The caps do break sometimes. Repair parts are getable though. When the cap is off, you can unthread the lower part and put the parts back in order. Sometimes the parts get crooked in the chamber.

: They are generally repairable, depending on the brand of the products. The top cap generally snaps off, allowing you to un-thread and replace the vacuum breaker assembly.

: Good Luck

:
: : I installed 3 non-freeze sillcocks and one leaks water through the anti siphon plastic cap when I attach a hose with a sprinkler or any other restriction. Is this repairable? or do I have to replace the sill cock? If repairable how do you take the valve apart. It seems that the plastic cap cannot be removed without destroying it.