I have recently purchased a 50 y.o. home, split-level, 2-1/2 bath. The toilet in the full bath upstairs "locks" when filling. It may fill 3-4 times or only a few seconds when a "hammer" knock is heard in the line and the water shuts off completely. I disconnect the flexible hose at the valve at the floor, bleed tiny amount of water from the valve, reconnect line and water flows again for as little as a few seconds to > 1/2 hour.
I have inquired at several hardware/plumbing outlets and even consulted a retired plumber with no answer.
All other faucets/toilets/outlets seem to be fine at this time - it's only this one toilet in question.
I'll certainly appreciate any help I can get!