So for the last 15 years of working on 1fz's I've yet to come across one that needed a water pump. The only time I've replaced one was when the customer requested it or there was so much rust and crap in the oil cooler I just did it just to make sure it wouldn't fail but that is maybe 2 or 3 out of 300 or more 1fz's that we have had in the shop for head gaskets or cooling services. I just don't see them fail. Now I know there are probably dozens of examples here on MUD of them failing but it's super rare. My question is why? I've seen plenty of 40, 60, 70, 100, 120 and 200 series with mostly failed seals where coolant is coming out the weep hole. What makes the 1fz water pump so much better?