1990 Johnson Evinrude "ES" Cross V 88 thru 115, 150 thru 175, P/N 507874, Page 346Get this manual
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bQuickly clamp the piston tightly in soft-jaw vise Using breaker bar or similar tool through the eyelet, unscrew the rod from the piston Allow the piston to cool before removing from the vise The four valves in the tilt piston are not serviceable If the valves need replacement, the entire piston assembly will have to be replaced Remove any Locktite material left in the threads of the piston and the rod cSlide the tilt cylinder end cap off of the rodRemove and discard the outside O-ring from the end capUsing flat toolpry the outside scraper from the end capDiscard the scraper
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dUsing the same tool, pry the O-ring and back- up ring from the end cap Discard the O-ringeOil and install new O-ring and back-up ring in the end cap The square back- up ring goes above the 0ring