Is it normal for a Hypro roller pump to growl? Like a power steering pump thats low on fluid when you turn the wheel. That's what mine sounds like. Its a brand new pump, i cant see any leaks on the suction side and i used Teflon tape on everything and tightened it up. Still cant get the growling to go away unless i idle the engine, then it is quiet. I think its getting air somehow, but I dont see how. The only problem I see is that i put a strainer inline right before the pump and it is plastic - where the rest of the system is galvanized steel. There IS a pressure relief valve, the pump is not being over sped (rated for 2600rpm speed, and i'm running it at most 2400 according to the tachometer) and I am pumping fresh clean water from a tank, through a 5/8" hose only 7 feet long. Anyone got any idea whats wrong? Shouldn't this pump be silent? Also this is a 4101 pump. Silvercast with Viton? seals. Will it stand up to bleach water as long as I flush the system each time I get done? I built this specifically to spray bleach (i use bleach as a cleaner to remove mold and mildew from houses as I do power washing as well as lawn mowing).