Early Water Pump Lubrication & Maintenance

By Stephen Kassis

Early Chevrolet water pumps from 1916 thru 1937 have bushings that require constant maintenance. This style of water pump needs lubrication: oil on the pulley bushing every 50-100 miles & water pump grease from the grease cup around every 100 miles. In addition, whenever leaking is noticed, the packing nut should be checked and tightened. If the packing nut is turned all the way in, it will be necessary to add a ring of packing and readjust the nut. Failure to properly maintain this style of water pump can cause failure of the bushings, and leaking that cannot be stopped. At that point the only option is to rebuild or replace the water pump.

Each time these early cars & trucks are driven, it is vital that the water pump is lubricated. In the front of the water pump snout, there is an oil galley. Sometimes this has a metal, spring-loaded cap on it and sometimes it is just an open valley. Put a few drops of oil on this bushing each time the vehicle is run. A fan belt that is too tight can damage the front bushing and cause it to fail. It is important that the fan belt is left as loose as possible while still making the fan move. Over-tightening of the fan belt can cause premature failure of the front bushing. KEEP THE BELT LOOSE and the water pump bushings will last longer.

The water pump packing nut squeezes water pump packing around the shaft to prevent leakage. It will also prevent air being sucked into the impeller of the water pump. Air around the water pump impeller will cause cavitation and prevent circulation of water, a common causing of overheating. If you run anti-freeze in the radiator, air at the impeller will also cause the anti-freeze to foam and push out the radiator cap.

If leaking is noted, turn in the brass packing nut with a 1″ open end wrench until the leaking stops. If the packing nut is turned in all the way, back out the nut completely and add a single split ring water pump packing into the cavity. Start the packing nut back into the housing being cautious that it is not cross threaded. Tighten the nut until the leaking stops. Caution: over-tightening this nut can cause the shaft to seize.

Finally, the grease cup should be turned in around every 100 miles. A proper water pump grease should be used in the grease cup.

Several years ago, The Filling Station developed a sealed bearing water pump for 1929-1934 Chevrolet cars & trucks (except for 1933-1934 Standard). This sealed bearing water pump eliminates all lubrication maintenance requirements. These are all new units that come complete with a pulley. The sealed bearings eliminate the need for lubrication and the pumps look identical to original water pumps. For show purposes, you can install your original grease cup onto the new pump but it will just be for looks as no lubrication is required. As with the original water pumps, belt tension should be as loose as possible while still turning the fan.

An additional benefit of the newly designed sealed bearing water pump is that the engine compartment and firewall be much cleaner. No oil or grease will be blown up onto the engine or firewall from the water pump. It is a truly maintenance free water pump!