A quick, easy check for air,, after you're sure the rear brakes are adjusted properly,, is ,.. with m/c cap on,, have friend pump 2 or 3 times and hold down,,, remove the cap,, have the pedal released as you watch the fluid levels,... any "geyser" ( fluid spouting well above the surface) is compressed air, "springing" fluid back,, front or rear,, and that system needs more bleeding..
-with the exception that,- if the rear brakes are outta adjustment,, the return springs can cause a fluid return from the rears..
setting the emergency can help if you can't adjust the rears..
brake fluid is excellent paint remover,, so don't splash any on your paint.. immed rinse with water if you do..
hope it helps... grant
