Mercury Mariner 30/40 4-Stroke Outboard Service Manual 1998, Page 347Get this manual
MANUAL TILT ASSIST
2Check for external leaks in the manual tilt systemReplace defective part(s) if leak is found
IMPORTANT: If cut or damaged o-rings are found, inspect machined surfaces for scoring, burrs or debris3Check for discharged accumulator35 to 50 Ib-ft (47-68 Nm) of pulling force must be attained when tilting outboard from full "down" to full "up" positionIf more than 50 Ib-ft (68 Nm) of force is required, replace accumulator