Thanks for reply.

Its a metal pipe. If you carefully fit pipe in with seal and bleed system and pump peddle - all ok.

Left van overnight and looked for leaks today. Clean. However, when I started the vehicle up, the fluid has then started leaking - because of movement on the pipe?

The vehicle only came in as clutch peddle retaining pin had broken - no leaks whatsoever.

Leak only now since fitting brand new Cylinder.