Master Cyclinder

[Stephen67]

My brakes don't really kick in till I get down to the last two inches, something I don't like. So today I opened up the master cyclinder, it looked pretty full but I filled it up all the way to the rim and let the excess run out when I put the bolt back on. This style however is new to me and I don't know if it should be doing what it did. I pressed the brake pedal down, which I could feel working in the first inch, but then the oil shot out of the top of the nut, through some pin hole about 12" high (not around but through the very top, had to be there for a reason, my reaction was very comical). I pumped it a few times and eventaully it went back to where it was. I don't know if this is a safety mechinism to keep it from having too much, or if it's not suppose to do that normally, the brakes are a little better, but not as good as when the MC was completely full. Again, these are new to me, and I don't know if this master cyclinder is specific to the '56 F-600 or anything. It suppose to do that? lol

[AXracer]

What year, type of MC are we discussing here? Sounds like you might be talking about the bleed nut used for bleeding the air out of the MC. Looks a bit like a grease fitting usually on the side of the MC. Try tightening the nut (a little more than snug, but not too tight, then fill the res. and pump the brakes. Does fluid still shoot out the fitting? Does the pedal get firm higher up when you pump it?
Or are you maybe talking about the air vent in the top of the MC cover? If it's coming out of the cover then you likely overfilled the MC, there should be a ~ 1/4" air space above the fluid when full, it is often marked with a full line. Some MC have a rubber bellows type membrane that goes on before the cover to seperate the fluid from the air above it, and it keeps fluid from coming out the vent. Be a bit careful splashing brake fluid around, it's a pretty strong solvent that will attack most paints it come in contact with in just a couple minutes.