A lot of our antique cars have, or had a grease fitting or a grease cup on the water pump. Without the proper grease, the water pump bearings will quickly fail. In some cars, particularly Model A Fords, the grease may pass through the water pump in to the cooling system. Ford specified a special water soluble grease. Using a conventional grease can cause a blockage in the radiator. Chrysler specified a special grease for use on their water pumps too.
So, what makes water pump grease different than conventional chassis grease? Depending on the grease, it is either a grease that won’t be washed away by water, or a water soluble grease that will wash away and dissolve in water preventing a blockage in the cooling system.
Many replacement or rebuilt water pumps have modern, sealed bearings. Most of these pumps use the original casting and either have a grease fitting, or grease cup, or a spot for the grease fitting to be fitted. Many concourse restoration pumps actually have dummy grease fittings or grease cups to “look the part” of the factory pump.
The question is, what grease to use? If you need a water soluble grease, such as for a Model A, most Model A parts- houses stock the water soluble water pump grease.
There are several options for non water soluble grease. Most auto parts stores stopped stocking water pump grease decades ago. The most popular modern replacement is marine grease, or the wheel bearing grease for boat trailers. Many people use Lubriplate 115 for water pump grease. Marine shops carry outboard motor grease. Another option is your local fire department. The pumps in fire trucks requires a special, water pump grease. This grease is sitting right on the shelf at the fire house. If you are lucky, they may give you a few pumps from their grease gun, or several ounces from the tub they are using.
Please email all inquiries to: Dave
or snail mail
32 Turkey Hill Road
Richmond VT 05477