Coolant Leaking At Aos?

[SoCal Mike]

I'm working on a friend's 02 996 Cab tip that has a small leak coming from below the AOS. I pulled the alternator and was surprised to see coolant coming from the seams of the AOS. I can't imagine coolant running through the AOS so I imagine it is dripping down on top of the AOS. I can't really see any of the hoses running above the aos, anyone familiar with a trouble spot here? I did some searching and didn't find anything related....sure wish it was the expansion tank! Thanks, Mike

[logray]

Coolant does in fact run through the AOS. The AOS are known to last 30-70k, although ymmv - a widely discussed weak point of the 996 - they are inexpensive but in a hard to reach spot.

They are a pain to replace. Having done it both ways, I recommend doing the replacement by removing the transmission rather than going through the top and ripping out the manifolds/etc. Going through the top much more opportunity to install a hose incorrecty or not get a good seating. It could also be a bad hose or clamp.