Main Motorcycle: 2005 Bonneville Blue 790
Join Date: Sep 2006
Location: Central Maryland, USA
Other Motorcycle: 1973 CB450, long gone
You can try this: Get the reservoir off its mount and have a helper hold it and watch it. Lower the fluid level in the reservoir to near the bottom and put the lid on loosely so it's covered but vented. Gently push the brake pistons in to force fluid up the line into the reservoir. If you're lucky, any stuck air will go up with it. Some tapping on the caliper might help and won't hurt.
Remember that air wants to go up, so it's best to push as much of it as possible up the brake line before you start pulling it out at the caliper end. Keep the caliper unmounted so you can position it to your best advantage.
You can use a syringe with tubing to push brake fluid into the caliper.
I do the above before I start bleeding with the Mity-Vac, so I start with a system which hopefully doesn't have too much air, because it is indeed tedious to get it all out.
When bleeding with the Mity-Vac, have a helper watch the fluid level and add fluid to ensure that no air gets in at that end, or you're wasting your time and brake fluid.
It's a messy process for us amateurs, but you will eventually get the air out, and the Mity-Vac is the easiest way to do it. Once you've done it once or twice, you'll have a better feel for how to go about it.
Finally, about the light. Yes, it's a pressure switch in the banjo bolt. Don't worry about it until you get the brake working. No pressure > no light. They are known to go bad and get stuck in the on position--dangerous--but you have no way of knowing that until you have a working brake. If it ever does get stuck on, disconnect it; your front brake light switch will take care of things until you replace it.
2005 Bonneville Blue 790cc, AI removed, Staintunes RC, no snorkel, inlet enlarged, 118/40/NBZT needles/1 shim/3 turns, Ikon 7610s, Ricor Intiminators, Barnett green clutch springs, Michelin Pilot Activs, D9 gauge panel, tachometer.
Last edited by Baltobonneville; 09-09-2019 at 10:15 AM.