[MikeB]

Originally Posted by dmjlambert

I suggest check with White Post restorations, that is where I sent mine. Getting it rebuilt may be a good idea on an old valve even if it doesn't solve the problem.

Rubber brake line close to exhaust and getting the heat may be failing, so the rubber line that you haven't replaced yet would be my first suspect.

In my experience I did not have to disable the metering valve as they mention to do brake bleeding nor to do this test, and to bleed also did not need to use the so-called brake bleeder tool that replaces the switch and holds the pressure differential valve in the middle position.

I will contact White Post, because I like the idea of having an OEM spare.

The rear brake hose is not close to the muffler. The muffler is close to the frame which prevents getting inside the frame with a wrench. And again, the hose looks like new, as do the rear shoes and wheel cylinders. One of the shops my son used must have done the work.

I had the same experience as you (no problems) with bleeding brakes in the past without holding the pressure diff valve in the center -- on my 69 at least twice, and on an 82 C10. Ignorance is bliss!

Final Update: The new valve is installed and the rears bled just fine. The pedal feels a little different, but in a good way. It has a little more progressive engagement, whereas before it was more sensitive.