outdrive rises thru winter

[bones774]

hi, getting ready to winterize boat for the northeast winter. Over the years I always put my outdrive in down position for the winter by the time the spring comes around the outdrive is fully up.
Any ideas or suggestions thanks

 

[Rick Stephens]

Change the trim oil - it has water in it.

 

[Grub54891]

^^ yes to the above. It will damage the pump or Crack the rams if left with water in there.

 

[kenny nunez]

If there is no water in the system then what is happening is the heat from the sun will build up pressure gradually over time.
The Mercruiser instructor mentioned that running the drive up until you hear the pump sound like it is straining will leave 3k psi on the system and the sun will raise it to a point that one of the hoses will start to leak. This was on the earlier Prestolite system and not as bad on the Oildyne low pressure style.