Reply to "Brake pro portioning valve"

The factory proportioning valve is non-adjustable, being set by a large spring inside to automatically reduce the max hydraulic force delivered to the FRONT calipers from the master cylinder. The small rear calipers receive 100% of the max possible hydraulic force. Since about 65% of the possible max braking is done by the fronts in a Pantera, this setup is WRONG, giving away significant brake force from the 1970s racing-inspired front calipers.

Worse, the valve setup assumes the tires on the car are OEM 185-70 x 15"(frt) and 205-70 x 15" rear (optional 215-70 x 15"), on 7" and 8" widths, in a fairly hard rubber compound no longer used. So if you are NOT using that size and type of tire, the valve has the wrong spring besides being hooked up backwards. This is why most owners that actually drive their cars discard the stock valve and replumb the whole brake system as the designer Dallara likely intended. A manual adjust proportioning valve can be substituted to balance braking force front-to-rear once the system is plumbed properly.

All this, along with the swaybar sizes and a few other things were done (probably by Ford Engineering) to make the mid-engined Pantera behave like a front-engine Ford Galaxie for the average, untrained U.S. passenger car owner.