1990 Johnson Evinrude "ES" 40 thru 55, P/N 507872, Page 308Get this manual
1221 22Remove five impact relief valve balls1231 23Remove up relief valve1241 24Remove the valve housing and washer from the
Discard the internal a-ring
1251 25Remove and discard the quad ring and two backup rings1261 26Slide the end cap off the rodDiscard the scraper1271 27Removethe internal a-ringDiscard both internal and
external a-nngs28Clean the manifold thoroughly in fresh solventBlow excess solvent from the internal passages with compressed airIt is essential that the manifold and all components be kept absolutely clean and dust freeAny dirt in the system could cause scoring of cylinder bores, sticking valves, or damage to pump components