Thought I posted this last night when I had finished the job. Well here it is now.
So I got distracted but eventually dragged my arse to the garage to face off with this fucking brake. I think this could be the most time I have ever spent bleeding a brake, definitely a Shimano brake! But after almost 3 hours of painfully slowly sending oil from one end to the other I emerged victorious. But at what cost? Sleep it seems.
First off, I hadn't made any silly minor errors. We have all been there - the old funnel on the front syringe on the back is a great party trick. No no not tonight ..what seems to have been the problem is as I kind of suspected early on, there was a massive air bubble in the caliper.
I switched the lines and the problem remained in the rear caliper. Then I went to town...and by that I mean I did basically the same thing on repeat for a long time. I loaded up the funnel, connected the syringe, opened every thing up, and sucked with the syringe. It sucked so hard the syringe (significantly) partially compressed! Then one small fucking cunt bubble at a tie came creeping out of the caliper, then lots, then one or two, then a big one...I wish I had of had something else to do! Id let it rest and manoeuver the air bubbles into one big air bubble that I could push out of the way. Then I would force it all back up to the funnel. The amount of force I was applying to move the baby oil in either direction was unbelievable. A few times I was compressing the syringe with both hands! Just incredibly stubborn. Eventually a few significant bubbles came out. A few times I spilt a little oil. Fuck I was glad to not be using the dot fluid range. Now my hands are soft and it's time to reward myself with a wank and a sleep