Drum/Drum dual master question

Call these guys for the right M/C

http://www.truckandcarshop.com/

 

You guys keep guessing about this guys truck. The master cylinder is nowhere near the firewall on a 59.

He needs to first get the right MC

 

I think he is putting a dual master cylinder on it to replace the single.

 

Well that explains it...nevermind

 

I hope this will help
http://www.piratejack.net/index.php?option=com_content&view=article&id=11&Itemid=18

 

This picture has been shown before, and it's still wrong! Metering was never, and should not be used on drum/drum systems. Secondly, you don't need two residuals to the fronts, just one before the tee.

 

V8 Bob
Thought I was going to prove you wrong so I took the old one I had apart so I could take a photo. I am not worthy, you are right.
LOL

 

Ok
Dual reservoir drum/drum MS. 63ish AMC.
Running all drums.

I see what spears to be pressure valves or not?
This MS isn’t technically under the floor and just barely above wheel cyl level.
Think I’m gonna plumb it as is and see what happens.

 

This page has a plumbing diagram for drum/drum master near the bottom of the page:
https://piratejack.net/tech-support/

 

If you gently poke thru those brass seats with the shank of a small drill bit, you will easily be able to feel if that master has residual valves built in.

 

Go here and read, or even look at pictures.

https://www.jalopyjournal.com/forum/threads/tech-week-57-fargos-brakes-101.1229211/

 

@pprather and @V8 Bob


I’ve seen this diagram before but I’ve never set up one like this. Seems strange.

I plan on checking my MS to see if it has valves in the ports.
@57 Fargo thanks for the write up.
I’m a collision guy, so thanks for making it simple enough for us body guys to grasp it. I’ve followed diagrams and copied the factory stuff. Nice to have explanations

 

The picture and description came from where? I think BS as it is in total very strange..

 

Another myth exposed

supposed to be AMC tech info for the MS I’m using.
The port furtherest away from the pedal works the front brakes if not 1 inch bore.
Posted this for the folks that think it’s only for rear brakes.
Shows 2 check valves for 1 inch bore. (4 wheel Drum brake)

 

Total old wives tail that keeps getting propagated. The two purposes for a residual valve is to prevent fluid from running back to the master if it’s lower than the wheel cylinder or to prevent air entrance upon brake release. That’s it. 10psi will not come close to overcoming the return spring pressure.