Thanks for all replies, including Tony who rang me up.
Took drv out of rear of high pressure pump, noticed quite a lot of wear on valve behind rubber o ring.
Have spoken to guys at Electrotec who suggested testing pump as I mentioned in previous post, not sure what you mean by blind pressure test, Pete.
Can landrover dealer tool give actual pressure, or is this again only what is percieved by the rail switch?
Must get back onto this one this week as it has been with us some time now, thanks for all replies, loking forward to some good news soon, Phil.