Hey all.. I am going to flush the brake fluid tonight and will try and use cummuters technique.. However my question is.. if there is air in the line we didn't realize.. how will we tell and will we know immdeiatly or maybe hours into a ride?  Also will air cause the brake just not to compress or will it cause it to lock up?  Stupid questions I am sure but going to Laguna Seca this weeked for Moto GP!   Thanks

Hopefully, I'll see you there!  Bob Broussard is going, too!
http://gstwins.com/gsboard/index.php?topic=28473.0

What is the commuter's technique?  I've never heard of that before.  Are you using a Mityvac?

As far as feeling, it might be easy, or it wont be for hours into the ride.  If there is air in the lines (or in the caliper body), it will have a spongy feel.  Be sure to pump up the brakes after the bleed; if they don't pump up, then you have air (or, you left the bleeder valve open).

Heat will cause the air to expand and that may cause a lock-up, or binding, of the brakes.  This happened to an aquaintance of mine, on his Ducati.  It is uncommon, and usually you need a very large air pocket to begin with, and the rotors to rub constantly, creating heat.

Typically ... air in the line will gravity itself to the top ... Bleed the banjo at the master cyl, the bleed screw at the caliper and the banjo at the caliper and you should be all set ... the biggest caveat is ... it will gravity itself, if its got some decent persuation ... aka riding it down a bumpy road ... whihc of course is a likely nightmare without decent brakes ...
Cool.
Srinath.

Cool Scratch.. I will be at bike night(s)..  I have the black airtech body kit on it.. All body work is black however the tank is silver and black...  We are riding up the coast from LA tomarrow and heading back on Monday.. would be cool to run into eachother! (on foot that is)

Generally, if there is air in your brake line, you'll know right away.  The brake lever will sqeeze all the back with very little resistance and you won't do much stopping if there is any amount of air in there.  If you're not sure, take it for a spin around the block, if you get the piss scared out of you when you try to stop, you need to bleed your brakes some more.

Don't worry about wasting the brake fluid, you can't save it anyway, so just bleed more through than you think you need to just to be safe.

Also here is cummuterguy's recommondation if you are interested

"Flushing with dot4 is a good idea, it's quite easy to do.

quick easy way  to do it.

1. unscrew your master cyl cap (clean it first so as not to get grime or dust into the cylinder)

2. using some type of suction tool, (turkey baster or even that blue 'snot sucker' they have for infants will work) remove as much of the old fluid in there as you can.

3. refill the cylinder with new fluid, leave the cap off for now.

4. with your bottle of fluid right there with you, open the bleed valve on your caliper, if you have some tubing to allow the fluid to flow into a jar,great use it to keep your floor clean, but if not,it's water soluable.
DON'T PUMP THE HANDLE!!  gravity will let the fluid flow out without air coming back into the system. DON'T WALK AWAY OR GET DISTRACTED WHILE YOU FLUID IS DRAINING!  if your master goes empty, you'll have to bleed the whole system.

5. watch the level very closely in the master, top it off often, before it gets more than 3/4 empty, but let it drain at least 3 times the amount that would normally be in the system.

6. close the bleeder valve, top off the level one last time in the master, and re-install the cap.

7. you're done, clean up any spills quickly, brake fluid eats paint!!"

it would take like 2 hours to drain the old fluid and do the job if you don't pump the brakes.  It's extremely easy to bleed the lines; not like an automobile where you have to coordinate with a partner. 

Just open the reservoir cap, suck out most of the old fluid (not all of it, you don't want to let air into the passage) and refill.  Crack the bleeder screw, squeeze the lever, close the bleeder screw, release the lever.  Repeat until new clean fluid is coming out of the bleeder screw and no air bubbles are visible in the drain hose.  Kerry posted a good walkthrough around here somewhere, try searching for it.

-M