Brake bleeding help

Okies, after weeks of on/off working on my brakes, I'm just past the point of being stupidly annoyed.

Original hoses were knackered beyond belief, so replaced them with a set of braided hoses. This improved the feel dramatically, and made them a bit less spongy, but I could still pull the lever back to the bar on all but the number 1 adjustment level.

The brakes have now been bled for the last hour, going through almost 250ml of brake fluid. They've been bled from the master cylinder, the banjo on the caliper and the bleed nipple, but there's absolutely no change. In frustration, I took the double banjo-bolt off the master cylinder and connected each line to the MC individually, in turn, using a single banjo. As soon as I did this and bled from the bolt a little bit, I barely had to pull the lever and it was rock solid.

Thinking that maybe there'd been air at the top of the lines that I couldn't displace previously and that it was gone now, I put both lines back on with the double-banjo and bled till no more air was coming out. The lever's now back to where it started originally.

I've now only got 2 assumptions left:
1) MC is buggered and can't push enough fluid for both lines.
2) There's air right at the top of the banjos on the line closest to the MC. The crush washers on either side of the banjo form too complete a seal for any air to be pushed out at the top on anything but the other banjo, so I can get air from one line at the top but not the other.

So! Has anyone got any ideas on what to do with this, or a pressure bleeder to try to whack on it to force the air out?

Leave it open a few hours without fiddling and gravity will sort it out.

Works for me.

Leave what open? The reservoir cap? Master cylinder banjo bolt? Unsure how this would help

[Spiderman]

have you tired tapping the caliper, lines etc with a bit of wood to displace any trapped bubbles?
Also you are doiing this with the bike on a paddoc stand i assume?

Yep, tapped all over, no joy.. As mentioned above, if there's air in the lines, it's definitely at the top, since changing the banjo bolt over to a single-line setup (to pump just one caliper) then bleeding out the air that the changeover puts into the system instantly makes the lever rock-hard - you can barely pull it back more than 2cm. It's been bled on a paddock stand in the past, but the most recent bout was done on the side-stand, turning the bars side-to-side to keep the MC bolt as the highest point in the system.

[Spiderman]

well thats my helpfull hints locker empty now sadly mate.
i'm sure someone who knows better of these things will come along with some better advice soon tho.
I'd bled my brakes quite well i thought then went in to have tryes put on. They bled them during fitting but didnt mention it and i was really suprised at how much better they made them feel, so there must be some devious trick or slight of hand you need to perform somewhere along the line to get it right.

See, I'm pretty sure I'm doing things right based on how rock-solid the lever gets with just one line on. I'm pretty sure that on one disc it'd stop just fine at the moment for me to get the feel I want...but I'd like the second caliper working ideally

[Bibio]

hhmmm, are you sure that you dont have a sticky piston on one of the callipers... i have at the moment and my brakes are the same'ish.. nowt then spongy then rock hard..

Pretty sure, based on a) Cleaning them up a bit when switching the lines over and b) the switch to single-line setup. As soon as I'm only running the system as MC->single hose->single caliper they're both rock-hard. Change back to MC-> dual hoses->both calipers and sponge comes back.

[Bibio]

yup.. mine are the same, but i know for a fact then 3 of the pistons on one of the 6 pots are sticky.. connect the callipers with a single line and both are spot on.. connect both lines and crap brakes (well not so much as crap but just a lot of play before they work) where before i serviced them they were rock hard... (yes i forgot to grease 3 of the piston seals)