I just replaced the rear heater valve. I bought it from the dealer with the
"O" ring $48.58 for both plus tax ($3.75) and replaced it. I only lost about
2 or 3 tablespoons of coolant. A very easy to do job.And simple. It took
about 10 minutes.

When inspecting the new valve I noticed that there was a tight fit and
virtually no clearance between the valve and the housing for a very tight
precision fit.

Inspecting the old valve I saw that it was loose, dirty and there was
significant space between the valve assembly inside and the housing, about
1/16 inch on both sides. The valve must have shrunk over the years.

I did attempt to bleed the system at the rear heater core but got virtually
no air which puzzled me. With a loss of about 3 tablespoons of coolant there
should have been some air. Any advice about that?

I thought I would write this progress report in case anyone checks the
archives in the future.

William