Front brake bleed issue

[Yamazer-92]

Got my calipers back today after having them refurbed with new seals etc, went to re fit them to the bike with new hel braided lines and there is a big problem. We can get fluid to the calipers, then the fluid coming out into the bleed nipple and pipe is nice and clean no air but there is absolutely no pressure whatsoever at the lever. This is so frustrating because it was the very last job I am doing on my fazer rebuild since my accident, this was meant to be the last easy piece in the puzzle.


My Dad fitted the brake lines, he put the yellow label at the top and the black rubber bit at the caliper end is this correct? Just ruling out anything strange we may have missed. We have tried priming them, bleeding them manually and also used a vacuum and it is all resulting in fluid entering calipers with minimal air bubbles or completely clean but absolutely no pressure at the lever. The fluid is not leaving the reservoir very quickly either. I am now thinking the master cylinder has somehow had it? Any help would be massively appreciated!

[His Dudeness]

try pulling the lever a few times and then crack open the banjo bolts as you hold in the lever. start at the m/c and work down

[JoeRock]

As above, sounds like you've got a load of air in the master cylinder. Very slightly crack the banjo (with rags underneath to catch the fluid), and slowly squeeze the lever in. Soon as fluid comes out, nip it back up!

[red98]

hi yamazer....ummmm,might be air still in the system,trapped at the top parhaps.......you could try reverse bleeding. ....get yourself a pump action oil can....nice clean one....and a snug fitting length of tubing,fit the tubing to the spout of the oil can and the other end to the nipple on the caliper,release nipple,take top off master cylinder,fill oil can with break fluid and use the oil can to pump the fluid from nipple to mastercylinder...not with the brake lever on the bike...open and close the nipple as you would using conventional method,keeping an eye on the level in the master cylinder,this method has never failed for me,your pushing the air the way it wants to go , to the highest point,not fighting against the laws of mr isaac newton 
 
if this dos`nt work i would look at master cylinder , parhaps replacing the rubbers....good luck and as always let us know how you get on .

[Yamazer-92]

Well we tried cracking off the banjo bolts and nothing is working, like I say fluid is coming out into the bleed pipe and it has minimal / no air but the lever has no pressure at all. The master cylinder is creating pressure, my dad covered the hole with his finger while I pumped the lever and there was definite pressure. This is doing our heads in, somehow fluid has managed to leak onto the mudguard and a tiny bit on the wheel too and taken away some paint just to add to the misery. I don't know where to get a syringe or oil can or whatever to back bleed, we are going to completely free up the brake lines and hang up the calipers as high as we can above the master cylinder and leave it overnight. I just honestly don't see what we're doing wrong, was meant to be the first ride on the bike today and we had a decent route planned but its just sat there like a sack of shit as usual going nowhere...

[fazersharp]

Syringes can be bought off ebay, the 50mm has a tapered nose and you can push on a variety of different size tubes because of it 

[red98]

Try a petshop for the syringe...they are used for medicines for our furry friends........you mentioned you have good pressure at master cylinder banjo, have you done the same test on the banjo on the calipers ?......

[Flak]

I normally get syringes from the chemist (pharmacy counter).

[Yamazer-92]

Red is this what you meant by pump action oil can, because I can go and get one of these immediately if so and give it a go
http://www.halfords.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&productId=987619_en_gb&catalogId=10151

[red98]

Yes...thats the type...but you need one with a metal rigid spout so you can push the rubber tube on for an air tight seal, not the flexi tube thats on this one.

[red98]

just found mine...shame your not a bit closer 

[RobG UK]

Or you can try the old fashioned trick.

Pull the lever in, tie it to the bar and leave it overnight.  Sometimes works.

[His Dudeness]

you could try hanging the caliper above the m/c over night as well

[JoeRock]

Did you use aftermarket seals, or proper Yam ones?

[JoeRock]

Wait, something even more obvious - have the pistons actually come out of their recesses? If they've been pushed all the way home it will be a bit of a bastard to get them out - you'll basically have to bleed the system, and then sit there and just squeeze the lever until fluid goes under the pistons and pushes them out and you'll actually get resistance?

[Yamazer-92]

Hi guys, this was all sorted yesterday afternoon thanks to red's idea of the oil can back bleed! Worked an absolute treat, lever is solid as a rock just like before and we tied it overnight and bled this evening to get rid of any residual stuff. Nice solid front and rear brake now, my bike is officially rideable again and now looks more like how I always wanted it to. Just a couple more pieces and it will be finished! Pics to follow soon. Thanks very much again for all the help, this forum is excellent.

[Yamazer-92]

Oh yeah and Joerock they are all OEM seals and the pistons did come out a little when we were having trouble yes, I think it was just a massive air lock somewhere causing problems

[red98]

Glad you got it sorted yamazer.......the oil can tip is an old one, ive never known it to fail....your right about the forum,lots of help if you ignor the pi**take  ...........got any pics yet