ARB compressor

no John its normal, I have seen the hoses fitted with a simple cutoff switch, but I just bend mine at the end and that stops the hiss while I change it from one wheel to the other, the cutout and small reservior is used when the ARB compressor is used for their air lockers.

John the quick connect coupling that is fixed to the compressor has an inbuilt check valve, hence when you disconnect the hose it is sealing the outlet allowing the pressure to build up within the system and the pressure switch cuts out.
Hence stopping the compressor from exceeding the maximum working pressure.

When you plug the hose in it is leaking from the tyre valve coupling ? is the way I understand you, hence it leaks and the pressure does not build up to the cut off point.
The short answer is simple, don't worry about it they all leak mine included.

The amount of air lost is minimal and the effect it will have on your tyre filling situation is so small it's not worth worrying about.

I have a 6m snap on hose on my ARB comp with a valve inflation fitting and a blow down gun (for cleaning) - no leaks - bought the hose and bits from Beissbarth (they are into supply of goodies for the tyre changing industry). I can leave my hose laying about for ages with either of the tools on the end and the compressor stays off at 100psi for a long time. Don't know if the hose sans tools actually leaks - with a tool in there, its fine.

John,
Although I don't actually use a ARB compressor any more, the principal is the same on my Max-Air controlled system......I use an air hose with "Ryco" brand snap fittings both ends. That way, the air flow stops if there is no fitting in the end of the hose. Into the female fitting at the end of the hose (where the air comes out), I use a quick connect fitting that has a sort of "dome" shape which is the bit that goes onto the tyre valve. It has a trigger which needs to be squeezed to enable putting onto or taking off the tyre valve. Unless it is actually on the trye valve, it will not permit air to escape....they cost about $10- from most air supply type places. Very simple and effective. The quick connect set-up also enables me to fit a blow-down tool or rattle gun or what ever other sort of air tool i need.

I just put a switch on mine of an old 240v lamp i through out.

I have a Blue Tounge with an ARB pressure switch on it and I simply went down to hoscoe and bought a small air tap, cut the end of my hose about 10cm back inserted the tap and now I can turn it on to pump up tyres, then when done turn the tap off and it goes back to charging the tank and lines while I stuff around moving over to the next tyre. It'll cost you less than $10.
Sure I have a quick connect on the car which automatically shuts off when I disconnect my hose too.
The problem I found was that tyre infators that seal at the end generall don't latch onto the valve, you have to hold them there (like a servo setup). I still wanted to be able to clip my hose onto the tyre valvue and walk off while it pumps up, that's why I went the tap.