Need brake help..

[slickstysix]

Hi Guys
So I have a 66 F100 that originally had manual brakes with the single reservoir. I changed it to a new 67 F100 power booster (8" dual) with a dual reservoir for disk/drum. I had intentions on putting the disk setup on, but the Halibrand wheels i have wont' fit the rotor hubs.
My question is, the brakes don't take until the last 3 or 4" of travel and then bottoms out before I can come to a hard stop. I've adjusted the shoes on all 4 to slightly drag on the drums, but it doesn't give me any more pedal or stopping power. i"ve also adjusted the linkage in and out with very little change.
Is the power booster/dual reservoir built with a shorter stroke?
Thanx in advance for the input.

[Blackwaterforge]

Is your mc a drum/drum or a disc/drum?

[Blackwaterforge]

Reread post.
You need a drum/drum mc

[Toyz]

You don't necessarily need a drum/ drum master; just need to add (or be sure your m/c has) 10psi residual valves to both front and rear systems. These counteract the springs on the shoes to keep the lining in close proximity to the drums.

[slickstysix]

@Toyz - Where would I get such valves? I assume they can be plumbed inline?
Thanx for the tip.

[Toyz]

Yes they are widely available in the aftermarket from Wilwood and others. You need the 10 psi versions. They can be plumbed in line.

[slickstysix]

@Toyz - thank you very much!

[slickstysix]

So what is the difference between disc/drum and drum/drum master cylinders?

[slickstysix]

Also, where do I install the valves? At the MC or does it matter?
TIA

[Blackwaterforge]

Drum/drum mc will have correct residuals.
Also compartments will be equal.
Getting the correct mc is a easy solution

[redstone65]

@Toyz - Where would I get such valves? I assume they can be plumbed inline?
Thanx for the tip.

This is the valve you want: https://www.amazon.com/Wilwood-260-1370 ... 015NNPUS0/

Technically you could plumb them in anywhere, but right near the MC is best IMO. Makes service and leak inspection way easier.

I agree with Blackwaterforge though - swapping the MC to a better one seems like the correct first step. See my post here, for a NAPA MC part# that works fine on my '65 all drum daily driver. After putting in a known, appropriate MC, you may find that you don't need any extra valves or anything like that. I don't have a booster on mine and it stops just fine.