Bleeding XT brakes – the Shimano way with reservoir tool – air in caliper?

Does the rear caliper have to be really low in the system when bleeding to get any trapped air out?

I’m following the Shimano instructions, and when I get to the “press the lever, open and close the bleed nipple in about 0.5 seconds” part, the lever pulls straight back to the bars again once the nipple is closed and no amount of pumping firms it up. I can then firm it up by sucking fluid back out of the caliper with the syringe, but opening and closing the nipple causes the same issue each time. I reckon there must be air in the caliper that I cant shift.

The front brake is fine.

Also, I’ve tried bleeding with the free stroke adjuster in and out, and it seems to make no difference. All I’ve learnt is that you can completely unscrew the adjuster from the lever….

Still, great brakes for £75!

Close the nipple, squeeze the lever and hold it there. Tap the caliper and hose all the way up to the lever.

Zip tie the lever to the bar. Leave overnight. Then try again opening the nipple until the lever just starts to move. Great brakes as you say!

Have you flushed the brake with fluid using the syringe and funnel first?

I had a little trouble with one of mine, took the whole system off the bike, held the lever in the vice (gently) so that the reservoir was level then cracked off the bleed nipple & just relied on gravity, worked a treat.

I propped my bike up with lever at highest point, and spent 5mins tapping up from caliper, up line to lever. No joy.
So then I just reverse bled it – sucked out of caliper and a pile of bubbles came out. So I then pushed fresh oil back in at caliper and upwards as normal – and it is perfect now.

I’ve just got these brakes and I’m having issues with my rear one. Matt has the best method that seems to work every time.

These brakes are no way as good as the Formula Oro they replaced.

have a look here

and here

The epic bleed solutions bid is useful too