I am fixing one of 26 sloan valves in the building. It randomly started running so I closed the shutoff as best as possible and put in a new vaccum breaker, diaphram and shut off but now it hammers pretty bad and it did not before. I've fixed other valves where this did not happen. I am by no means a commercial plumber, doing maintenance for the building and do what I can to save money. Any advice or help would be greatly appreciated!