1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 393Get this manual
drop off no more than 700-1400 kPa (100-200 psi) after the motor is stoppedIf the gauge reading continues to drop, leakage is indicated in the trim up relief valve, impact letdown valve, tilt check valve, tilttrim separation valve, trim check valve, shock absorber valves, expansion relief valve, or at the shock absorber piston sealTo test in the "down" direction with gauge "B", run unit down until fully bottomed outIf the gauge reading drops more than 700-1400 kPa (100-200 psi) after the motor is stopped, leakage is indicated in the impact sensor valve, filter valve, reverse lock check valve, shock absorber valves, or seals on trim rods or tilt piston rod 93312
Valve Leakage Test If any of the check valves are suspected of leaking after the pressure test checks are completed, check of each valve should be madeThis can be accomplished by using Check Valve Tester PIN 390063 and Stevens Gearcase Tester Number S-34 or equivalentTest Procedure
Either the short or the long check valves