The ballcock squels during refill of tank.

I replace the flush valve on both of my toilets due to water leaking from tank However since I replace the flush valve both toilets make a squealing moaning sound when the water is refilling before the replacing there was no noise.I have turn the water inlet valet all the way open still same noise...

Hi, Just the last couple of weeks our en-suite toilet cistern has started to squeal after flushing the toilet in the bathroom! This happens even if we have not used the en-suite for hours so its not when it is filling up. Does anyone have any ideas?? Thanks