[MTemp]

Not sure if the 68 912 has a single or dual m/c so please adapt this process if necessary. With the single m/c one outlet feeds the LH front (I think) and the other the RH front and both rears. Get a spare calliper bleed nipple, or bend over and crimp a piece of brake line in a standard brake fitting so it's completely blocked. Use this or the bleed nipple to block one of the outlets (I used the RH front/both rears). Now bleed the LH front by your preferred method. If the pedal is hard and the front LH operates properly you now know the m/c and the LH front is ok. Now use the bleed nipple to block off the tee to the rear callipers and check the RH front. Again if OK you know the issue is with the rears

etc etc until you isolate which component is the issue, and you can then address accordingly.

From my experience if the whole system does not bleed relatively quickly then it never will - there is a fault somewhere and you need to use this sort of process to isolate it. Indeed you can start by putting bleed nipples in all the m/c outlets and just bleed the m/c. Big advantage is you can do it with the system in place.

Good luck. It is a thankless task and brake fluid is awful up your sleeve!

Mick