I'm looking to change the old fluid in my power trim system. It currently has motor oil in it. Volvo manual states motor oil or recommended ATF. Is there a good way to purge the old motor oil out before switching to ATF?
anything wrong with the oil that is in there? its also the same fluid you have in your power steering and the motor (SAE 30 weight). which is what was recommended during the time your boat was made.
the hydraulic pump doesnt care, unless the oil is bad (water contamination), why should you?
If you change now: you might cause the seals to leak?
For some reason there is a possibility the seals can go bad when you change oil.
It doesn't happen all the time but if it does changing back won't fix.
You'll have to re-seal.
the oildyne 108 hydraulic pump will run on anything from vegetable based hydraulic oil to mineral based hydraulic oil to atf to motor oil with viscosity all over the map). they are all equally recommended by oildyne / parker. the recommendations from Mercruiser and Volvo have changed over the years.
