These Rubber Impeller pumps are made of high quality bronze of maximum corrosion resistance. All shafts consist of stainless steel grade 303. Top of the line models have ball bearings and mechanical seals while others have bronze or carbon bearings and lip type seals. Impellers are made of Neoprene Rubber. Nitrile impellers are available as an option. Flexible blades on the periphery of the impeller provide the pumping action. While the impeller rotates the liquid between the blades is continuously squeezed out into the discharge port by a machined in cam located inside the pump chamber.
To maintain the pump longer, the impeller must be replaced if it is worn out or has been damaged by debris or by running the pump dry. Symptoms of a defective impeller are low pumping pressure and low flow. To replace the impeller remove screws and cover. Pull out the impeller with needle nose pliers or two screwdrivers. Be careful not to dent the pumping chamber with these tools. When inserting new impeller, line up the flat in impeller with the flat in the shaft. Use oil on shaft and avoid forcing the impeller onto the shaft. The impeller should also be removed for storage periods to prevent the blades from taking a permanent set. DO NOT RUN DRY - Rubber impellers generate high rubbing friction unless lubricated by the liquid being pumped. Lack of liquid will cause impeller to burn up.