[Michael F]

I pulled the master cylinder and proportioning valve. I took the ends of the prop valve and there was some stuff hardened up in it, didn't pull the plunger out of the master cylinder. I hit one of the prop valve caps with some scotchbrite pads and whatever it is hardened up on it just tore up the pad, so I I'm going to go ahead and replace both.

Edit***
I've searched online and can't find a prop valve, I did find a rebuild kit which will hopefully do the job. I'll have to see if I can get all the pieces fully disassembled. They recommended soaking it in ammonia for several hours to assist with cleaning. Sounds like another project for next weekend.