First off I apologize if this has been addressed. But, I have looked through the forms with no resolution to my problem and noticed that although there are simaler pump problems, it is always when implementing a new pump. My problem is as follows: I've been brewing for almost a year now with a March 809 HS. I do 15 gal batches and the pump has pushed through 25 batches so far. On the last couple of batches, though, it is cavitationing when pumping the hotter liquids coming from the HLT and BK for some reason. At least I think that is what is happening. It pumps a little liquid and then bogs down for a second, then revs higher and then doesn't push liquid any longer. Then I have to turn it off, in which it makes a squeal/grinding noise as it turns off and I must re prime to start again. I have read several forms of this happening in which the individuals increase the inlet flow or they restrict the output flow. My system goes into a pony keg lauter grant and I have a ball valve on the outlet that I restrict the flow with no resolution. All I can come up with is that my pump on the outs as I have gone through many brews without this problem. Does anyone have knowledge of their pump doing this after it gets old and if so is there just some replacement parts I can get? Thanks for the Help