Front brake line replacement ***fixed***

8 replies to this topic
  • 426_Texan

Posted April 16, 2004 - 06:26 AM


After installing a new brake line, whats the best method to getting started on the bleeding process?

Is there any way to "prime" the line? Or do I just refill the master cylinder and start pumping? :)

  • Yamahopper

Posted April 16, 2004 - 06:51 AM


When I did mine, I used a hand operated vacuum pump on the bleeder screw and sucked fluid down the line. You can rent these at Autozone for almost nothing. You'll need to put some telflon tape around the bleeder screw so that the pump won't just suck air in around the screw threads. Then just do a couple of standard air bleeds and then do the ziptie around the lever overnight trick, and you'll be all set.


  • 426_Texan

Posted April 16, 2004 - 09:08 AM


Hmm...only a few tiny air bubbles now, but absolutely NO pressure. Now what? :)

  • beezer

Posted April 16, 2004 - 09:50 AM


Keep at it, at dirt bikes master cylinder dosn't move much fluid with each lever pull. Some bikes are very hard to get all the air out.

When you are done tie wrap the front brake lever against the bar and leave it over night. The lever should be much firmer.

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  • Fly-nBri

Posted April 16, 2004 - 10:24 AM


Make sure you tap the caliper with something like a small hammer to get some of the air that might be trapped in there. I tried it and it really works. :)

  • Yamahopper

Posted April 16, 2004 - 10:51 AM


The vacuum pump really helps to get the flulid through the whole system. Alternatively, if you just leave the bleeder screw loose and put a hose on the end and put it into a jar or coffee can, it will eventually (might take an hour or so)start to drip out due to gravity feed. At that point, you should be able to do the regular brake bleed drill...

  • RCannon

Posted April 16, 2004 - 10:58 AM


I have had much better luck replacing the lines if I wait a bit before the lower fitting is tightened.

I will fill the master cylinder, let it finally drip out of the line in the lower section, then button it all up for final bleeding.

This whole process is a pain in the butt. Beer is a great mental help.

  • 426_Texan

Posted April 16, 2004 - 11:23 AM


I'm getting plenty of fluid out of the bleeder with very few to no bubbles. I have a clear hose connected to the bleeder to I can see the fluid/air that comes out well. I just have no pressure at all yet and it's freaking me out :)

Also, when I pump the lever with the cap off, its blowing bubbles inside the reservior. Is this normal or does my master cylinder need a rebuild?

  • 426_Texan

Posted April 16, 2004 - 02:36 PM


I gave up for time being on the brakes,and moved on to a new spark plug and mixture screw for the carb.

Ran it up the street and back, now I'm getting some pressure in the line. :usa:

Guess the old girl just wanted out for a gallop, now she's cooperating with me on the brake bleeding :D

:D :D :usa: :D :)

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