1995 Johnson/Evinrude Outboards 40 thru 55 2-Cylinder Service Manual, Page 299Get this manual
Component Description
UP CHECK VALVEWhen opened by pump pressure, it directs fluid to bottom of cylinder to move piston UPWhen opened by pump control piston, it allows low pressure fluid to return to the pump as the piston moves DOWNMANUAL RELEASE VALVEWhen opened minimum of three turns, it allows the engine to be manually raised or loweredDOWN CHECK VALVEWhen opened by pump pressure, it
t=J directs fluid to top of cylinder to move piston DOWNWhen
opened by pump control piston, it allows low pressure fluid to return to the pump as the piston moves UP
rJl PUMP CONTROL PISTON
Moved by pump pressure, it controls the UP and DOWN check valvesTogether, they control fluid direction and cylinder movementDOWN RELIEF VALVEOpens at approximately 1600 PSI (11,032 kPa) to protect the unit from extreme operating pressures when the cylinder is completely retractedEXPANSION RELIEF VALVEProtects the unit from extreme pressures caused by thermal expansion of the fluid