My only problem with your statement that the front pass cyl. is bad it this: 1. We get the line to clear of mostly all the air. 2. With the amount of fluid that we have pushed through this thing, there should be at least 1 drop somewhere and there isnt at all. Why is that? You cant have a leak without leaking fluid. Lets assume that it is a bad cyl. You should get the pedal to pump up a bit if its a minor leak that wont allow fluid to escape but will allow air to enter, but not enough to prohibit you from clearing the line of air, right? Given these parameter you should feel a change in the pedal. We get nothing at all. No pump up at all. Zero. Its not like we clear the line, go to the next, clear the line, then try and pump up. We simply dont pump up at all. I can replace the cylinders, but thats just throwing another part at the problem. Just like the MC. Put a new one on, no change. Put on Dennis', no change. I dont mind eliminating problems, but not via part replacement. Something is going on here. I am thinking about getting some pipe plugs and isolating parts of the system know to narrow down our search. I figure I can plug one line at the dist block at a time and bleed/pump up the brakes. If I plug one line and the brakes pump up, bingo! Now we know where to look. Sound like a good idea or no?