Hallo Tage!
Yes for shure it was time to change
oil filter, but I shuld recommended
you to tapp out oil tanks for cleaning.
I have Just don that in my Hymac 580 BT and ther was lot of smack on tank walls and in the botom it was metalic/crome peaces that I piced up
I cleaned all three tanks and at the same time a modify whit tow big magnet capsuleted in stanless steal that will pic up metall, I bought them on SYSTEM Verktyg Älvsjö Stockholm
Placed one on the main thank middel wall and the oder one in suction tank middel wall
I hope that will safe the pump a litel
But now I hade problem whit hydralic filter Catridge it will not come off it stucked
But good luck whit your filter changes