I bleed the clutch and all seems well for about a dozen shifts or so but
slowly I seem to lose it again.  Rapid pumping of the pedal brings it
back for a bit, enough to get home.

I've never had a master or slave cylinder fail without leaking but I
suppose that is not only possible but likely given what I'm seeing.  The
questions:

Is there any way to determine whether it is the slave or master that is
failing other than replacing one and seeing if that helps?

Is one more likely to fail than the other (both have about 40,000 miles
on them).

I think I'm bleeding adequately (& have replaced the fluid - all DOT3)
and the archives make no note of any special requirements, but... has
anyone experienced difficulty getting a good bleed on these?  ISTR some
British cars require back-bleeding if an air bubble gets into a high
point in the clutch hydraulic line.

TIA for any suggestions.

Geo Hahn
84 Westy