1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 328Get this manual
8Remove rod wiper, inner O-ring and outer O-ring
51146Spanner WrenchTrim Rod Piston
CAUTION
Do not remove check ball components (a) from trim rod pistonRemoval and re-installation of check valve could result in improper operating pressure and possible power trim system damageIf check valve is defective, replace trim rod piston7Remove inner O-ring from piston51145