Reply to "Brake fluid change"

The brass 'safety' shuttle valve mounted below the power booster can and has shifted to one end of it's valve body during vigorous brake bleeding. This severely restricts or even shuts off fluid flow to one pair of brakes. DeTomaso, alone among car manufacturers that use these valves, included no internal return springs for the movable shuttle. So if the shuttle moves too far in a used valve (which always has varnish buildup inside), the shuttle may become so firmly wedged in an end that you will wind up with essentially NO brakes at one end of the car!

The shop fix is to disconnect the hydraulic lines, remove the valve, inspect for shuttle position and if required, blow into the outlet ports with an air compressor, making allowances for the spray of paint-removing brake fluid that will also happen. The shuttle position can be seen thru the hole for the stoplight switch if the valve is removed from the car. As installed in a Pantera, with the stoplight switch valve port facing the firewall & underneath the booster, even a lit inspection mirror doesn't work. The air pressure thing can be done in the car, but you WILL get brake fluid spraying around, and the shuttle may move back to center- or move too far, to stick at the other end of its travel.

All this is among several reasons I suggest removing that valve and put it on a shelf somewhere, far away from the car. Re-plumb the system without it so the brake master cylinder still supports two separate front & rear brake systems, as req'd by the U.S. DOT since 1968 for safety.