Re: 88 Johnson Tilt Question -
Never heard of that one before.
Does it make the same sound?
I would try unscrewing the manual release valve 2 full turns and cycle it through full tilt by hand to bleed it a few times, top up the fluid , tighten release valve to 45in lbs torque and try again.
If you find the tilt system no longer functions the release valve is too loose, put a wrench on a BIG screwdriver to tighten it good.