Hydraulic fluid is hydraulic fluid.
Yep. hightec the viscosity is important'
10 w is pretty standard.
Used 10 w in many Vetus hydraulic pumps.
LaTouche, go to your nearset 'Partco' or motor factor.
Cheaper than Halfords, not that you will need much.
Deffo you don't need 'Vetus' oil or owt fancy
When I was looking to top up my Linear actuator, I was told that I could use brake fluid and all sorts of other stuff. Yes it is possible, and you can use water or vodka too (in an emergency). Hydraulic fluid comes in different grades, from really thin stuff to thick stuff. Common grades are SAE 46 and SAE 68, OK for a JCB or other plant, but not so good for an autopilot where a responsive system is needed. I'm in Spain (Canaries) at the moment and I needed SAE 32, this is like gold dust here. Anyway I managed to find some. Use what the manufacturer recommends, you will probably need some pretty thin stuff if you're in the UK, but not too thin, else it will leak past your seals.