>Follow the two pipes from your master cyl. You'll
>see they run into a little block, then on to the wheels.
>That little block has a shuttle inside. Under hard braking
>if one side fails (one line has high press. the other not)
>the little shuttle will shift to one side, sealing off that
>defective circuit.
*****************************************
Contrary to what a lot of people have been lead to believe about the
operation of this little valve it does NOT seal off any lines when it is
forced over to one side or the other it's exactly what it's title
designates, a Pressure Differential Warning Activator. That is it warns
you via a light on the dash that a pressure difference exists in the two
lines that it's connected to. That's it's sole function. It is merely a
hydraulic shuttle/switch. The two lines in the system are supposed to be
completely independent of each other.
Having said that, as for how dual systems are *supposed* to work is that
one system would fail before the other giving you at least partial braking
and a warning that something is wrong, GET IT FIXED NOW. In actuality, I
have never found it to work as it *should* and I have commented on the very
same thing you have as far as bleeding. In my experience, on the rare
occasion when I've had a failure, it went to the floor, no warning, no
brakes - NO FUN :-)
Barry Schwartz (San Diego) bschwart@pacbell.net
72 PI, V6 Spitfire (daily driver)
70 GT6+ (when I don't drive the Spit)
70 Spitfire (long term project)
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