prop vavle or no prop valve

ok all you mechanical wizards out there. I have a 1966 ford country sedan wagon with power disk brakes, but it has a single resevior master cylinder. I want to put a dual resivoir on it. do i need to install a proportioning valve between front and rear brakes. and how the hell do you spell resivior resivore

 

A single pot master cylinder has a residual pressure valve that maintains a constant 10 pounds of line pressure at all times. A dual pot has a 2 pound pressure valve for the front disc's and a 10 pound pressure valve for drums. By using the single pot master cylinder on a disc/drum set-up you will cause premature wear of the front brake pads due to the added line pressure going to the disc's. It's nothing extreme or catastrophic, just premature.

Several years ago, I converted the brakes on my '58 Dodge Coronet to front disc's and kept the single pot M/C for about 3,000 miles or so. The wear wasn't bad. I later converted to a dual line system for the added safety and piece of mind. If you do decide to convert to a dual pot system, have the parts counter guy ensure the pressure valves are installed in the new master cylinder as not all remanufactures M/C units will have these valves. Should you install the new M/C without the pressure valves, you'll find the brakes work fine however begin to apply half way through the pedal travel.

 

my 2 bits....ive done it a few times....just throw a 68 mustang dual master at it !

 

How can i tell if they are there. I bought a MC two three years ago for it that i have never installed

 

http://cgi.ebay.ca/Power-Brakes-FOR...kparmsZalgo=SI&its=I%2BC&itu=UCI&otn=10&ps=63

That's a new one, but you can get used ones for much cheaper as well.
Junkyard.

 

I googled Master Cylinder Residual Valve and after some searching, came up with the below link. It isn't an exact diagram of a sixties Ford M/C, but it shows that approx. location of the valve.


http://www.championtrailers.com/remove_residual_valve.htm

 

wow thanks hullinger. thats what that thingie is.

 

You could always get an adjustable valve from Summit, Jegs , etc. Just plumb it into the line going to your rear brake. http://www.jegs.com/i/JEGS/555/63020/10002/-1?CT=999

 

or if the M/C is not equipped with the valves, you can plumb the 2 lb valve in line to the front brakes and they make a 10 lb for the drum lines.

just be careful as these are all 'directional' they only flow ONE way.

http://www.summitracing.com/search/?keyword=2 lb residual valve&dds=1