So I bled my m785s today using the epic bleed kit and it all went smooth for the back, but once I got to the front, at the last stage when you flick the lever the bubbles never stopped coming. So I eventually have up and stuck the bolt and oring back in. I then noticed there was a squelching noise and fluid leaking out all round the chrome lid thing.

Is it new lever time or is this just excess fluid escaping?

Sounds like a leaking diaphragm (seperator unit in Shimano speak), available via Madison from your LBS, part no. 8VC 9806 at £2.99