Motorcycle Repair: General Motorcycle Brake Bleeding., bleeding brakes, port holes

Question
Hello Rich. I'm pulling my hair out with this. I have an old bike I'm restoring and thanks to all I've read with your "AllExperts" advice managed to get the 30 year old up and running smoothly. The brakes are the only thing left to get going. I have replaced the whole system with new components, end to end. Master cylinder, steel braid line (6 foot length), slave cylinder all brand new. Fluid is new sealed container DOT 3. I suspended the master cylinder 6 feet up on a wall and hung the slave cylinder on the ground to help with the air flow up and out the top. I flushed the system with over a liter of fluid, tapping on the line, pumped and held/open then close bleed/pump again etc. for 3 days now and all I can manage to get is spongy pressure. The 2 port holes in the master cylinder are clear and passing fluid. Help! please.
Dan


Answer
Dan, bleeding brakes can be a pain.  I use a mini-vac system and pull the fluid through the lines with some velocity so it pulls the air out with it.  If you want to try it manually, you need an extra pair of hands.  Fill up the reservoir so you don't run out.  Take a piece of clear tubing to put over the bleed valve so you can see when air is still coming out.  With the bleed valve closed, have someone pump up the brake lever to get some pressure in the line and the hold the lever in.  Then crack the bleed valve open.  You should get a little spirt of fluid out.  Repeat this until you are not getting any more air out of the system.  Tighten things up and you should have brakes.

Regards
Rich