I also rebuilt my Challenger pump, got the kit from Hydro-e-lectric who also sell cylinders, hoses etc. I had one question and they answered it quickly and efficiently. I agree it's pretty straightforward to do. I plumbed mine back in and it all works as it should. My only issue is a small weep which I have yet to diagnose. I'm guessing it's the reservoir O-ring, maybe it's not quite tight enough (or too tight...?) which I was planning to ask them about....