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Lower unit pressure

michael_l

michael_l

Member
I have a 1996 Johnson 30 hp motor that was getting a little water in the lower unit. I replaced the water pump and related seals, o rings on the fill and vent openings and performed a bench pressure test. It dropped from 13 pounds to 12 pounds over 30 minutes. Would that drop be considered acceptable? Thanks, Mike
 
I like to test them overnight ------------Like to see no drop in pressure.------------------------Submerge the unit in water or use soapy water to see if you can find the leak.
 
I sprayed the suspect areas with a soapy solution but saw no evidence of a leak. I will try the submersion method. Thanks, Mike
 
Last edited:
Found the leak. It was the pressure tester! So far 12 hours rock solid at 13 pounds. Original leak must have been through the vent or fill hole and fixed with new O rings.
 
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