1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 258Get this manual
4Install pinDrive pin in until flushInstall Power Trim assembly on engine, refer to "Installation" instructions in "Power Trim Assembly Removal and Installation," preceding Tighten manual release valve to full right (clockwise)Operate trim motor in "Up" direction by connecting trim motor wires to 12-volt battery [BLUE wire to POSITIVE (+) terminal and BLACK wire to NEGATIVE () terminal]Slowly remove fill screw to bleed pressure from reservoir
From full closed (clockwise) position, slowly turn manual release valve counterclockwise four turns to bleed remaining pressure from systemRemove bolts and lockwashersLift motor and pump assembly from housingINOPERATIVE TRIM MOTOR Slowly remove fill screw to bleed pressure from reservoir51356
aPin (Drive Against Knurled End)
Pump Replacement