Paul:

You're right.  I revise my thinking.  Discs don't need residual valves, drums do.  Thanks for bringing that to light.

John - "The Hoosier Hurricane"

Unless I am mistaken, all drum/drum masters had a built in residual pressure valve. Masters for disc/drum and disc/disc do not, residual pressure being handled by the separate combo valve. Not being an expert, any problems there???

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

It's my thinking that the disc master cylinders have the larger reservoir because as the pads wear, the pistons continue moving out of their bores and that volume has to be replaced by fluid.  The pistons do not retract.  Drum brake pistons retract, so they do not require constant replenishing of fluid.  So if you use a drum master with discs, check your fluid level frequently and top off as required.  The larger reservoir reduces the frequency of fluid checks.  Like Charlie, I see no problem using a disc master on a drum car.

John - "The Hoosier Hurricane"

I think you'll be alright using a disc cylinder with drums. I'm currently using a disc/disc master with a disc/drum setup. I switched from a disc/drum master to the disc/disc master a few years ago and noticed no difference in the stopping ability - everything else being the same at the time. In my research, I've come across nothing that says you cannot use a disc master with drums. I have found several sources which say not to use a drum master with discs.


Lawrenceville, GA

at the moment it has drums but that doesnt matter because the frame isnt under it

but  if a person would use a disc master on a car with only drums wouldnt the larger master cylinder bore/piston give better pedal feel and maybe just a tad more stopping power?

approximately how much push rod lenth difference is there?  thanks for your help

57 sedan

60 thunderbird

69 mustang coupe

69 roadrunner

i hope one of you knowledgable people on here can help me

i either read somwhere or heard  that a person can use a master cylinder from i think it was an mid 80's explorer on a 57 failane/sedan body  i think is supposed to be a direct bolt on  and its made from aluminum and the lines are toward the outside of the engine compartment 

does anyone know if this is right? or am i again mistaken  i might have read about this in an article in a magazine

57 sedan

60 thunderbird

69 mustang coupe

69 roadrunner