question Air Brake Connections on rear of lorry/tractor

[rustexpert]

Just a quick question; someone here will know of the top of their heads, don't know where to find information like this. I suppose mostly you don't need to know, as you just go with the existing is correct.

However I have a vintage Foden with air brake connectors on the back for a trailer;

there is a red pipe which is constant pressure with a male connector and a yellow pipe which is pressure only when the pedal is down (brakes on) and has a female connector.

The scant information I have is that these connectors are for whatever reason in a non conventional state and should be reversed to be "normal".

The tractor was used on a trailer but probably that one only ever so if the connections were reversed it wouldn't matter.

Please discuss.

[John Comber]

Just a quick question; someone here will know of the top of their heads, don't know where to find information like this. I suppose mostly you don't need to know, as you just go with the existing is correct.

However I have a vintage Foden with air brake connectors on the back for a trailer;

there is a red pipe which is constant pressure with a male connector and a yellow pipe which is pressure only when the pedal is down (brakes on) and has a female connector.

The scant information I have is that these connectors are for whatever reason in a non conventional state and should be reversed to be "normal".

The tractor was used on a trailer but probably that one only ever so if the connections were reversed it wouldn't matter.

Please discuss.

 

Red line is the emergency supply , on proper lorries which had air taps before suzies , the connector at the cab end is female, the red suzie to connect a trailer is female ended at the trailer end.

The yellow line is the service line ( brake pedal operated ) this is the opposite so has a male connector fitted on the lorry , with the suzie being male ended to the trailer side..

with that configuration you will be compatible to all trailers new and old.

So from your initial description , yes the connectors on the unit pre suzie need swapping round.

[rustexpert]

 

This is as it is; it is not intended to be traditional style. Should the couplings be swapped?

If the coiled air pipes have a coupling on each end; so they are removable from the trailer. Do they have different male/female couplers each end or same each end?

This might seem a daft question/subject but cant find anything covering this on the net; any searches come up with places which sell parts or yank websites.

It is probably best to find a local haulage firm with a mechanic to ask.

[cosrec]

thats how its work for as long as i remember red supplies air to release brakes yellow supplies signals to tell brakes what to do

[rustexpert]

thats how its work for as long as i remember red supplies air to release brakes yellow supplies signals to tell brakes what to do

Yes but I only want to know which coupler goes where; is the picture right or wrong?

[Adrian Barrell]

The picture is wrong, they should be swapped. I would also fit some blanking plugs, insects like to make homes in pipes and couplings. Not a big problem if you never tow a trailer but annoying if you do and end up blowing debris down your lines!

[rustexpert]

The picture is wrong, they should be swapped. I would also fit some blanking plugs, insects like to make homes in pipes and couplings. Not a big problem if you never tow a trailer but annoying if you do and end up blowing debris down your lines!

Thanks another informant has told me that the original owner only had the one trailer for this tractor and the pipes being the wrong way round would never have been an issue. I am intending to recommission the brakes on a trailer (that is another topic). Is it a usual precaution to blow out the coiled pipes every time you use them? Is debris in the lines a big problem? I just have no practical experience with air brakes on road vehicles.