Hot Rods Drum/Drum MC

Any difference which goes to front or back? Dual MC.

 

Yes. According to some brake scientists. I’ve always plumbed it like the OE. When swapping to a dual MS I plumb it like the OE did on whatever ride the new MS came from
look up the master cyl being used.
I’m using an AMC dual MS. The drum/drum version vs the disc version swap which port is for the front.
or opposite the rule of the rear of the MS going to the front.
The standard rule for disc/drum is that the larger reservoir is for the front discs
Front wheel cyls are generally larger than the rear.

https://www.jalopyjournal.com/forum/threads/drum-drum-dual-master-question.798136/

 

I don't know of any reason to worry too much about which side goes where, as they have the same pressure at both ports, the reservoirs are usually the same size, and fluid is fluid....

 

My personal preference is attaching the line to the front brakes to the port closest to the M/C mounting flange so the fronts get the first bit of movement of fluid in a tiny split second. Down to the brass tacks it does not really matter since force through the hydraulic system is equal anyway, I just do it that way for me.

 

Service manual for the MS I’m using

why they specify which one?
Don’t know.
Just plumbing it like the book says

 

That's a disc/drum MC, so they specify that you don't use the residual pressure valve with disc brakes.

Notice that in some cases the front half is for front brakes, other cases the rear half is for front brakes. As if it really doesn't matter?

 

used on drum/drum in 1 inch bore form.
Used a a disc/drum in a larger bore.
check valve also changes.
Definitely specifies which reservoir is used for both set ups

 

Some master cylinders are timed internally to apply the front brakes first. Others don't matter at all. It is always best to connect the ports the way the factory did just in case.

 

That’s my thoughts.
Enough info out there to find out how it was designed to work