I have just swapped some old style SLX brakes to a new frame which was longer than the old frame so I fitted a new length of hose with new olives and inserts at both ends. I have been totally unable to get them to bleed properly. I have tried back bleeding with a syringe but no fluid seems to go in forcing the connecting pipe off the nipple. I have tried sucking fluid through using the syringe and brake lever opened - this brought some air and fluid through but not enough to move pistons. I of course tried the conventional method with no result. The weird thing is that it feels like there is loads of pressure at the lever to the extent you can hardly pull it in but no action further down the system as if there was an air lock.
Help please this is driving me mad!
Have you tried it with the caliper off the bike, just dangling from the lever? Could even try leaving it like that for a few hours first.
I'd guess you mucked up putting the new olives/inserts in?
thegreatape - yes i have had it dangling all night with the brake lever zip tied up
b r - I am beginning to think this must be the answer. I probably have a spare olive/insert in the shed so I'll try that next. Thinking back when I bought the new hose the shop didn't have any Shimano hose and sold me Hope which certainly appears to be the same internal and external diameter so shouldn't make any difference
i would have that lot apart to check the connections you have made.
incidentally, if there was an air lock, the lever would feel spongey and or pull right to the bars as the air can be compressed, unlike the hydraulic fluid.