Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 186Get this manual
4Secure gasket (a) and cover (b) to bracket (c) using bolts and washers (d) Filling and Bleeding the Power Trim System
Checking Oil Level and Filling
IMPORTANT: Check oil level in pump only when engine is fully tilted upPump reservoir must be vented for pump to operate properly1Open pump vent screw (a) turns2Turn manual release valve (b) full left (counterclockwise)