1995 Johnson/Evinrude Outboards 50 thru 70 3-cylinder Service Manual, Page 267Get this manual
Trim-OUTITilt-UP Mode 1When the UP button is pressed, the trimtilt motor rotates clockwise (as viewed from pump end) and turns the pump gears2Fluid pressure passes through the UP shuttle valve to the DOWN shuttle valvewhich mechanically opens the DOWN check valve 3Fluid pressure pushes the UP check valve off its seat and fluid passes through the valve to the bottom of all cylinders, pushing the pistons UP4Fluid is pushed from the top of the tilt cylinder by the piston and returns through the open DOWN check valve to the pump5In the trim range, fluid is pushed from the top of the trim cylinders Q) by the pistons and returns to the reservoir6Only fluid from the top of the tilt cylinder is returned to the pumpBecause the cylinder rod displaces some fluid, that volume is less than the volume of the bottom of the tilt cylinderSo, additional fluid is drawn into the pump from the reservoir7When all the cylinders are completely extended, the pressure increases until the UP relief valve opens at the tilt-up stall pressure (approximately 1500 PSI)