I was attempting to bleed the brakes of the CSX and the right rear would not bleed due to a blockage. A few moments of troubleshooting and voila the proportioning valve was blocked.
Let's clean it up...but first lets figure out how it work and google was very little help and any references were of little help. After disassembly and cleaning the valve, I am confident it will be fine going forward.
Any one have a good reference for how these work??