Mercury Mariner 30/40 4-Stroke Outboard Service Manual 1998, Page 23Get this manual
MAINTENANCE
Checking Power Trim Fluid
t Tilt outboard to the full up position and engage the tilt support lock2Remove fill cap and check fluid leve1The fluid level shou ld be even with the bottom of the fill holeAdd Quicksilver Power TrimSteering FluidIf not avai lable, use automotive (ATF) automatic transmission fluidFill Cap
Changing Engine Oil