Not losing any fluid, pump works when opening the door, sometimes it refused to start pumping but freed up when given a gentle tap or when the bonnet is dropped back down from being open.
I ran a test today monitoring the hydraulic pressure which when the engine not running it slowly decays back to the pump cut in at 43bar, pump brings it back up and it will sit for a while again slowly decaying. So something in the circuit is allowing the pressure to fall.
If the membrane within the accumulator failed would this not just allow more fluid to enter that space which would be evident in a drop in level at the reservoir.
I have a replacement accumulator so i'll fit it and see how things go from there. My last loss of gears was down to the accelerator pedal potentiometer giving a bad signal back to the ecu. I've cleared the error code and will look out for that again.
Thanks for the advice.