2001 Mercury Mariner 50-60HP Factory Service Manual, Page 347Get this manual
POWER TRIM
8Inspect check valve for debris; clean debris from check valve if foundIf debris cannot be cleaned from check valve, replace shock piston as an assembly9Clean shock and components with compressed air10Remove inner o-ring from shock rod pistonaShock PistonO-ring
11Remove cylinder end cap assembly from shock rod12Inspect shockIf wiper (located in cap) has failed to keep rod clean, replace wiper13Place end cap on clean work surface14Remove rod wiper, inner o-ring, and outer o-ring