Disc brakes do not need appreciably more fluid to apply.  The reservoir is bigger because as the pads wear, the pistons move out in their bores to compensate, and this requires extra fluid.  Once they have compensated, the volume of fluid for application remains the same as before.  The reservoirs are bigger so that you don't run out of fluid in the master cylinder shen you don't check the fluid often enough.  Drum brake pistons do not compensate for wear, adjusting the brakes compensates, the pistons remain in the same position.

John - "The Hoosier Hurricane"

Although ‘Old Y Block’ hasn’t been logged on since he posted, based on the original inquiry the car has a single reservoir master cylinder on it now and he simply wants to switch out to a dual reservoir master cylinder.  He doesn’t mention if disk brakes are being added but if not, then in this case a disk brake master cylinder could be made to work.  The proportioning valve just would not be needed if the car is still drum brakes.

 

Without a make and model, knowing exactly which master cylinder to retrofit is indeed difficult.

Lorena, Texas (South of Waco)

I may have this backwards, but don't disk brakes require more fluid than the drum brakes, isn't this why on disk/drum set up the disk side of the master cylinder is larger?  If so, then would it really matter if you used a drum/drum versus a disk/drum master cylinder? 

Old Y-Block: lot of advice here but, maybe you should start at the beginning.. what year & model is your vehicle?..

Paul

Your original was 1".  Going to a 7/8 will give you more pedal travel to apply the brakes, but an easier pedal to push.  Going larger will give you a high, hard pedal and a car that is hard to stop. 

John - "The Hoosier Hurricane"

O.k.  I know this topic keeps coming up, and I've read through a few posts.  But without power brakes do I want a 7/8" bore master cylinder or a 1" bore?

Won't 7/8" give better pedal travel (pushes less fluid per inch of stroke) and higher pressure at the same time? 

I hear the master cylinder options for drum/drum manual brakes are

68 Mustang?

68 Bronco?

67 Falcon?

Do any of these come in optional bore sizes?  Or should we assume since they were designed fro drum brakes that whatever bore diameter they have is good enough?

Nate - Madison, Wisconsin

 

56 Ford Customline Sedan

 

Try to get a M/C for a 1967 Falcon...non-power drum brake. They have a 1" bore, equal size reservoirs.

FIGHT CONFORMITY! 

Try one for a Mustang. I am sure one or two years might have it. Check the Mustang parts suppliers for a drum/drum dual master.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

They dont list a master for the Granada with all drum brakes.74 Comet maybe?

  

68 ford bronco manual all drum

y-block newbie