No brake pressure

Any of them will shoot fluid up in the reservoir unless you work it very slowly.
Bled all the lines starting at right rear, then left rear, then right front, then left front?
Full stroke of a master cylinders piston causes travel over debris that has accumulated over a long period. Most times the master doesn't fail until a week or 3 after a catastrophic fluid loss and that is typically a small bypass, slowly sinking pedal.