SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Do you have a Maxi-Paw tool? It unscrews the innards of the sprinkler.
Be careful to not damage any of the working parts while unscrewing and replacing the innards.
There could be debris causing the seal to leak.
I would unscrew the innards then flush it out by turning on the sprinklers. Use your hand to help any pebbles to escape.
Check to see if it can pop up and down freely looking for grit.
You can clean the inside of the sprinkler out with a garden hose before unscrewing.
If the seal is badly damaged, or worn out, then the sprinkler needs replacing.
There's also a big o-ring at the top of the threads. I've never put teflon tape on the threads but if the o-ring is bad, give it a shot.