Bleeding vintage Jag 4 wheel drumbrakes

[gtx6970]

Is there a secret to bleeding one of these cars , I've gone thru over a 1/2 gallon of fluid and still no pedal.
master cyl is new (not rebuilt) all 3 flex hoses are new , all 6 wheel cylinders (2 @ each ft wheel ) are rebuilt. all metal lines were flushed and cleaned

I've used my old tried and true method of pumping the brakes then opening bleeders screws one wheel at a time to allow air to excape ,close and repeat several times at each wheel

then used the service manual method to open the bleeders then pump the brake pedal with a hose attached to draw fluid back up into the system , again one wheel at a time.

Still if you let it sit for about 30 seconds the pedal goes all the way to the floor and will pump up to about half pedal with about 4 or 5 strokes

Shoes are adjusted up properly ft and rear

 

[DrEntropy]

No secret that I'm aware of... If it builds after a few pumps it's gotta have air in there somewhere. M/C bench bled? Tho by now that should be a moot point. Ill-seated fitting at the M/C? Once you build up pressure, does it STAY up with pedal effort maintained? All fittings and unions ckecked for "weeping"?

Dollars to donuts it's gonna be "sumfin' stoopid" hidden in plain sight... at least that's been my experience.

Earliest manual I have here is for the "MK-2 Models" 2.4,3.4 and 3.8 litre saloons. Pucks 'n cocoanuts for binders, no drum systems illustrated. What beast IS this? The 140?

 

[LarryK]

Bleed new master cylinder on bench before installing in car, or install without fastening lines and bleed. Air gets trapped in the master cylinder and has to be bled before install. Then start at wheel farthest from M/C and go to the next one nearer until rotated to nearest front last. But, primarily bleed M/C first to get air out. If you still have problem, then look along frame for leaks in lines.