just finished the rebuild of the Wagner pressure differential valve/ proportioning valve (Ford part number C8ZZ-2B257-A). This is from a Dec 68 Metucheun built R code Mach 1. There is one piece on the this assembly that seems some cars may have come with, and some not....or maybe I am just missing this piece on the extra sets that I have.
The assembly drawings and the shop manual show what is called an "impulse valve" that is threaded into the top of the pressure differential valve and next to the brake light warning switch. It looks more like an adapter than anything, has a FoMoCo stamping on it with a C8AA-2B363-A engineering number stamped on it. Pictures below. I am curious if anyone knows the purpose of this "valve" or has it on their own car. Looks like it was not only used on Mustangs but other Fords that year.
My best guess is this must have been some fix that Ford came up with to perhaps reduce the flow of the brake fluid? It seems easy enough to take out and just run the brake lines without this piece, since the threads are the same on both sides. Any thoughts? Anyone else have better documentation on this?
