1980s Johnson Power Tilt/Trim wont stay up.

[JustWarminUp]

Looking into possible reason why my Tilt/Trim wont stay up.

It goes up when I want and down when I want.

However if I put it up it will be down in 4-5hours.

I attached a relative picture of the type I have.
Took out the manual bleeder screw, o ring was good and tightened respectively with no change.

 

[JustWarminUp]

 

[Faztbullet]

Valve body problems

 

[JustWarminUp]

Is there any additives anyone has tried to run through these to refresh any seals or clean out passages?

Is the valve body made up of rubber seals and flaps or metallic mechanical valves if anyone knows?