Hi Iggy,
I do not have access to star atm. If this is the profi MB software then of course (being in Germany) I can go there any time. Before I do that I want to eliminate a few things by hand since they take vast cash for even breathing in their depot.
The dual mass was brand new, clutch and everything new (12mm) by sachs. It was one hell of a business finding the right parts since this constellation of motor and gearbox (I found out the roundabout way) is only to be found in Brazil! no records at all with DB in Stuttgart. I found an engineer who had kept his personal records, and told me a golden rule. "The clutch parts must be matched TO the dual mass first and foremost" which means from the engine backwards. Mixing parts or manufacturers is generally not a good idea, but in this case I had a choice of two DM flywheels. The rest I chose to fit one of them based on the original MB part I removed, all from sachs, who I spoke to in Poland, and who could tell me nothing really useful.
There is one thing I want to try since I think that the problem, as you say, is air in the system.
I have noticed that the low pressure feeder pipe to the pump is generally wet with oil. No hydraulic system can function correctly with air sucked into the hydraulic pump. I suspect the plastic tube from the sump to the pump, which I am going to replace with some sort of improvised tube, maybe a fuel line or a brake line if I can find one around 10-11mm bore. As I said the oil was always frothy whenever I bled it through the bleed port on the slave. This suggests that the pump was mixing, and building up the pressure with oil and air. This would make the action of all the gear shifts questionable, but especially the slave movements at the pull away start, because here the torque difference is greatest.
From your experience, if there is air in the line to the slave (or froth), can this escape with repeated clutch movements by being forced back each time into the valves, or will it be there forever until I bleed it out of the other end? I have read that the whole system can breathe, but how on earth can the high pressure line to the slave breathe? surely this must be filled with pure oil without any air in it...? When you bleed the system do you see froth?
Can you tell me offhand if the bore of the sump outlet (11mm) and the bore of the pump inlet are the same? that would be helpful!
I will report any success with this.
Best,
Bruce