A mate has got some xtr dual control rapid rise on his bike, they must be a few years old and I'm sure there is air in the system so going to try and give them a bleed. We turned the bike upside down to take wheels out and the levers were spongy after. Have zip tied the brake levers to the bars to see if that'll help.
I forgot to look for the model number so I can see if there's a vid guide or can talk me through it, anyone know it?
I'm guessing that you bleed from the caliper up but it's a different process to the newer types.
TIA
Ideally get a Shimano Bleeding-Kit TL-BT03
Bleed from calliper up, then use the lever to flush fluid back through the system and vent it via the bleed nipple.
If you need any additional help give us a nudge here:
http://www.epicbleedsolutions.com
I think his brakes are M965s which they say you do a conventional bleed from the top down?