Indeed but most people would never use 5 ltrs so the initial outlay is prohibitive. You could try a local compressor place, they might let you have what you need for kitty money.
I have been told it is more than likely the valve plate that is causing the problem,anyone have a clue how much that is likely to cost and is it a big job to replace it ?
I have been in contact with jun air who say it is more than likely the valve plate.But it's only available from them as part of a service kit at £120 ish,i don't think it's worth spending that much on it,i'll look for a bigger used compressor instead