Sometime recently my toilet reservoir tank would not stop filling. It fill the tank to its normal capacity until the float is raised. Once that is done it continues to fill really slow. You probably wouldn't notice it unless it was really quiet and then you could hear the flow.
If left alone it would eventually reach the overflow. So it is no a case of the float level being above the overflow. If I was to pull the float up as high as it comfortably goes the flow persists.
The toilet is working normally. During this slow flow the water is not filling in the bowl so this issue should be limited to the resevoir. There are no leaks outside of the tank that I can find so I think the issue is with the ballcock?