Leaky outdoor spigot

Hi -

I have a relatively new (2 years) outdoor faucet similar to this kind:
http://www.rd.com/content/openContent.do?contentId=18060

It is leaking badly from the vacuum breaker so I purchased a new vacuum breaker yesterday. However, when I installed it I still have the same problem.

Now, I am thinking I installed it incorrectly, although there doesn't seem to be anything more involved other than just screwing it in tightly. Am I missing something??

Thanks

The picture you have attached has a built-in vacuum breaker, but your comment says you "just screwing it in tightly".
If it's a standard non-freeze hydrant with a screw on vacuum breaker. the vacuum breaker would not leak as it is just a check valve to stop water going back into the wall hydrant from the garden hose.
I would think it is not seating properly. The problem with a wall-hydrant is you cannot replace the cartridge like you would normally do in a faucet as the seat is at the bottom. You would need to replace the whole unit.

The vacume breaker is not a check valve.

As far as the new vacume breaker leaking, you may be installing it wrong / sometimes parts will fall out when you go to install it, or there may be a problem with the bib its self.

So explain how a vacuum breaker and a check valve works.
What parts may fall off from a screw on vacuum breaker?

Hose BIBB vacumm Breaker

MECHANISM OF OPERATION
A hose connector vacuum breaker prevents backflow to the water supply by venting water to atmosphere (onto the ground) when backflow conditions exist. The mechanism of operation is shown in Figure 4 .



Figure 4.

A spring-loaded check valve is opened by the water supply pressure when outflow occurs through the valve (Figure 4A). When pressure is sufficient to open the check valve, flow is directed into the garden hose.
When the supply pressure is interrupted or when the pressure in the hose becomes greater than the supply pressure, outflow stops and the spring-loaded check valve closes, simultaneously opening a vent to atmosphere (Figure 4B). In this mode of operation, any water that flows backwards through the HVB is vented onto the ground.

The spring-loaded check valve does not allow drainage of water from between the hose bibb and the upper part of the HVB. Thus freeze protection must be provided, just as all outdoor plumbing would need to be protected under freezing conditions.

The typical hose bib with built in vacuum breaker, like the one referred to in this post, works without the use of springs.