Brake pro portioning valve

How does one attach a photo taken with an iPad without exceeding the limit ?
Basically the photo shows no front pad wear.
Sorry. Am new to forum operation.

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.

quote:

Originally posted by Punkdog:
QUESTION, does anyone have a diagram or discription of how the PV works ?

attached is a PDF of some notes I made

Below is an excerpt from our instructions when installing one of our brake kits. I think it will answer most questions:

Most cars have proportioning valves on the rear brakes to keep them from locking prematurely before the fronts. Not on our Pantera’s. DeTomaso thought it was a good idea to put a proportioning valve on the front circuit of the brake system. The reason why they did this was to try and balance the poorly designed rear brake system when it comes to brake system balance. Basically what they did was to detune the front brakes so they matched the rears a little better. The fronts were great brakes but then they detuned them because the backs were so poor. Quite a few Pantera owners have removed the proportioning valve from the stock brake system for a free upgrade to the braking performance of the front brakes (see important note below). This modification coupled with a rear brake system upgrade provides a significant upgrade for a relatively small price. The proportioning valve should be removed from your car once this kit is installed. It is highly likely that the rears would lock up before the fronts with the proportioning valve still in place. This would be a very dangerous condition that needs to be avoided.

IMPORTANT NOTE: If you purchased just front calipers and are still using the stock rears, DO NOT REMOVE the stock proportioning valve at this time. Remove it, sometime in the future, when the rear calipers get upgraded. The reason for this is because with the higher pressure going to the front Calipers (if the P-Valve was removed), the front Calipers will be stopping the car way before the rears get enough brake pressure to assist in the stopping of the car. In fact, removing the proportioning valve without upgrading the rears is basically disabling the rear brakes. This is again, because they never will get enough pressure to actuate. To get enough brake pressure for the rears to actuate will cause the front to lock up. This is the exact reason DeTomaso installed the P-Valve in the first place. A better solution would have been to improve the poorly designed rear instead of lowering the front brake pressure. What they affectively did was to increase brake pressure to the rears by lowering pressure to the front, thus achieving better balance.