Topic: New brake master question

[Bootlegger56]

I don't know if its a factor in this case or not but I rebuilt the master on my K1 and also had to tap out and replace the bleeder in the caliper with one of these two part bleeders that consists of a threaded fitting that goes into the caliper and another threaded bleeder inside of that fitting.  I could not get mine to fully bleed either using a one man bleeder, taping the lever open over night, pumping until I got carpal tunnel syndrome and praying to the brake gods.  I finally figured out that it was getting air back in around the threads of the threaded bleeder portion.  I pulled it out and put a wrap of Teflon tape around the threads and bled the whole thing in just a few minutes with a one man bleeder. 

[LesterPiglet]

Bodi: "Explain to me how pressurizing the brake hydraulic system and closing the only return hole to the reservoir for several hours will help get air bubbles out."

Your theory of the taping the lever back not working may be sound but conflicts with my experience. I'm sorry I can't write a paper on it.

[dave500]

so it follows to not bleed the brake but to just hold it back with a rubber band and wait?

[LesterPiglet]

No Dave, it's a last resort.
I might try your suggestion and see what the outcome is, when I have a spare week or two.

[dave500]

yeah just bleed them normally,if you encounter something odd try it,new hoses help even if they arent super duper stainless braided ones,old hoses trap air in their porousness?

[PeWe]

I had no problem with new SS braided brake fluid lines, all the way down to the caliper. Ok level with fluid in the reservoir, pumped the lever a few strokes, kept it in, opened the bleeder valve on caliper. Closed it and pumped again kept it in,opened the bleeder valve on which I had a clear tube on so the old brake fluid with bubbles ended in a jar. Repeated this and refilled fluid level until the fluid coming out thru the caliper bleed valve looked new.
My brake lever had not been in use for 25 years so it leaked a little bit in the beginning. OK later on.  I hope it will withstand real use in higher speed as well.

-Is it possible to refill from bottom with a big syringe connected to the open bleeder valve and pump so the bubbles can evacuate upwards?

[trueblue]

"Guess it didnt work for them either?"

Worked as well as lighting some incense and dancing naked would have. Old wives aren't the only ones with tales.

Explain to me how pressurizing the brake hydraulic system and closing the only return hole to the reservoir for several hours will help get air bubbles out.

Very simple, when you sit there pumping the lever the fluid gets pushed down the line.  It takes with it the air bubbles, when you release the lever the air bubbles move back to their original position.  When you tie the lever back, the air bubbles have the chance to work their way back up the line.  Because they are compressed they will take much longer to rise hence leaving it overnight.  When you release the lever the first thing it does is let the fluid back into the reservior, and takes with it the air that has collected there over the previous hours.  You can't tell me it doesn't work I have used this trick on a number of bikes and several cars and it has worked on all but a couple of the cars

[Stev-o]

-Is it possible to refill from bottom with a big syringe connected to the open bleeder valve and pump so the bubbles can evacuate upwards?

Yes, with the power bleeder I wrote about earlier in the thread....

http://www.ebay.com/itm/Reverse-Pressure-Brake-Clutch-Bleeder-/271426486191?pt=Motors_Aviation_Parts_Gear&hash=item3f32477faf