Brake System Fill and Bleed
The O-ring was sitting on top of the inlet port, instead of around the indentation in the middle of the inlet port body. Because the plastic adapter is constrained with a circular clamp, having the O-ring at the top of the body does nothing at all. As I recall, these plastic adapters were already installed on the master cylinders when they arrived in the kit, and I had left them in place assuming they were installed correctly. I was wrong!
Once I did that, the MC leaks magically stopped. Next, I worked my way around to each caliper, attached a nylon hose to the bleed valve with the other end submerged in some brake fluid in a plastic bottle, and pumped the brakes until I got flow. I didn’t worry about air bubbles at this point – I just wanted to get the system basically filled. My tiny reservoirs made this process a little tedious. They empty out in just four pumps of the brake pedal, so I had to constantly refill to make sure I didn’t air-lock the master cylinders. Anyway, this process went reasonably well, and I soon had filled brake lines.
To my surprise, I had only one leak (from the rear T-junction), which I easily fixed by tightening the compression nut. Honestly, with all the bending and flaring, and fitting and refitting, etc., I expected much worse.
With my system now filled and leak-free, I did the final bleed process. Because I was working alone, I followed this technique:
https://www.youtube.com/watch?v=oi4BnNA3Ep4. Basically, as I bled each brake, I ran a length of clear nylon tubing from the bleeder into the reservoir. Doing that from the rear brakes required several feet of tubing. Then I just pumped the brakes repeatedly until there were no more air bubbles. This method is especially good for very small reservoirs like mine. Instead of having to constantly worry about the reservoir running dry, the fluid just recirculates from the brake to the reservoir, and you can pump the brakes as much as you want until you are convinced there is no air in the system.
After that, my brakes were firm and felt great – no sponginess whatsoever. I confirmed by hand that they are stopping the rotors. So, for now, it looks like I have brakes!