Hello Mates. Every time I clean the A/C raw water pump filter, the pump cavitates. I tried filling the filter housing with water before re-adding, but it didn't help. I have to remove the output hose and turn on pump to let water flow to stop cavitating. A previous post in a different forum showed a valve and hose fittings to add to the output of the pump but I can't find the post now. Opening the valve momentarily would eliminate removing the hose from the pump. Other boats in my marina have this problem also. I'm thinking someone on this forum has added a valve and can inform me what valve and fittings to buy. I believe the ID of the hose is 1/2 inch.