Anti-siphon hose bib

[Burford]

All my antisiphon hose bibs are leaking badly when water is turned on; water pours from the top where the green plastic cover is. I understand that there is possibly a leaky washer underneath, but I can't figure out how to get the plastic top off. (Hexagonal green plastic). Brute force, or is there a trick?

[Dunbar Plumbing]

Pop that cap off, there is a rubber O-ring that is cracked. If the whole plastic part inside is cracked, then replace it with a rebuild kit. Most times it is a rubber O-ring that has cracked and split apart; a common situation with rubber products in plumbing. Produce a manufacture's name and I can probably find you a PDF explosion of your product so that you know how to take it apart. It is like a floating check valve that prevents the reversal of flow from the hose connected to the faucet, back into the potable water system.

[toolaholic]

are metal. sound,s better than plastic

[PEW]

I have found that many times it is just debris that can be clean out.