Well this problem could probably have been predicted! The outlet of the supercharger is quite close to the power steering fluid reservoir and obviously the supercharger outlet gets quite hot so on a few occasions the power steering fluid overflowed a little, I assume just due to it expanding with the heat and it was filled right to the max level which wont have helped.
So I wrapped the reservoir with some gold heat reflective tape.
Knowing the fluid had got quite hot a few times and probably hadn’t been replaced for along time, I put some new fluid in and filled it to the middle of the level.
Old out. Not gonna bother trying to drain it at the bottom.
After a few more journeys it had clearly done the job as no more overflowing problems. 🙂