I purchased a 1992 F-250 last month. About a week ago I topped off all the fluids (including brake). I was driving it around the day after topping off the fluids and noticed that half the brake reservoir was empty. Topped it off again and did not notice much of a leak at all (I may have done something wrong, not sure what). Parked it and found a small leak in the rear passenger side brake bleeder/cylinder/line (couldn't tell exactly). Took apart the brake and found that the drum and shoes were bad, so Installed new drums, shoes, cylinders, and spring kits in both rear tires. Started bleeding from the rear right (farthest) until no more bubbles. Went to the left and bled until no more bubbles..... decided to check the right and every time the brakes were pressed, i heard a bubbling/spitting noise (not sure exactly how to explain it) and more small bubbles came out. Went back to the left brake bled again, noticed a few bubbles, but was fine shortly after. Anyone ever have something like that happen? Or know what it might be? The brakes seem to be working ok for now though.

Sorry for the long winded question. The right side brake (problem brake) has a newer line installed. The screw that connects the line to the cylinder seems like it is not in all the way, yet it is snug (I didn't cross threads when I installed it). I'm thinking that air may be being sucked in at the screw and eventually make it through the system... maybe not?

 

The would leak fluid if it was loose enough to suck air. The end on the new line is usually longer than the original so it may look like its not in all the way. You ran the reservoir dry so it got air in the master cyl. You could try beeding it at the mc by having someone push the pedal while you loosen the line at the mc, let the pedal go all the way down and let the fluid stop running, then tighten the line. Repeat that a couple times then bleed it back at the rear wheels and I think you'll be fine.

 

Sounds good. Thanks.