Welcome to TFP:wave: From what I can tell you can unscrew your wall fitting and take out the piece that is stuck inside it with a pair of pliers. Look at this link for parts
Polaris 3900 SPORT Swimming Pool Cleaner Parts
Hope this helps:cheers:
I believe it should last quite a few years. I have a Polaris (8years old) and it still looks like brand new however I only use it about 2 times a year. When not in use it is in the original box in the garage.
Do you leave it in the pool all the time?
What is your water chemistry? If you have too...
We have a polarias 360 and it seems to do a great job. Only use it one or twice a year as we too have a screened in pool. I use cut off legs from a panty hose inside the fine screen bag and it picks up all the fine sand. Hope this helps:cheers: