Sluggish keys

[jere fryett]

Dear List,

Today I was tuning a 1941 Haddorff and noticed that the keys were quite
sluggish when the sustain pedal was used.  The keys seemed normal without
the use of the sustain.  I also remember this happening in other pianos.
What causes this and what is the fix?

Thanks,

Jere Fryett
PTG Associate