nc30 brake bleeding problem

nc30chris · Post by **nc30chris** » Sun Mar 17, 2013 3:41 pm

im in need of some advice, im currently restoring my 1992 nc30, ive got to the point where im refitting the front of the bike back together, ive stripped the calipers, new seals etc and am now fitting some new braided lines. but i have a problem, i cant bleed them, i cant even seem to pump any fluid by using the brake lever, eventually gravity pulls fluid down the lines and if i crack off the unions at the calipers, fluid will come out. but i have absolutley no pressure at the top end the lever can be pulled easily as if no lines were connected, ive got no leaks and everything is fitted correctly, ive tried all the usual bleeding procedures but nothing works. i suspect the master cylinder may be knackered, but the only doubt in my mind is that the front brakes were working fine before i stripped it down. any advice would be really helpful.
thanks in advance
chris

Post by **jetblack** » Sun Mar 17, 2013 3:58 pm

Have you bled the master cylinder?

nc30chris · Post by **nc30chris** » Sun Mar 17, 2013 4:05 pm

no i havent, how do i do it?

Post by **jetblack** » Sun Mar 17, 2013 4:37 pm

You need to loosen off the bolt through the brake lines on top of the Master cylinder as you squeeze the lever then nip it up at the end of the stroke. Repeat about 100 times :-) it should help pull fluid through from the reservoir as any air is expelled. It gets trapped up the top there.

nc30chris · Post by **nc30chris** » Sun Mar 17, 2013 4:50 pm

!aah, i see, ill give it a go and let you know how i get on, thanks!

Post by **jetblack** » Sun Mar 17, 2013 4:57 pm

Make sure you nip up before releasing the lever or you'll just suck more air in. And use a rag to stop spillage! good luck.

Post by **Delboy** » Sun Mar 17, 2013 4:58 pm

Several options...tie brake lever back, open bleed nipples let gravity take its toll....reverse bleed using a syringe....get some aquarium pipe and put one end on the nipple and the other end in a jar with a drop of brake fluid and pump like a porn star...or all of the above.
If you wernt so far I'd sort it for you, I've done a few now just keep at it and you will get there

Post by **V4beermonster** » Sun Mar 17, 2013 6:10 pm

Another trick is to put your bleed pipe on the nipple and attach a syring pull open the syring then the nipple this creates a vacuum and pull the air lock out always work for me

nc30chris · Post by **nc30chris** » Sun Mar 17, 2013 7:01 pm

thanks for the advice guys, pleased to say that after several bleeds top and bottom, ive got something what feels like a brake! a few more bleeds and it will be spot on! id of never managed without your help! sadly i ran out of time today to get it 100% but there is light at the end of the tunnel! thanks again.

Post by **jetblack** » Sun Mar 17, 2013 7:20 pm

Tie the lever back with a tie wrap until you get back to finishing the job.

nc30 brake bleeding problem

nc30 brake bleeding problem

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