In case anyone is interested. I called Merc today and they said the pressure test info was in the technicians guide, not the service manual.
Pressure to 7-10 psi 5 min.
Rotate driveshaft, prop shaft, move shift rod.
Pressure to 15-16 psi 10-15 min.
Rotate driveshaft, prop shaft, move shift rod.
Check for leaks if pressure drop noted.
Vacuum tests are not recommended due to design of labyrinth seal.
