My Polaris PB4 booster pump for my Polaris 280 may be bad. It randomly makes a loud buzzing noise and doesn't pump water. I called Polaris and right away, she said it sounded like the motor is bad. I'm going to remove the cover and see if I can move the impeller. The motor has a separate part number, so I'm thinking about replacing it myself. Is it difficult? I've seen the exploded diagram and the only part which I'm not sure about is removing and installing the cup and seal. I've seen a seal replacement procedure online and it doesn't seem too difficult.