How do you fix a leaking lawn sprinkler head?
Lawn sprinklers leak because the water source/ valve is not shutting off completely. – You will have to clean, repair or replace the solenoid valve on the line that leaks. – I have a major brand (flies in a storm) system and most of the low voltage solenoids leak. Wish I could be of more help, but the bottom line is, plastic valves will eventually leak.