Re: CB350 'Sly'... font brake and rolling chassis
I didn't see that you got your brake MC issues resolved. I might have some useful input. I had an modern motocross bike that had the worst MC to bleed. I used to get very very frustrated and give up. I eventually figured it out and haven't had a stubborn MC since.
I'm not sure w/ your other ones if you were building some pressure or none at all. I just put a MC from a motocross bike on my 360 (same caliper) and it works just fine w/ a 5/16 MC (comes out to like 8mm). It honestly could be a little stiffer, but it feels no diff. than the same one that was on my moto bike, and raced w/ that every weekend.
It sounds like your were getting nothing at all. In that case, you might want to try this.
Sometimes there is a little bubble that will form right inside the MC at the end of the banjo bolt. It it is big enough that the fluid will move around the bubble before the bubble will bleed out. You have to start by filling the entire system with fluid, which ever way you choose. If you crack the bleeder screw at the caliper, and remove the cap from the reservoir, you should get some fluid flowing freely through the bleeder. It won't be much, but enough that you know it's moving. That will verify that you have fluid all the way through the line to the caliper.
At this point I do a couple of bleed reps. Pump, pump, crack the bleeder and hold the lever, close the bleeder. Now you have to bleed the brakes @ the MC, through the banjo bolt. The key to this is to position your bars and the MC in whatever way you can to get the banjo bolt angled upward. If it is angled downward, the bubble will follow gravity upward, and just sit in there.
So, now pump the lever a few times, hold it, and crack the UPPER BANJO BOLT, then close it, and release the lever. Just like you would do, if you were cracking the bleeder screw. I will bleed at the banjo bolt once or twice, then bleed it at the caliper once or twice. By that point you should be building pressure.
I know this sounds odd, but I have had those stubborn MC's that I've tried everything on. This is always the trick up my sleeve, works every time.