FJ40 1974 stock brake advice

[gbp808]

Hi, I have drums front and back, tandem master cylinder and "new" type booster (master bolts onto booster). I have replaced/rebuilt all wheel cylinders, new pads, and replaced master cylinder. Problem is persistent soft pedal. 1st pedal depression goes to floorboard, but it gets good pressure after 2-3 pumps and the pressure will hold if the pedal remains depressed.
No change with engine running.
No apparent air in the system. Capping the master cylinder brake line ports results in no softness to pedal, firm on first push, and holds.
No leaks.
Any thoughts on where I should look for a problem?
Appreciate any thoughts, please and thanks.
garry

 

[Pighead]

adjust your shoes tighter.

 

[charliemeyer007]

So how did you bleed the cylinders. If you used a mighty vac or other vacuum bleeder - there is good chance you were sucking air in threw the poorly made threads on the bleed screws. Use Permatex on the threads or even better do the 2 person method correctly. Set the shoes out to lock the drum lightly - (drag hard) - mash on the brake pedal hard several time to center the shoes - then set the shoes out farther to lock the drums for bleeding. Start at passenger rear, driver rear, passenger front, drivers front. Now move the shoes in equal clicks at each wheel so the wheel barely drags.

Out of round drums can cause issues.

 

[peesalot]

Adjust the shoes with wheels bolted on & tight not just hand tight. Set the rears with a bit of drag, drive around and use the brakes a bit, see if rears are way hot, if so back em off a notch, if just warm then your close, let em break in. I found that it took some work to get the rear shoes set & broke in. IIRC never got rid of the double pump tho. I had same dual circuit MC w booster, drums all 4. I have always had luck gravity bleeding all 4 corners at same time. Keep MC full with cap off, close the fronts first when both start running consistent fluid. While rears are running consistent fluid rap on the first wheel cyl to try and burp air thru if any is in there then close em up. I use a piece of vacuum hose and a water bottle at each corner to avoid a mess. I assume the new MC was year correct thus having the residual valves in it ?