Have a couple of 7 year old outdoor spigots that have the vacuum breaker that constantly leaks. Trying to figure out how to get these suckers replaced or repaired. Don't see a set screw to drill into just a couple of notches on the side. Anybody have any ideas on how to remove these?

Thanks for any input you have.

Looks like this:

Is the faucet dripping?
Or does it leak out the vacuum breaker when you hook up a hose to it?

I tried to remove one like that & mangled it without budging.
When I went to Menards to get a new hose bib, I saw that all the replacement vacuum breakers had break-away set screws.
I replaced it anyway, but I bet there is a small hole that's filled with the set screw you could drill out.
It was like $15 for a new vacuum breaker & 30 for a whole new faucet. I wanted a valve behind it anyway in case I leave a hose connected & it freezes (ask me how I know to want this....)

When one of mine did that, I took the vacuum thing off, tapped the hole for a pipe plug, and called it good. That was 7 or 8 years ago at least.

It can be screwed onto the pipe or soldered.

Threaded is "flush flange" and soldered has a "stub" in the back extended on the back side of the flange.

Then the pipe may be threaded or soldered further back where the intersection to the supply line is located.

If you have access to the interior wall, cutting the rock and looking at it from the back side may be helpful.

If you can clean up the mortar and get an eyeball behind the flange, and see if it is threaded or soldered, you might be able to remove/replace if it is threaded, but trying to twist may break the line inside the wall.

If it were me, I would be cutting the rock and see what I had before doing anything.

If you are talking about removing just the anti-siphon valve, see if it has a "lock pin" or break off screw, and carefully center punch and drill it out, then remove, and replace the valve.

It only leaks when the hose is connected and the water is turned on. I can't see the set screw just the notch in the above photo. There is another similar notch on the other side as well. Even with the water running and the hose turned on the vacuum breaker leaks, as designed I guess, but there is no back pressure.

Another view: Is the circular area by the white spot the set screw thats been sheared off? I didn't think so but maybe it is.

Vacuum breaker

Looks about right, stainless/nickel set screw on brass.

Vacuum breakers get gummed up from minerals deposits (mainly from relieving pressure then the water drops drying).

You can try to drill out the set screws and replace the vacuum breaker. My faucet that gets the most use (hose hooked to float switch and faucet always on), I ended up replacing the faucet and then I purposefully didn't engage the set screws so I can swap out the vacuum breaker.