Instead of getting the cylinder replaced, I talked to 1337ssei'* dad, who said it couldn't possibly be a master brake cylinder and is instead the vacuum line folding because of heat. He said if it were the cylinder, the fluid would leak. He just so strongly believes it couldn't possibly be the cylinder and thinks it is the brake booster vacuum line. What happens when you cap that off? What would lead to such a conclusion? He didn't have time to talk about it more.

Mine didn't leak when it was failing. I don't know about the vacuum line, but it'* usually pretty firm.

That'* strange. I've never seen these seals firsthand, but is there a picture on the net that I can print out, magnify it 1000 times, and hang it behind me in poster form as I replace the cylinder so that if he comes around I can just point and not have him tell me I'm either leaking fluid externally or that my vacuum line is bad? Though outlandish, I think it would be most helpful.

This might help a little or maybe not, but there is useful info in it. Also adjust your rears and it will help make a world of difference IMO.

http://www.bonnevilleclub.com/forum/...858&highlight=

1337SSEi dad is wrong. Lack of vaccum would create a hard pedal but it would not go all the way down. There are limited numer of things that could allow the pedal to go all the way down: Mainly a brokem linkage or loss of pressure.

You don't see a leak anwhere and theres nothing broken in the linkage so that leaves the MC.and the ABS

The MC has seals around the piston shaft. When those seals leak it allows fluid from the compression side back into the resevoir which leads to the pedal hitting the floor. One item often overlooked in repairs is the shaft that goes into the MC. The end typically looks fine but press pedal to the floor to extend it fully take a look at again. If theres corrosion there then it can tear those seals up when ever the pedal goes to the floor like when you use the brake pedal to bleed the brakes. Thats why I vacuum bleed my brakes. Pressure bleeding works well too.

ABS typically works by venting excess brakine pressure on the slipping wheels back to the res. I'm not very familiar with our cars ABS system so I'll leave that to the gearheads.
I wonder if you felt the brake pedal pulsing though.

There was no pulsing, but the braking power was intermittent. The problem is that I had this braking problem shortly after swapping out the brake booster vacuum line, and 1337ssei'* dad swore it was a bad idea (I got the ricer-blue vacuum tubing, and it works really well). The thing is that the other ones work just fine, so wouldn't the thickest one hold up either the same or even better? Either way, tomorrow is my day off, and I'll replace the cylinder then. I guess it'* all the more I'll post in my work whorage post!

Which is easier to squeeze shut, the original booster line or the new line?

The new line is easier, but that'* not saying much. Both are fairly hard to squeeze.