Turn off the pool filter. Whether you're going to clean the filter or your Hayward pump you must make sure that the filter/pump are not running. More than just flipping the switch to off, make sure to unplug it from the electric source. Most pool filters/pumps are on timers and you don't want to turn it off only to have the timer turn it back on.
Set of the hose valve positions to "Off." If any of the hoses that connect your pool to the filter have on/off valves, turn them off to prevent water from flowing to or from the pool. If your pool doesn't have on/off valves, disconnect the hoses and place the open end in the pool to prevent water from escaping.
Open the pump basket cover. Once you open the font basket cover the remaining water trapped within the pool filter will flow back through the pump and exit through the open pump basket. However, since you disconnected or shut the water valve off you can rest assured that water from your pool is not continuously draining through the pump basket. Remove the pump basket and empty the debris.
Clear the connection between the impeller and the pump basket. To do this you'll have to stick your fingers into the tube area just beyond the pump basket. Sometimes leaves and other debris are caught in this area that can affect the Hayward pump's operation.
Clean the impeller. The impeller is the Hayward mechanism that spins around to create the vacuum that draws the water from the pool to push it through the pool cleaning filter. If the impeller becomes clogged or defective in any way your pool filter will not operate properly. Reach in and pull out any dirt debris or leaves that may be caught or stuck in the impeller.
Reconnect the filter. Now that your Hayward pool pump is clean it's time to reconnect all of the hoses, plug the Hayward pump into the electric source, open the air valve and turn on the pump. Once all the trapped air has escaped, close the air valve and your pool pump and filter should run smoothly.