How do I remove vacuum breaker

The photo here shows my outdoor spigot where I attach my garden hose. I learned that the nut with the circular hole design is called a vacuum breaker. It needs to be replaced because water leaks out the holes when I use the garden hose.

How do I remove and replace this thing? Someone said I would need to partially saw through it first, and then undo the screw? It looks like there is a pin or screw in the photo. Where exactly would I saw through or what would I unscrew or loosen? Do I really have go to the trouble of sawing to get this thing off? Thanks.

 

It should just unscrew off. You'll probably need a wrench on both the spigot and the vacuum breaker. I think some of them also use a set screw so you might want to inspect closely before you start. At 2nd glance, I believe that's a set screw on the left. Might want to spray it with some PB Blaster first.

 

Yep, you really do. The setscrew is snapped off as it is tightened since they are required by code.

A Dremel works nicely but you have to be careful not to damage the spigot threads too much. A few nicks won't hurt, but if you cut through them to the inside of the spigot, it will need to be replaced. You could probably use a stubby hacksaw but the dremel cuts faster and is easy to control.

The ones I've done, I just cut 2 notches (one on each side) the length of the vacuum breaker, then insert a couple of big screwdrivers and twist They normally crack and come right off. Takes about 5 min.

 

I guess I'm not sure where I do the sawing. Do I saw horizontally on both sides of the big hex nut with the holes-in-a-circle pattern?

 

You may be able to gently drill out the setscrew and not have to make cuts. The setscrew is what is keeping the vacuum breaker from unscrewing off of the hose bibb. Vacuum breaker screws onto the hose bibb just like a hose would.

 

CAUTION!!!!: Make sure you use two wrenches when unscrewing the vacuum breaker!!! One to unscrew the breaker and one as a backer wrench to hold hose bibb in place. If not, you may (will) put to much force on the pipe coming out of wall and it may (will) break.
This isn't the best picture, but hopefully you will get the idea:



Put pressure on the wrenches only, push one and hold one, don't put pressure on pipe!!

 

Hey, cool diagram you superimposed on my photo. Very helpful. Thanks for everyone's input. I'll reply also when I get the thing off. Backyard spigot needs to be done too.

 

I was able to remove the vacuum breakers. But the hose bibb threads are a bit worn, cracked, and flattened. I might have caused some damage too. So I need to replace the bibbs anyway.

Are the bibbs easy enough to remove? Just unscrew counterclockwise with a pipe wrench? Thanks

 

Can you tell if the spigot is threaded? or is is soldered on?

 

The threads may be in poor condition and yet the seal to the hose is okay. The threads are not the sealing point, the gasket in the hose coupler is the seal. I suggest checking this out before replacing the faucet.

 

My hose bibbs are sweated on. The threads are damaged enough that the garden hose screws on crooked. I must have damaged it when I was removing old vaccum breakers.

 

I hired friendly neighborhood plumber for this repair and he gave me a good discount. He used adapters to fit threaded hose bibbs instead of sweating them on. He says if I ever need to replace the hose bibbs again, I can screw these on myself and save money. I refuse to use those vacuum breakers again. I'll just make sure my garden hose is secured from any potential vacuum hazard which I am told is unlikely anyway.

 

I've always figured that the only reason that vacuum breakers were mandated by some jurisdictions is because of a super salesman. Too many things have to be just right for your garden hose to siphon dirty water back into the water system. The odds are it will never happen.

 

Oh good grief. The answer here is brute force. Put a couple of pipe wrenches on that situation and crank it off. That set screw is not going to resist that kind of torque, corroded or not.
Don't want to bother with that method? This is why they make Sawzalls. Cut through the brass and break it off as others have suggested.
Or for the finesse answer: Cut the tubing, clean it up, sweat on a new hose bibb and be done with it.

IMHO... Nothing worse in the world than meddling "authorities" who add idiotic requirements like vacuum breakers on garden hose bibbs. Like what, there is going to be a sudden reversal of pressure in the whole system at just the same time you have your garden hose dangling in a tank of cyanide?
In my regular job I am constantly using garden hoses to fill tanks. We avoid back vacuuming by keeping the tank lower than the source and never letting it drop into the liquid. But it never fails: Every vacuum breaker in the world leaks like a seive.