An improved two-piece plastic impeller has replaced the steel impeller on some earlier models. When changing from the steel to the plastic impeller, discard the washer that sits between the spring top and the impeller bottom (Note: not all steel impellers are equipped with this washer). Use of the washer is not required with plastic impellers.

It should be possible to easily lift the seal spring from the shaft. This spring is important to the operation of the seal for it maintains the contact between the sealing faces.