BX2660 - Bypass valve whine when hot

[EE_Bota]

Yep squealing again and its driving me crazy. I just tried re-routing the bypass line (hose) slightly to see if that changes anything but did not have a chance to test it and it will be two weeks before I am back onshore.

I know that when this happens if I touch the bypass hose it sure feels like its coming from there. In talking to some guys here at work in there opinion it sounds like the classic hot fluid passing through a restriction sound. I still think its one of the QC on the back. I am going to change all three when I get home to see if that solves the issue.

I had a set of QC's that had a spring strength difference such that when you press them together, and the two small nubs press against each other to open the poppets, one would fully open, and the other would remain almost fully closed.
I had to replace them all with a very nice name brand.

I have seen QC poppets that have a limit to how far they CAN open, making it so that spring strengths side to side are irrelevant, but I have not seen that in years now. Apparently most of them are relying on the springs to be of relatively equal strength, which is a fool's game if they considered what is at risk.