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  1. #1
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    Lower unit pressure tester

    I can't take credit for this, saw it on YouTube but came up with a little water in my lower unit and wanted to test my seals. I kind of figured that it was the drain plug gasket but this helped me confirm that. Brake bleeding pump with a gauge and a LU lube fill pump (just for the fitting). Cost like $30.

    pump.jpgfitting.jpg

  2. BOOMER SOONER OkieBud's Avatar
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    #2

  3. Member
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    Oct 2011
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    #3
    I was trying to come up with a tool for doing just this. Thanks!

  4. Member
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    #4
    I did the same thing with a foot operated bicycle tire inflator with a gauge on it. Works great and cost about $20.

  5. Member
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    #5
    I'm assuming you check this with the lower unit empty of oil? And how do you determine where the leak is, if any?

  6. Member
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    Mar 2015
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    #6
    Quote Originally Posted by MarKimBassTeam2021 View Post
    I'm assuming you check this with the lower unit empty of oil? And how do you determine where the leak is, if any?
    Yes, lower unit empty and removed from motor. If it holds pressure, there's no leak. If not, once it has pressure, spray soapy water around all of the seals. Prop shaft, drive shaft and shift shaft.

  7. Member
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    Jan 2021
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    Sweetwater, TN
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    #7
    Ok thanks. But please explain to me why the lower unit has to be removed?

  8. Member
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    #8
    Quote Originally Posted by MarKimBassTeam2021 View Post
    Ok thanks. But please explain to me why the lower unit has to be removed?
    The drive shaft and shift shaft seals are on top of it. You can't see them without removing it.

  9. Member
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    Sweetwater, TN
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    #9
    Oh, Ok. Thanks. Now I'll have to get the procedure on dropping the lower unit on my 1986 Johnson GT 150hp.

  10. Member
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    Aug 2017
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    Hillsboro, NH
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    #10
    Quote Originally Posted by MarKimBassTeam2021 View Post
    Oh, Ok. Thanks. Now I'll have to get the procedure on dropping the lower unit on my 1986 Johnson GT 150hp.
    It's not hard, except getting the bolt back in the top of the shift rod (tape it into the socket).

  11. Member
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    Sweetwater, TN
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    #11
    Thanks Guys, bassboatcentral Rocks!!

  12. Member
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    #12
    I still think this is an awesome idea.

  13. Member
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    #13
    Quote Originally Posted by mrdeath View Post
    I did the same thing with a foot operated bicycle tire inflator with a gauge on it. Works great and cost about $20.
    That's the same way I made one.