Things You'll Need
Pool and spa lubricant
Socket or box wrench
A swimming pool pump is made up of two main parts: the motor and what is called a wet end. The motor provides the power that helps move the components in the wet end of the pump. The wet end is made up of a trap and an impeller; these parts are responsible for moving the pool water. When the water is not flowing properly and the water pressure is low, it generally means that the system has an air leak, a dirty pump basket or a clogged impeller. To raise the pressure (measured in pounds per square inch, or PSI) back up to a normal level, you must address these issues.
Check the pump basket for dirt and debris by removing the two hand-screws from the basket lid, located on the pump assembly.
Remove the lid and the basket screen by lifting them up.
Clean leaves and other debris out the basket assembly using your hands, or by spraying it with a garden hose.
Inspect the gasket around the top of the basket assembly to check for air leaks. Make sure the gasket holes face up and not down or sideways.
Clean the gasket by removing any dirt and debris with your fingers. Lubricate the gasket by rubbing it with pool and spa lubricant.
Set the basket screen back into the basket and screw the basket lid on tightly.
Shut off the power to the pump and remove the hex bolts that hold the motor to the basket assembly, using a socket or box wrench.
Remove the motor, stand it on its end and pull the diffuser from the end of the motor shaft. Check the rubber gasket around the narrow outside edge of the diffuser to see whether it is damaged or missing; if so, replace the gasket.
Turn the spiral veins inside the impeller and check for clogs. Remove any visible clogs with a needle-nose pliers by grasping the debris and pulling it from the impeller.
Reassemble the pump by replacing the diffuser and the hex bolts; tighten them snugly.
Fill the pump pot with clean water and restart the pump; the pressure should now rise to a normal PSI level.
Disconnect all power from the pool pump before working on it.