I think I may have got to part of the reason for my coolant loss, On the coolant bottle I removed the pressure cap top clean ( just to make me feel better :-) ) and noticed on the top it is marked as 22 psi. From peoples replies the system should be pressure tested to 15 psi. I would guess that with this cap not releasing the pressure correctly in is forcing the coolant out through a rubber joining pipe. What do you think Paul #6463 www.paul.salsbury.btinternet.co.uk