The seal is a very oddball design, a spring-loaded "mechanical seal" consisting of a ceramic disc with a carbon ring spinning against it, held together by a stiff spring.
Its only oddball in the automotive field. It is very common in centrifugal pumps. Mechanical seals are far superior to any type of packing sealing a rotating shaft to a stationary housing. The seals rotating face and stationary face don’t actually touch but instead ride on a thin film of the fluid that they are sealing, in this case antifreeze, so they tend to last a very long time. Most mechanical seal failures are due to worn or failed bearings. I’ve installed many and HRL is right about the carbon rotating face (ring) as being fragile. You also can’t touch it with your bare hands, as the oils in your fingers can also effect it life.
That being said, if I could obtain the rebuild kit, I wouldn’t hesitate in rebuilding the water pump.
