There are a handful of well documented accounts on the web of repairs to a leaking liquid-cooled G5 tower, involving not only replacement of O-rings (the main point of failure, apparently), tubing, fluid and in at least one of the cases pumps, but also the cleaning up of encrusted processors on which fluid has leaked and then evaporated, leaving behind whatever it is that was suspended in the fluid. I don't think it is ordinary ethyl glycol coolant that is used, but whatever. The residual substance appears almost salt-like. Among the tell-tale signs of the problems associated with the leak are random shutdowns and such, though in severe cases the machine will not start at all.
I would have thought, looking at this as a theoretical project somewhere down the line, that a machine which is leaking but which runs, however problematically, would be a likely candidate for successful repair. Only at the right price, of course (i.e., scrap), but it could be a cheap way to get a functioning G5 if it worked, and a bit of fun along the way. Methinks, mind you, that the corrosion one sees on the PS in photos of leaking units means that you wouldn't want to obtain one in which the crud has been left lying around for too long.
Anyway, as I said earlier, it is perfectly possible to restore a failed liquid cooled unit. The skill required is relatively basic mechanical/ DIY competence; if you can change your brakes, you can fix a G5. The resources needed are just a few tools and a handful of spare parts, all of them easily available and few of them expensive (apart from the pumps, perhaps, but they should still be good in most units).
I would have thought, looking at this as a theoretical project somewhere down the line, that a machine which is leaking but which runs, however problematically, would be a likely candidate for successful repair. Only at the right price, of course (i.e., scrap), but it could be a cheap way to get a functioning G5 if it worked, and a bit of fun along the way. Methinks, mind you, that the corrosion one sees on the PS in photos of leaking units means that you wouldn't want to obtain one in which the crud has been left lying around for too long.
Anyway, as I said earlier, it is perfectly possible to restore a failed liquid cooled unit. The skill required is relatively basic mechanical/ DIY competence; if you can change your brakes, you can fix a G5. The resources needed are just a few tools and a handful of spare parts, all of them easily available and few of them expensive (apart from the pumps, perhaps, but they should still be good in most units).