Air in the system give a distinct spongy feeling. Master cylinders often come with little plastic fittings you screw into the outlets and run the fluid back into the reserviur along with any air in it. You then reconnect the lines and bleed all around.
A solid low pedal can be a rear adjustment problem. If partly applying the parking brake fixes the problem, it is the rear adjustment. The self adjusters have never worked on anything I have ever owned going back to my 68 Chevelle. Pull the drums. Have them turned or grind the ridge next to the backing plate off yourself. Crank the adjuster out manually. Try to put the drum back on. Fiddle with the adjuster until you can barely get the drum on, but it turns freely once on.
Also watch the caliper while somebody applies and releases the brakes. You shouldn't be able to see much movement at all. If you can, clean up the hardware and apply Sil-Glyde to everything but the pads and rotor.
A solid low pedal can be a rear adjustment problem. If partly applying the parking brake fixes the problem, it is the rear adjustment. The self adjusters have never worked on anything I have ever owned going back to my 68 Chevelle. Pull the drums. Have them turned or grind the ridge next to the backing plate off yourself. Crank the adjuster out manually. Try to put the drum back on. Fiddle with the adjuster until you can barely get the drum on, but it turns freely once on.
Also watch the caliper while somebody applies and releases the brakes. You shouldn't be able to see much movement at all. If you can, clean up the hardware and apply Sil-Glyde to everything but the pads and rotor.