Rebuilding rear brake master cylinder - help (696)

whilst 'bench bleed' will make things easier for sure, if you are patient you will normally find that you can bleed in situ and a total airlock within master is rare. You can get a lot of the initial air to rise up to the reservoir with constant pumping of lever watching with cap off as each bubble emerges. When you feel this has subsided you could try conventional bleeding of slave depending how much fluid was lost from rear hose when you broke the joint - I always loosen union a quarter turn initially while bolted up and then remove master and reservoir if possible and then remove holding higher than slave/hose run with cloth nearby to avoid paint stripping. Then you can tiewrap rear hose up high so no fluid lost. Re-connect as high as poss also - (can't remember how much 'slack' you have on your rear hose though) you can leave last adjustment of hose union angle until it's fully bolted up. Best bleeding method if air still suspected is to pump say 5 times rapidly and hold lever down then open bleed for a split second and hopefully air and fluid will 'spit' out. Just repeat over and over. If you still feel you have a long lever then you can start to juggle components to help the air leave - sometimes output hose on master is at lowest place rather than highest so unbolting and swivelling will allow air to escape to reservoir again while pumping. Ditto slave - you can unbolt it and swivel/lift higher than master during bleeding etc. Are you still awake others will probably add their own methods - pressurising system can save all of this on some occasions.