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1996 70 hp johnson prop shaft seal replacement

kehhu

New member
I have water in the lower unit do I need to replace all prop shaft seals or just the outer one can i replace it or them with out taking apart the lower unit do i need special tools to do so i will be replacing the water pump also should i replace upper drive shaft seal while it is apart and do i need special tools for that.

thanks
 
Not likely just the outer seal in this case.-------A pressure test will find the leak !!----------No special tools required to change the seals.----------------Might be best to get a complete seal kit so that you do not miss anything.----Pressure test after you are done with the work just to be sure.
 
I made my own years and years ago.----Uses a 3/8" NC threaded piece , shreader valve , pressure gauge and a bicycle pump to put about 5 PSI pressure on the unit.
 
Not likely just the outer seal in this case.-------A pressure test will find the leak !!----------No special tools required to change the seals.----------------Might be best to get a complete seal kit so that you do not miss anything.----Pressure test after you are done with the work just to be sure.


Thanks for the help

Will pressure test tell you anything about water getting in. I can see if you are testing oil leaking out how it would tell you where the leak is
 
Pressure testing has been a standard practice in outboard repairs for many , many years.------If air can leak out , water can leak in !!!!----I normally let a gearcase sit overnight and check pressure the next day.----If you are impatient then soapy water will help find the leak.---------Common area of leakage is the shift rod o-ring.---On later models they have changed the housing and now uses 2 o-rings there.
 
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can you enplane the tester further a 3/8 NC is not hollow did you drill and tap to put a air fitting on and a tee of some kind for gage. ?
 
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