Question
QUESTION: Matt,
My drip zone wasn't getting enough water so I added another soaker hose with a 'Y' connector. Now I need to increase the pressure. When I open the flow control valve on the top of the Rainbird 100-DV - even a little - water starts spraying out around the valve. I've cleaned out the tube-like filter, just inboard of the valve. Is there another filter I need to clean, replace the valve, or am I totally off-track?

ANSWER: Where is the water spraying from? Is it from the threads coming out of the valve?
You should only have one filter so it sound like you took care of it.
If you can identify exactly where thew water is coming from, I'm sure I can help.

Matt

---------- FOLLOW-UP ----------

QUESTION: Sorry. Yes the leak is coming from the threads of the flow control valve - the small stem on top of the 100-DV. Turned all the way to the right - clockwise - no leak.  Turned to the the left - counterclockwise - water starts to spray from the threads of the stem after 1/16 of a turn and leaks more as the valve is turned more to the left.

Answer
That is unusual for it to leak there. My guess is the o-ring is bad and needs to be replaced. You can either remove the o-ring and go to the hardware store to match it to a replacement or just replace the top of the valve. Considering the cost of a DV-100 it might be easier to just replace.
I've attached a web link to the RB DV-100 parts breakdown so You can see what your working with.
Good luck.

Matt

http://www.rainbird.com/pdf/parts/600.pdf