Its on the inside of the 6-speed box's.
Its part of the release bearing, Its uses a CSC. I have just replaced the one in my LCR and its a Gearbox off job.
How are you trying to bleed the system?
You can gravity bleed them, just crack the nipple and let the fluid drain through without pressing the pedal,
Pull the pedal up and leave it up with the nipple cracked. Once fluid comes out tighten it up.