1985 Merc ELPTO Power Trim leaking down

[stevenmike]

Like the title says. My power trim is leaking down. No visible external leaks, ensured reservoir is full and cycled trim to each extreme several times to clear any trapped air.
If I trim up most of the way and push on the motor it falls with some effort till it hits the short rams then stops. If I let it sit on the short rams it slowly leaks down.

When on the water under power it leaks all the way down in a few seconds.

Suggestions to check? Thanks

 

[jimmbo]

Is the manual Valve on the Transom Bracket fully closed?

 

[stevenmike]

Removed it checked o rings for damage and reinstalled. Also checked fluid levels.