Sounds like the bleeder screw. Look here:
Sorry, maybe I was not clear here. The "threaded nipple" is a part of whatever it is. The threads are exposed, so whatever screws on there is misssing. And the threads are still clean, indicating it is relatively new.... But beside the line from the front the is a "threaded nipple" that is missing a cap or plug, or ??? and is the source of the leak. What part is this part, and what's missing from it??
I don't know. I am just guessing as that is the only thing I can think of that might resemble what and where you are describing. This is where a FSM would come in handy.O>K> so if it is the proportioner valve...
what is missing from it?
do I need to replace the valve?
No pic! Try to post it again.here's a pic, the "connector" in the middle springgs the leak.