Front brake master cylinder question

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Jan 13, 2013 | 10:07 PM

tonycap

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Joined: Mar 2008

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Front brake master cylinder question

I have replaced the front brake master cylinder and hand control on my bike but I cannot get any fluid to flow through it..I put brake fluid in the reservoir and even with no brake line attached I pump the hand brake and nothing..no fluid.
Its a brand new unit so I am not sure what the problem could be....maybe the unit is faulty?

Any suggestions?

Jan 13, 2013 | 10:13 PM

Joker's back

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Joined: May 2011

Posts: 302

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From: Denham Springs, LA

There may be a small plastic shipping plug in the hole the banjo bolt screws into. The stroke of the lever does not move alot of fluid to operate the piston in the caliper. It takes awhile to build the flow and will take longer to fill the line and bleed to pressure.

Pumppumppumppumppumppumppumppumppump.....

Jan 13, 2013 | 10:45 PM

Spanners39

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Joined: Dec 2010

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From: Coromandel Peninsula New Zealand

Undo the bleed nipple at the caliper and use a syringe (full of brake fluid) and piece of tubing to bleed it backwards, from the bottom.....works every time!

Jan 13, 2013 | 11:42 PM

tonycap

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Joined: Mar 2008

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Thanks for the reply guys.
What I did after I put the post up is I removed the master cylinder off the handlebars and filled the banjo outlet hole with brake fluid then attached the banjo bolt and I did get some fluid flowing. What happens now is that when I attach a vacuum pump to the bleed nipple and pump I get a lot of bubbles at the master cylinder. I get a little fluid coming out of the nipple sometimes but I still cant get a continuous flow of fluid.
I will try the syringe method spanner39 suggested and see what happens.