How To Change a Sta-Rite Max-E-Pro Pump Impeller

This guide provides a step-by-step procedure for replacing the impeller in a pump that is clamped together. A pump has two major sections: the wet end which holds the water and the motor which dives the pump's impeller to move the water. Generally these two sections are either bolted together (like most Hayward pumps) or clamped together (like most Sta-Rite pumps). 

1. INTRO TO HOW AN IMPELLER WORKS - For a quick introduction, this picture shows the operation of the impeller. Water enters the center of the impeller. As the impeller is spun by the motor, a series of blades, like a fan, pushes the water to the outside edges of the impeller where it exits through slots to be collected by the diffuser. 

2. TURN POWER OFF - The first step in preparing to remove your pump's impeller is to turn off all power to the motor. For maximum safety turn off the power at the circuit breaker to the motor - usually located next to the timer box.

3. RELIEVE PRESSURE - Next you will have to relieve the pressure that builds up in the pump during operation. To relieve pressure turn the relief valve on top of the filter counter clockwise. Water will spray out initially as you see the pressure on the pressure gauge go to 0 psi.

4. UNSCREW CLAMP - Unscrew the knob on the pump clamp in a counter-clockwise direction to separate the ends of the clamp.

5. REMOVE CLAMP - Slide the clamp off of the collars that join the pump sections together.

6. SEPARATE SECTIONS - Rotate the motor section of the pump down and out of the pump wet end.

7. NOTE POSITIONING - As you are taking the motor section out, note how it is positioned relative to the wet end. When you put these sections back together, the tab in the motor section will be inserted into the slot on the wet end.

8. INSPECT DIFFUSER O-RING - Inspect the O-ring on the Diffuser to make sure it is tight and has no breaks of cracks. Replace is required.

9. INSPECT CLAMP O-RING - Inspect the O-ring in the groove of the wet end. Replace if required.

10. UNSCREW DIFFUSER - Remove the 5 screws that secure the Diffuser to the motor Seal Plate - turn counter-clockwise.

11. NOTE POSITIONING - As you are removing the Diffuser, note how it is positioned relative to the wet end. When you put the Diffuser back onto the Seal Plate, the slot on the Diffuser will engage with the tab on the Seal Plate.

12. LIFT OFF DIFFUSER - With the screws removed, lift the Diffuser off of the top of the Seal Plate.

13. UNSCREW ELECTRICAL COVER - Go to the back of the motor and remove the two screws that secure the Electrical Cover.

14. REMOVE COVER - Remove the Electrical Cover to expose the electrical circuits of the motor.

15. SECURE MOTOR SHAFT - Slip a flat open ended wrench under the wiring until it engages with the flatted sides of the motor shaft underneath the Governor.

16. REMOVE IMPELLER SCREW - Go to the other end of the motor and remove the Impeller Screw. NOTE: THIS IS A LEFT HANDED THREADED SCREW. Turn it CLOCKWISE to loosen it. If you turn it counter-clockwise like most screws, you will break the screw.

17. CHECK IMPELLER SCREW O-RING - Check the small O-ring at the base of the Impeller Screw. Replace if damaged.

18. TWIST OFF IMPELLER - With the flat wrench in place to keep the motor shaft from rotating, unscrew the Impeller from the motor shaft by hand. Turn the Impeller counter-clockwise. If the Impeller is stuck on the shaft, use a strap wrench to free it. Do not use an adjustable wrench.

19. VIEW SHAFT SEAL SECTIONS - This picture shows you the location of the two pieces of the shaft seal. One is on the Impeller Shaft and one is in the Seal Plate.

20. REMOVE SHAFT SEAL FROM IMPELLER - Twist the Impeller Shaft Seal half off the shaft of the Impeller. This should come off without much effort. Note that the spring end of the seal was placed next to the Impeller.

21. UNBOLT SEAL PLATE - To get to the other half of the Shaft Seal, you will have to remove the Seal Plate from the Motor. Unbolt the four bolts that secure the Seal Plate to the Motor.

22. SEPARATE SEAL PLATE FROM MOTOR - With the bolts removed, lift the Motor off of the Seal Plate. Note the position of the Seal Plate to the Motor. The top of the Motor will line up with the flange part at the top of the Seal Plate.

23. PUNCH OUT SEAL - With the other side of the Seal Plate open, you can now use a small screw driver to punch out the other half of the Shaft Seal. The Seal should come out easily.

24. VIEW SHAFT SEAL SECTIONS - This is a picture of the two halves of the Seal once they are removed. When you put the new ones in, the white ceramic end of the one should make contact with the black ceramic end of the other.

25. SLIDE SHAFT SEAL ON IMPELLER - Twist the black ceramic Seal section onto the Impeller shaft. Make sure the spring end is towards the Impeller.

26. INSERT SHAFT SEAL INTO SEAL PLATE - Push the other half of the Seal into the Seal Plate. Make sure it is pushed all the way into the well. You might use the handle end of a screwdriver to help push it all the way in.

27. WIPE SEAL SURFACES - Wipe the ceramic surfaces (black and white) with a clean cloth to remove any dirt or oil from your fingertips.

28. REATTACH SEAL PLATE - Bolt the motor back onto the Seal Plate. Remember to line up the top of the motor with the flange of the Seal Plate.

29. TWIST ON IMPELLER - Twist the Impeller back onto the Motor Shaft with a clockwise motion.

30. REPLACE ELECTRICAL COVER - Replace the Electrical Cover on the other end of the motor and secure it with the two screws.

31. SCREW ON DIFFUSER - Secure the Diffuser onto the Seal Plate with the five screws. Line up the slots on the Diffuser with the black tab on the Seal Plate as shown.

32. INSERT MOTOR INTO WET END - Place the motor onto the supporting bracket and push it into the Wet End. Make sure the tab on the Seal Plate lines up with the slot in the Wet End.

33. SECURE CLAMP - Make sure the Wet End and Motor are pushed together. Then slide the Clamp over the joint between the two and secure it by tightening the Clamp Knob. Turn clockwise. To make sure the Clamp seats properly, tap around it occasionally with a rubber mallet as you are tightening the knob.

34. REMOVE STRAINER COVER - Remove the strainer cover from the top of the pump by twisting it in a counter-clockwise direction.

35. PRIME PUMP - Prime the pump with water from a garden hose. Note: the pump has been removed from its piping. Assume that the input and discharge ports have been reconnected to the system piping.

36. REPLACE COVER - Check the Strainer Cover O-ring and replace it if necessary. Lubricate the O-ring and replace the strainer cover from the top of the pump by twisting it in a clockwise direction.

37. TURN ON POWER - Reset circuit breakers and start pump.

38. CLOSE RELIEF VALVE - Close the relief valve on top of the filter, after the air is purged and water starts to spray out of the valve.

39. CHECK FOR LEAKS - Check for leaks around all the O-rings and gaskets you changed in this procedure to make sure the connections are tight enough.

If you have any other questions about pool and spa products please do let us know - we are here to help! 

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