I'm guessing that the Prestone Water Pump Treatment might have chemicals in it to soften, swell and lubricate the seal in the water pump. Maybe to help a water pump that was weeping coolant? But that's just a guess.
On the Model T, we were just having a conversation at work where the discussion led to the fact that the Model T didn't have a fuel pump. It relied on gravity to feed gasoline to the carburetor, simple and effective.
I looked up the cooling system and found this on Wikipedia:
"The T engine's cooling system reflected the T's simplicity design theme. The first few hundred Model Ts had a water pump, but it was eliminated early in production. Instead, Ford opted for a cheaper and more reliable thermosyphon system. Thermosyphon was a common engine-cooling method of the era. Hot water, being less dense, would rise to the top of the engine and up into the top of the radiator, descending to the bottom as it cooled, and back into the engine. (This was the direction of water flow in most cars which did have water pumps, until the introduction of crossflow radiator designs.) The thermosiphon system was susceptible to overheating if worked heavily, but served well for most Model T usage.
Many types of water pumps were available as aftermarket accessories."
So it started it's production with a water pump but then switched to thermosiphon for virtually the entire run. I never noticed it, but the fan belt on a Model T engine is just that, a fan belt. Look at the picture from Wikipedia:
I'll have to look at cooling system design more carefully as we go to the old car shows this spring.
Sorry for getting off topic, I just found this all rather interesting.
