1987 Johnson/Evinrude CU Outboards 35A thru 55 Service Manual, Page 316Get this manual
Removal of Pump Motor 1Using the trim switch, run the unit down completelyLoosen the manual release valve
one full turn
3Momentarily jog the trim switch "up," then "qown," then
" up" Failure to follow step below could result in eye injury to you or bystander4Some residual pressure may be present in the hydraulic system when the manual release valve is removedRemove the manual release valve watching for residual pressure tending to push valve outAlways pack shop rag or towel around the screwdriver shank and against the manual release valve access hole in the stern bracket when removing the manual release valveThis will trap squirting fluid as the manual release valve is removedCatch lost oil with rag and drip pan