2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 178Get this manual
GEARCASE WATER PUMP
WATER PUMP
Disassembly
Remove the four screws retaining the impeller housing to the gearcase
this groove is blocked by adhesive, the pump will lose its prime and not pump water1 -:-1
1Seal ring groove 2Ribs 3Air bleed groove 1Impeller housing screws
Install the O-ring in groove in the impeller housing Slide the water pump off the driveshaftRemove the impeller drive cam, impeller plate, and impeller plate gasketDiscard the gasket
1Impeller plate 2Drive cam
Lightly coat the exterior of the impeller cup with Gasket Sealing CompoundInstall the cup in the impeller housing The cup locks in place in the housing with square index tab