Outdrive flunked pressure test

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
1979 228 Mercruiser. Alpha 1 lower unit / MC1 upper.


I replaced the water pump on my outdrive and re-assembled and did a pressure test. It leaks down to about 1 lb. over an hours time. I have done the soapy water test on the drain and vent plugs but not sure how to proceed. I did install the quad seal with perfect seal. How do you get at the other seal areas? Do you flip the drive so the yoke is pointing up and then put soapy water in there? ditto with propellor shaft seal?

Should I split the upper and lower at this point?

help appreciated.
 

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
Re: Outdrive flunked pressure test

Someone must have the how to for this leak issue?

help appreciated!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Outdrive flunked pressure test

Hi there,

That sounds much like the shift shaft seal. What I would do is to split the boxes again, blank off the feed hole (the one you put the quad seal in) and retest the lower box. You'll probably find the shift shaft seal leaking. There is a special tool for removing the seal bushing. I normally just buy a complete new bushing with the seal already in it (it's not that expensive). Just take careful note of all the parts you pull off the top of the shaft, and don't pull the shaft out with the bushing, or you'll be stripping down the box to get it back in the shift yoke. Have a manual?

Cheers,

Chris..........
 

84EdH

Chief Petty Officer
Joined
Apr 30, 2011
Messages
575
Re: Outdrive flunked pressure test

thanks for the feedback Chris. I have read that the shift shaft seal is often a culprit. It also sounds like an easier job than the prop shaft seal! I do have a manual.
 
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