Diagram of the Pressure Differential Valve/Proportioning valve assembly from the service manual for the full size Mercury. I had to replace both of these due to the brake problem I had when I first got the car (see log). The proportioning valve I got as NOS from Ebay, and the pressure differential valve I got from Erik's '69 Marauder that he is parting out. In the meantime I got the old pro-valve, and pressure diff-valve rebuilt by White Post restorations, which are on the shelf in stock.

Owner caption January 2020 · Photo 28 of 466