Hey Moses, sounds like there is dirt in the inlet valve. If you can isolate the water is it possible to strip it to see?
Possibly you may choose to replace the whole unit.
Below is the link to the instructions.
http://www.ultimatehandyman.co.uk/ball_valves/fitting_replacing.htm
the drip
December 2010
I can answer this question...
System in Cistern restricts the inflow of water, seems rubber sticks re lev?
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