1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 392Get this manual
Troubleshooting With Pressure Tester
The OMC Trim and Tilt Pressure Tester PI 390010 provides method of checking for hydraulic leakage of valves and seals One gauge is used for pressure measurement in theup" mode of operation and the other gauge is used for "down" operation Measurements can be made with the unit mounted either on the motor or on the bench1To install gauges remove the manual release valve remove the valve: aRemove retaining ring 303857 (Truarc Pliers)bc
with OMC Special Tool PIN
Using the trim switch, run the unit down completelyLoosen the manual release valve one full turn
d Momentarily jog the trim switch "up," thendown," then "up eRemove the manual release valve watching for residual pressure tending to push valve outFailure to follow step below could result in eye injury to you or bystanderfSome residual pressure may be present in the hydraulic system when the manual release valve is removedAlways pack shop rag or towel around the screwdriver shank and against the manual release valve access hole in the stern bracket when removing the manual release valveThis will trap squirting fluid as the manual release valve is removed