Yeah, yeah; now I remember! Thanks for the memory jog.
I went through this about 10 years ago - the solenoid can't move the piston against the coolant trapped above it.
It's Hell to get old and forgetful, and have to retire and play golf all the time!

I'll fix it and report back.

Oh, one thing I do remember; I promised David a lunch about a year ago. I WILL get by there I promise. It's just a long drive from my house these days.

Cheers,
DG