My son's '79 lost its brakes yesterday, and we spent today fighting
this: I can't get all the air out of the left-front line. We've run
8-10 ounces of fluid through the system, which is maybe 18 inches long
on this wheel, and still there are bubbles with no end in sight. The
system must be sucking air somewhere. There aren't any obvious fluid
leaks, the flexible lines are intact, but we cleaned the entire master
cylinder area and plan to look closer tomorrow---We made a bit of a
fluid mess while replacing a line on the rear, which is where we
thought the problem was.

The other symptom is that the pedal is firm if we hold it hard, but a
soft push goes to the floor.

Last, the master cylinder reservoir squirts up if we hit the pedal
hard...is that normal? (this is why we made the fluid mess)

We rebuilt the rear brakes in the spring, including new cylinders and
one new line in back, and replaced the front pads a couple months ago,
flushing the entire fluid system. It's been working fine since. No way
am I an expert or even very experienced at this, but I'm pretty
confident we're doing the bleed properly. What should I do next?

-John O