qbond

Thanks, this explains how and why you dont need to put in a power steer box, if the valve goes in the drag link, just like the air-o-matic system. The primary vehicle is a Jag Mark 1 which has had a bigger/heavier engine fitted. Unfortunately, there is no drag link, as the Pitman arm attaches direct to the track rod and the rod to the wheel. I wanted to get an air control valve to mount inside the car to provide assistance for parking/reversing but not general driving - but the idea seems to be dead in the water as while I am happy to have an air line in the cabin I am not so keen on hydraulic lines.