1995 Johnson/Evinrude Outboards 50 thru 70 3-cylinder Service Manual, Page 304Get this manual
Trim-OUT!Tilt-UP Mode
When operating the hydraulic unit in the Trim-OUTlTilt-UP mode, hydraulic fluid is routed in the following manner:
1Hydraulic pressure is directed to the trim check valve side of the pump control pistoncausing the piston to open the reverse lock check valve 2The trim check valve then opens against very light spring tension and the fluid flows to the base of the trim cylinders3Additional hydraulic fluid opens the tilt check valve and flows to the base of the tilt cylinder4Fluid returning from the top of the tilt and trim cylinders is directed through the open reverse lock check valve and back to the pumpIt is important to note that all fluid on the return path returns to the pumpBecause the trim and tilt rods displace fluid at the top of the cylinders, the fluid returning to the pump through the reverse lock check is not sufficient to supply the pump, so additional fluid is drawn from the reservoir5When both the trim and tilt rods are fully extended and the pressure exceeds 1500 psi (10500 kPa), the trim-up relief valve will open, directing the fluid to the reservoir6When the hydraulic unit is trimming outtilting up or when the engine is running in forward gear, the following valves must hold pressure: Tilttrim separation valve Trim check valve Expansion relief-valve Trim cylinder O-rings Trim -up relief valve Tilt check valve Tilt cylinder piston and O-ring