The International CBX Owners Association

When you Mityvac at caliper bleed nipple, do you have to have the brake lever partially applied? or can you leave it in the un-applied position?

I leave it in the un-applied position.

You must also thread tape the bleeder threads or you'll suck more air than fluid. But be aware that there is no magic with the Mity Vac on the CBX front brakes. They are quite problematic to bleed.

Dave

Problematic due to the splitter on the lower tree, holding air. With a helper, you could crack one of those fittings to bleed off air, there.
Or, bleed the brakes with the bike on the side stand, putting the splitter at an angle to let the air escape with the lever held against the grip with a rubber band, overnight.
Or,
You won't have that problem if you go to, 2 separate lines from the master or one line down to the right caliper, double-up and jump to the left. Eliminating the splitter altogether.

And if you don’t have a helper, cut a 2 inch wide section from an old bike tire tube, use it on the bar and brake lever to hold pressure on the system while you mightyvac the calipers or bleed the splitter, just watch the lever, once it hits the bar, pump the lever back up and away from the bar, rinse and repeat. You can use this same wide rubber band to hold pressure in the system overnight, then tap the splitter and calipers with a rubber mallet to get any air bubbles to travel downward towards the calipers when you bleed the system.

OR buy an inexpensive pressure brake bleeding kit that forces the fluid down the brake system from the m/c to the calipers, like this for $125 from Summit.

https://www.summitracing.com/parts/mvp-0250

OR, be a tight wad and buy a new metal oil can at the hardware store, fill it with brake fluid, and fill the system through the nipple at the caliper, pushing the air up through the system. Use the rubber band trick, a piece of wire, or whatever to hold the master open to expose the return port.

Excellent, Rick. One suggestion: rinse that new oil can with acetone first to get any preservative oil off the inside.