Bad calibration of INDININI’s auto pilot controller resulted in an over steer by the ram forcing out some hydraulic fluid. This caused air in the fluid and autopilot steering became very unresponsive. By the time adjustments were made to correct course, I had already disabled the autopilot and was hand steering.
INDININI has a B&G T2 ram which in fact is a hy-pro drive. Looking for a litre of the correct fluid took more time than expected so I wanted to post a quick note here.
The fluid as defined on in the link above for the ram is:
SO VG10 to VG40 hydraulic mineral fluid to ISO 6743-4 HV
Hy-pro have listed Q8 Dynabear 10 as the proposed hydraulic fluid on the website, but at the time of writing, the “Purchase this product online” could not be bought online. Searching for the name only resulted in options to by 45 gallon drums.
It seems others in forums had run into the same issue, and I also didn’t find anyone who had a solution. It looked like it was time to research and understand what the codes meant.
VG10 to VG40 in simple terms refers to the viscosity. There is actually more to it than that relating to density etc but for the purpose of finding the right one, we just need to find one between 10 and 40. There are many options for 32.
Next step is to understand the ISO 6743-4 HV. This is the relevant section of a document describing the different classifications.
More searching including asking ChatGPT for the exact HV version resulted in either large quantity or sales outside of Europe.
There is a place in Germany that sold 1L bottles with almost the correct classification. ATO24.de has an HLP version which is very close to the HV.
If anyone has other options please send me note and I’ll update the details here.