And the other nuts are ok?
Sure looks like it’s from a leak. Maybe the close in is deceiving but it looks like there corrosion around the pump base as if it hasn’t been serviced or inspected in a LONG time. When was it last off or the pump checked?
Ken, ya really gotta start taking notes!!!
Vic wrote back on page 1:
I replaced the pump assembly 7 or 8 years ago.
Say he does the standard 100 hours per year. That's 700 to 800 hours. My first go-round showed 1300 hours before my seals required replacement. I may have noted on page 1 that I got 800 hours out of the last ones before I pulled the pump and replaced them in November last year on what I call my repair #1. The seals weren't the problem, the disappeared metal holding the stud in was the problem but I was too dumb to notice it.
I agree that Vic's picture looks just like what one would expect from a leaking water seal. It appears that this is the lowest stud and nut on the starboard side, although it is hard to tell from the super close-up picture. Perhaps Vic could answer our questions about which nut it was specifically, to see if we're close.
Vic, your OP said you think the stud is a goner. From that picture, I think you may be in GREAT luck and it's just a rusted nut, and the stud may be just fine.
I am reminded of the advice on the Critical Upgrades topic: Watch your engine while it's running.
That rust didn't happen overnight.
My oil leak, by comparison, certainly did.
