Need help diagnosing a pump issue

[soccercta100]

I'm a relatively new pool owner (2 summers using the TFP method--big fan!) and I need some help diagnosing an issue I'm having with my pool pump. I just turned it on backwash for the first time this spring and everything seems to run fine until right before the pump basket is just about primed. Once it reaches that point, the pump motor slowly starts to rev down, I hear a clicking noise from the motor, it briefly revs back up and then back down, I hear the clicking noise again, and it then continually repeats this cycle (there's about a 3 second interval between each clicking noise).

I've already detached the pump motor and taken it to Leslie's to see if the capacitor was bad or something like that, but when the service guy hooked it up and ran it, it ran perfectly fine. I then did the same test at my house (ran it detached from the housing), and it ran fine then, as well. Does anyone have any ideas as to what could be causing this issue? Thanks in advance.

 

[mas985]

It could be the centrifugal switch. That is about the only thing that would click on the back of a motor. Perhaps one of the springs popped off the governor.

 

[CJadamec]

Again I agree with Mas the click you are hearing is the spring loaded capicitor cut out flywheel. Once the motor is up to full speed the flywheel takes the capacitor out of the circuit. The capacitor is there to lower the load speed amp draw of the motor. It sounds like the motor is slowing down under load the capacitor is kicking back in which speeds the motor back up. Testing a motor unloaded doesn't give you an accurate picture of motor health.