Dunbar Water Pump
by
Bruce Wm. Anderson
Picture 1
Left - Dunbar Water Pump
Right - Dunbar Eccentric Drive
Left - Dunbar Water Pump
Right - Dunbar Eccentric Drive
Picture 2
Dunbar Water Pump Disassembled
Dunbar Water Pump Disassembled
Picture 3
During the normal workday the boiler water is replenished by using the Water Pump (Picture 1 & Picture 2 - disassembled Water Pump) to pump water out of the water storage tank and back into the boiler. The Water Pump is a piston pump that makes use of two ball valves (Picture 3) to direct the water as the pump cycles. If the water pump fails to pump water it is usually due to contamination of the ball valves with oil or debris. In this case the caps must be removed and the balls removed with a ball spoon (Picture will be added later). After cleaning the balls and the valve seat they should be reassembled. Occasionally, the ball will need to be tapped on the seat to reestablish a seal. We have noticed in our wagon that when the pump is not working properly, water in the Water Sight Glass fluctuates up and down greatly. This is usually resolved by cleaning the ball valves. A second problem is an air leak at the water pump's packing. This is resolved by tightening the packing nut and/or replacing the packing. The piston is driven by an eccentric (Picture 1) which is powered by the steam engine drive that also has an operator operated clutch (Picture will be added later). The soldered copper water storage tank is filled with water at the beginning of the day. Then the boiler is replenished by the pump with the condensed steam and water from the water storage tank throughout the workday. This gives enough water capacity for an entire day. It is best to use distilled water if possible to prevent a buildup of minerals within the boiler. In a carbon copy letter from the Dunbar factory a solution is given to be used in the water storage tank and boiler to remove excess steam cylinder oil and mineral deposits.