Barry 10

Do you mean brake air? I had the same problem on my 84 until i pushed the trailer supply button on the dash, I assumed the air would already be there as it was plumbed up for a tag trailer when i bought the truck. If thats not the problem i will go take some pics of how mine is setup for you.

Thanks for that, yes I do mean brake air, and today I shall look for a 'trailer supply button', although can't picture where that may be on the dash.. again thanks and at the end of the day I'll let you know how I've progressed.

I am trying to hook air up to dog trailer and not able to get air through to rear of truck. I have put a new valve half way down chassis to supply both lines, because existing valve had seals etc that were no longer useful/serviceable.

Is anyone able to advise where to look next.....please

Thanks Barry 10