I purchases a new PGP pop up sprinkler because the cap on the old one cracked and could not be secured to the outer shell. Rather than dig out the old shell, I simply took the riser out of the new one and put it into the old shell. From all appearances the new riser and cap are identical, and when I screwed it on it seemed perfect, but water sprays out sideways between cap and shell, as if there is a seal missing between the cap top and the top of the shell. any ideas? there doesn't seem to be a...
