teeth were dodgy i would get the sittuation i had on sunday with the airline flying off on its own and the airline flying off the second the collar cutout was lined up with the pin on the male part.Question is what is the point of twisting the collar round. Im sure i was told that it was a belt and braces thing incase some how the collar got caught up it couldnt be pulled back.
If the spring holding the collar is weak then it will easily disconnect itself, unless you spin the collar away from the ■■■■■■, then you are not relying on the spring.
cooper1203:
Ok with this thread in mind I looked at how the connection works on the red airline yesterday. At least on this type of airline (dunno if there are other brands) there are three claws/teeth that sit in a groove on the male part of the fitting on the trailor. When you pull the collar back it allows them to be pushed out the way until the female bit is home then spring back into the aforementioned groove. I can see that if one or more of these teeth were dodgy i would get the sittuation i had on sunday with the airline flying off on its own and the airline flying off the second the collar cutout was lined up with the pin on the male part.Question is what is the point of twisting the collar round. Im sure i was told that it was a belt and braces thing incase some how the collar got caught up it couldnt be pulled back.
By twisting the collar you’re also proving that’s fully / correctly seated, as in the 3 ballbearings are completely sat in the groove. I’ve had it on an agricultural tractor with hydraulic brakes, but basically the same style of coupling but without the locating pin.
The balls must have only just slightly gone over the edge of the groove, but not dropped in, but it was enough to hold it in position and look like it’s normally connected, I jumped in and pressed the brake and the fitting flew off.
If there’d have been a locating pin you had to clear before you could twist, it would have shown something wasn’t right as the collar wouldn’t have been able to move enough to clear the pin. It’s probably a extremely rare thing to happen, but it does happen.
One wonders is this also a timely reminder to keep those connectors lubed, and not allow them to become rusted and difficult to use and quite possibly more prone to failing.
Anyway it’s far easier to push home securely both the red and yellow (if pressurised) connectors if lightly lubed, try it sometime.
Same goes for lots of things on our vehicles, hinges locks linkages cables etc even the fifth wheel clip, generally they won’t get lubed on a service and the ever more common cry of ‘‘it aint my job’’ (in that surly adolescent girly way the usual suspects object to doing anything remotely useful 
) really is cutting their own nose off to spite their face.
I love working easily with moving parts lubed clean and working well and with clean air and electric lines and catwalk, takes a matter of minutes now and again to nip round your vehicle with some spray grease or similar and even if no access to a hot water pressure washer get some blue cloth and clean the air lines and catwalk area up.
Won’t suggest checking and if necessary slapping some grease on the fifth wheel between services or they’ll be fainting in the aisles 
Ontop of putting park break on, I turn my engine off which in a e handbrake will automatically put the brake off
Juddian:
One wonders is this also a timely reminder to keep those connectors lubed, and not allow them to become rusted and difficult to use and quite possibly more prone to failing.
Anyway it’s far easier to push home securely both the red and yellow (if pressurised) connectors if lightly lubed, try it sometime.Same goes for lots of things on our vehicles, hinges locks linkages cables etc even the fifth wheel clip, generally they won’t get lubed on a service and the ever more common cry of ‘‘it aint my job’’ (in that surly adolescent girly way the usual suspects object to doing anything remotely useful
I love working easily with moving parts lubed clean and working well and with clean air and electric lines and catwalk, takes a matter of minutes now and again to nip round your vehicle with some spray grease or similar and even if no access to a hot water pressure washer get some blue cloth and clean the air lines and catwalk area up.
Won’t suggest checking and if necessary slapping some grease on the fifth wheel between services or they’ll be fainting in the aisles
dont get me started about preventative maintenance. The unit i had the other night almost needed two hands to yank the drivers door open where the hinges/ check strap were soo stiff. Went and asked if they had some white grease and just got a blank look. to be fair it wasnt thier unit it was one of the agency units thats kept there.
cooper1203:
Juddian:
:dont get me started about preventative maintenance. The unit i had the other night almost needed two hands to yank the drivers door open where the hinges/ check strap were soo stiff. Went and asked if they had some white grease and just got a blank look. to be fair it wasnt thier unit it was one of the agency units thats kept there.
That’s something i’ll never understand, every day someone has had to kick the door open and force it to close, its usually Scanias, for the sake of a squirt of oil or grease
You just know sooner or later the key will break off in the doorlock because that’s never seen a drop of lube in its life either.
Why? can anyone give a reasonable explanation of what they gain out of working multiple times harder than necessary say in day for teh sake of a drop of oil, cos i’d love to know the reasoning involved.
And why isn’t there such lube available in each and every traffic office throughout the country, please don’t anyone mention having to be trained in the use of a bloody tin of aerosal grease.
Im confused.com just watched a short video on how air brakes work. This video said at rest with no airlines connected the cam is held in the “brakes on” possition by a spring. Along comes someone and connects up the red airline which provides air to the workings and overcomes the sprung force and rotates the cam to the “brakes off” position so we have aprox 12 bar holding the brakes off. I get that. what i dont get is the yellow line that seems to work in the oppersite way ie pressure on the line = brakes on no pressure = brakes off. I can seethat pressing the foot brake could activate a valve of some kind of what ever it does to allow the air through to the brakes for whant of a better phrase but unless we live in some alternate universe where the laws of physics dont apply there has to be a force greater than 12 bar applied as there is 12 bar on the red airline holding the brakes off which there cant be as the air for both lines comes off the same tanks. Even if it was seperate tanks the gauge in the cab is always showing the same pressure once its all charged.
Juddian:
cooper1203:
Juddian:
:dont get me started about preventative maintenance. The unit i had the other night almost needed two hands to yank the drivers door open where the hinges/ check strap were soo stiff. Went and asked if they had some white grease and just got a blank look. to be fair it wasnt thier unit it was one of the agency units thats kept there.
That’s something i’ll never understand, every day someone has had to kick the door open and force it to close, its usually Scanias, for the sake of a squirt of oil or grease
You just know sooner or later the key will break off in the doorlock because that’s never seen a drop of lube in its life either.Why? can anyone give a reasonable explanation of what they gain out of working multiple times harder than necessary say in day for teh sake of a drop of oil, cos i’d love to know the reasoning involved.
And why isn’t there such lube available in each and every traffic office throughout the country, please don’t anyone mention having to be trained in the use of a bloody tin of aerosal grease.
Years ago I did some work experience in a garage as a matter of course when ever a car came in for a service even if it was justa oil and filter job we would go round with a can of white grease and spray all the locks hinges and striker plates. We had some silly lady complain that she had managed to get the sleve of her dress covered in it because there was this white stuff all over her car that wasnt there when she brought it in.
You can just imagine the fairy driverss that moan if they break a finger nail being up in arms if there was a speck of grease on thier clothes if they are too inept to get in and out of the vehicle properly.
cooper1203:
Im confused.com just watched a short video on how air brakes work. This video said at rest with no airlines connected the cam is held in the “brakes on” possition by a spring. Along comes someone and connects up the red airline which provides air to the workings and overcomes the sprung force and rotates the cam to the “brakes off” position so we have aprox 12 bar holding the brakes off. I get that. what i dont get is the yellow line that seems to work in the oppersite way ie pressure on the line = brakes on no pressure = brakes off. I can seethat pressing the foot brake could activate a valve of some kind of what ever it does to allow the air through to the brakes for whant of a better phrase but unless we live in some alternate universe where the laws of physics dont apply there has to be a force greater than 12 bar applied as there is 12 bar on the red airline holding the brakes off which there cant be as the air for both lines comes off the same tanks. Even if it was seperate tanks the gauge in the cab is always showing the same pressure once its all charged.
Try this one Cooper youtube.com/watch?v=A8kQ-vABYQ4 spring brakes well explained from 2 minutes on but the whole video is worth 10 mins of your life.
Juddian:
cooper1203:
Im confused.com just watched a short video on how air brakes work. This video said at rest with no airlines connected the cam is held in the “brakes on” possition by a spring. Along comes someone and connects up the red airline which provides air to the workings and overcomes the sprung force and rotates the cam to the “brakes off” position so we have aprox 12 bar holding the brakes off. I get that. what i dont get is the yellow line that seems to work in the oppersite way ie pressure on the line = brakes on no pressure = brakes off. I can seethat pressing the foot brake could activate a valve of some kind of what ever it does to allow the air through to the brakes for whant of a better phrase but unless we live in some alternate universe where the laws of physics dont apply there has to be a force greater than 12 bar applied as there is 12 bar on the red airline holding the brakes off which there cant be as the air for both lines comes off the same tanks. Even if it was seperate tanks the gauge in the cab is always showing the same pressure once its all charged.Try this one Cooper youtube.com/watch?v=A8kQ-vABYQ4 spring brakes well explained from 2 minutes on but the whole video is worth 10 mins of your life.
i know im a sad git but i find all this intresting
Nothing sad at all about learning this stuff, good to see someone interested. 
Juddian:
[
Try this one Cooper youtube.com/watch?v=A8kQ-vABYQ4 spring brakes well explained from 2 minutes on but the whole video is worth 10 mins of your life.
I love how he looks down the barrel of the gun at 4:25 in case another spring is coming out [emoji23]
Nice one Juddian [emoji106] So will most of the wheels have spring brakes rather than just service brakes?
stu675:
Juddian:
[
Try this one Cooper youtube.com/watch?v=A8kQ-vABYQ4 spring brakes well explained from 2 minutes on but the whole video is worth 10 mins of your life.I love how he looks down the barrel of the gun at 4:25 in case another spring is coming out [emoji23]
Nice one Juddian [emoji106] So will most of the wheels have spring brakes rather than just service brakes?
Some older trailers don’t have spring brakes, you can tell them because they have a ratchet cable handbrake
stu675:
Juddian:
[
Try this one Cooper youtube.com/watch?v=A8kQ-vABYQ4 spring brakes well explained from 2 minutes on but the whole video is worth 10 mins of your life.I love how he looks down the barrel of the gun at 4:25 in case another spring is coming out [emoji23]
Nice one Juddian [emoji106] So will most of the wheels have spring brakes rather than just service brakes?
I believe, but happy to be put right and people like Cav, Norb or Punchy Dan would know better cos they get mucky down in the business end of things and will know what they’re talking about, that the typical 3 axle semi trailer will have two axles fitted with spring brakes.
Whether thats a standard or minimum and you could have all 3 axles so fitted i don’t know, i know the few times i’ve run through VBT (voluntary brake tests) in recent years that when it comes to the park brake then only two of the trailer axles are tested, and pretty sure only two of the three axles on my trailer are spring brakes.
Just thinking out aloud here, that maybe one axle is kept on standard non spring brakes so in the event of the red line snapping or other air failure and the spring brakes applying automatically, that the axle which kept rolling would help prevent the whole trailer slewing sideways as it could easily on a wet road if all axles locked…as i say that’s pure supposition on my behalf, i’m not a qualified truck mechanic by any means just a basic bodger 
Would welcome a full explanation of what’s going on and why from the mechanics and OD’s who work on these things.
I can confirm the twin Axel trailers I use both have springs.
4 of…
What about the unit? Will the handbrake just be on the drive axel or steer?
where all the tyres like that ^^^^^