The green passenger sphere (also with a citroen Logo on) did not allow any movement of the suspension it was rock hard!!! only the tyre sidewall allowed movement.
So lowered the car all the way down decompressed the system.
I had an oil filter removal tool that I bought this morning for £9 ... and it did a magnificent job first attempt.
When I unscrewed the sphere by hand it squirted a bit of fluid and then it was ok. The seal came out with the sphere I was under the impression the seal ring should have stayed inside the pipe for me to remove.
The new sphere is colour green as well and with a new seal, I installed the new seal in the pipe as it was meant to be nice and flush, then screwed the new sphere.
Switched on the engine ... a few up and downs ... topped up the suspension LHM Fluid with Total Plus. And all worked brilliant.
The suspension is now working brilliant... a bit more soft compared to the H3+ ofthe C5
But then I guess is will be
