1998 Johnson Evinrude "EC" 25, 35 HP 3-Cylinder Outboards Service Manual, Page 260Get this manual
DOWN 1When the DOWN button is pressed, the pump
rotates in clockwise direction
2Fluid pressure opens the DOWN check valve opening the UP check valve
and moves the pump control pistonmechanically
3Fluid pressure is directed to the top of the cylinder to move the piston DOWN4Low pressure fluid leaves the bottom of the cylinder, moves through the open UP check valveand returns to the pump CD
5To allow for the volume differential caused by the piston rod, excess fluid is vented to the reservoir through the DOWN relief valve 6When the piston is completely retracted, pump output is vented to the reservoir through the DOWN relief valve to protect the unit from extreme operating pressures7When the unit is operated in the DOWN direction or when the engine is running in REVERSE gear, the following components must hold pressureImpact relief valves Up relief valve Piston a-rings Q) Down check valve Filter valve and seat Manual release valve