Hey, I'm going to attempt to upgrade the brakes on my '62 Monterey from single circuit to dual. It's currently got Drum/Drum with a single bowl attached to a booster. So far i have learned that i need a 67-70 Galaxie Power Drum/Drum (equal bowls) master cylinder with a 1" bore? However I've had mixed advice regarding proportioning valves. Some have said it's not necessary whilst other have said it's imperative. Is there a setup available for my car that doesn't require a valve or is it just a myth? Thank you for your time.
Upgrading to a dual/tandem master does not change the brake balance, just provides the safety of two hydraulic circuits instead of one. Proportioning valves were never used with drum systems, but are required for disc/drum (and some disc/disc) systems. What is needed are residual valves with pre-'70s drum brakes, and the '67-'70 Galaxie master should have them located internally behind the tube seats. If the master you use does not have them, add an external 10 lb valve to each axle.
v8 bob, Doesnt the 10#residual valve hold 10 lb. of pressure to the wheel cylinders. Why is it needed in a drum setup?
Residual pressure (check) valves are needed on vintage drum systems to keep air from entering past the wheel cylinder cups (partial vacuum) during fast brake release because of the strong shoe return springs. By the middle '70s, cylinder cup expanders and common front disc brakes made the residuals obsolete. (Production disc brakes never used residuals because all master cylinders were firewall mounted in the '50s, before modern discs became available) Production residual pressure rates varied from under 10 to about 20 psi, so the aftermarket 10 lb valve is a good compromise, and is far less than the pressure/force exerted by the shoe return springs.
I used a master from a early mustang in my 59 edsel. I would think it was the same as your car. It bolted right in, but I dont have power, and havent had it on the road yet.
This looks like a good resource; http://www.mbmbrakeboosters.com/ind...tent&view=category&layout=blog&id=8&Itemid=16
The above layout is not correct. Drum brakes never used metering valves, there's no such thing as an adjustable residual, and no reason to run two residuals to the fronts. They should be located near the master, before any other valving. MPM is also not correct on the purpose of a residual, a**** several other details. Typical for many brake suppliers that may sell good products, but don't have a clue how many of them function, or understand brake systems.
Done this swap several times 68 mustang dual master [ i think ? ] Bolts on, plug hole in splitter and ride L
I too have done this swap, 67ish Galaxie master cyl for a drum/drum system on my 64 Galaxie. Have driven it for many years now.
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