I had all of the problems with the hydraulics/pump that are being posted
  recently and over the years.  Last August I replaced the original pump (1989
  kit) and now everything works like a finely oiled system.  Yes, it was
  expensive ($600.00) and a pain to reconfigure the installation but all the
  hiccups and headaches are gone.

George,

 

I replaced my 1989 pump about 2 years ago but did not reconfigure the hard lines - call me crazy but instead I fitted the old reservoir to the new pump.  Of course, more jiggering was required with the latest incarnation of pressure switches. Arrrrrrrgh.