Here's the things I saw and what I did.
The linear travel on the clutch slave piston/rod was pretty much exactly on spec - 14mm. But still, I've checked the linkages etc in the system. I didn't think that would be an issue as the car has only done 3500 kays. Perhaps these clevis pins and MC rod stirrups are a hell of a lot softer than they used to be!?!?
I took out some under carpet firewall insulation as that was limiting pedal travel due to being extra padding
Plus the long steering rack bolt was limiting pedal travel
So I ground them back
This gasket looks super thick so I removed it in case it was taking up too much MC stroke before it moved the plunger (smeared sealant instead)
I replaced a pin which was worn
The hole in the MC rod stirrup is also worn. I left this as is but plan to remake the stirrup in proper steel and weld on to the MC rod. Also the clevis hole in the pedal is a little oversized, so I could weld and re-drill that too.
Here is the thrust face you recommended I check. All worn from previous thrust bearing blowouts. Does it look a little dished in from heat + pressure? And what do you think about the true-ness...slightly lopsided perhaps? Hard to tell.
I dug around and replaced it with the component from this ancient diaphragm
So how did it end up after all of this? Well in order to have the clutch not drag when I pushed the pedal all the way in, I had to reduce the lever return stopper from 0.5mm gap (as in the manual) down to 0.2mm. I tested clutch drag by starting the car with the front on chassis stands (wheels off the ground), keeping my foot off the brakes, the car in gear and the clutch pedal fully depressed. I adjusted the lever return stop until the front wheels would stay completely stationary while doing that test. Thoughts on whether this is appropriate are welcome. I wanted to do this as a way to see what was ACTUALLY happening, rather than just set factory specs and drive away.
It seems like it is not completely sorted if it can't be at the factory specs. Perhaps I've been able to thread the needle and find setup that works. After a bit of a drive I will re-check all of the setup. I will also rebleed the hydraulics to eliminate that.
The clutch is juddering a little (only when half engaged), not surprising as there is a thin coat of grease on the clutch components from the bearing crapping itself. Maybe there is something going on, like a shard of old bearing lodged in the disc or something that is reducing travel? I dunno just thinking outside the square. I hesitate to undo the diaphragm to check/replace the clutch as I saw an MED video about how a small variation in mounting the clutch components can throw the system quite a way out of balance. And I had the whole system all balanced up at the build stage.
