I have an outdoor faucet connected to a garden hose and pistol type spray nozzle. The connection is leak free until I turn the water off and pull the trigger on the spray nozzle to get some of the rest of the water out and relieve the pressure on the hose. When I do this, water comes gushing out of the connection from the faucet to the hose.
Does anybody have any idea what this is and what I can do about it?
Some other information:
-I thought it could be the the washer, but I just bought a new hose and made sure the rubber washer was in good share and in place
-I've tried both wrench tightening the hose as well as the other end of the spectrum with light hand tightening
-The faucet itself is only about 3 years old, and as I mentioned, doesn't leak while the water is on
Thank you!
UPDATE:
Adding photos of the faucet: one with the hose attached and one without
Best Answer
Actually, it sounds more like a siphon or vacuum breaker working fine. It's not leaking with pressure on. When you turn off the sillcock and release pressure on the hose, it moves the water in the hose away from the sillcock, creating a vacuum at the faucet, which causes the siphon breaker valve to open. Then the water rebounds a bit and some comes out. They have only failed when they leak under pressure, or do not open at all. The brass cap thing on top of this sillcock is the built-in vacuum-breaker. The type described in Steven's answer seems more likely given where you say water is coming out. In either case, I don't see any sign of failure from your description of the behavior.