air in clutch line

[luna negra]

So I did a complete swap on all the fluids on my '98 Standard. Now, clutch will work fine til it sits and cools down, then it begins to slip excessively after it warms up again.   When it starts doing this, I can give it a quick bleed and it's fine til it cools off again.  I just barely have to crack the nipple (while holding the lever in) to get the clutch working again so this suggests to me that air keeps getting in the system.

I've flushed the entire system probably 10 times using a MightVac and also by just manual method so I don't think there's any trapped air in the line.  The master cylinder gasket looks OK with no knicks or cuts.  Any thoughts from the group on this?  Thanks!

[WintrSol]

That is a symptom of the pressure relief hole between the reservoir and master cylinder being blocked, preventing expansion of the fluid back into the reservoir as it heats up.

[luna negra]

That is a symptom of the pressure relief hole between the reservoir and master cylinder being blocked, preventing expansion of the fluid back into the reservoir as it heats up.

Thanks was the problem, thanks!