Ok, so I've been searching without joy - my valve block is corroded and leaking where the pipes connect. I've fitted new seals, which have reduced the amount of fluid I'm buying, but not cured it. I want to keep the system but a new valve block is £1000!!! Has anyone machined a block to enable the pipes to seat better? I'm concerned that the filings would penetrate the valves and screw it completely. Thanks in advance.