Water Hammer

[JBR160]

Trying to figure out my water hammer issue that started this season. I replaced the water pump last year with a Shurflo 4008-101-E65 and everything ran great all last season.

This season the water hammer started on our first trip. I have checked for leaks thru out the camper and could not find anything. I had a small drip leak at the water tank fill. Tightened the hose clamps and that took care of that problem. It does not hammer when I hook up to city water at all, only when on the pump. Also, the pump does not run constantly and this only happens when I turn and of the faucets or flush the toilet. Tightened all the pump fittings and even pulled the pump to check the diaphragm and could not see any splits or cracks.

Thought I would check with the experts before I either go and purchase a new pump or drop it off at the RV mechanic. Really do not want to pay the $150 per hour to tell me something I could have done myself!

Any help would be appreciated!
Thanks