NC30 Bleeding Front Brakes

[Stlleg]

Hi,

I know nothing about bikes and I'm having trouble bleeding the front brakes of my NC30. I have bleeded the rear brakes no problem (using a rubber tube into a jar of fluid) without any problems.

When I have tried the same on the front brakes (after opening the reservoir) I have lost all pressure in the brake lever and when I'm pulling it no fluid is coming out of the bleed valve. I've tried pulling the lever, then closing the bleed vale while it is pulled in and repeating etc but nothing seems to work.

Any advice would be appreciated.

Cheers

[speedy231278]

If the front brakes are in the right mood, it can be a total bastard. I've done the fronts loads of times, without any issues whatsoever, taking just a few minutes from the system being opened to it being fully bled. Then, last time, it went all horribly annoying and took several hours! It seems the master cylinder can be very hard to prime, and if it won't suck in any fluid, you get nowhere in a hurry. Some people use vacuum bleeders. I'm not sure of the exact technique, but the principle is that you connect a gadget to the bleed nipple and literally suck fluid down to the calipers. My normal method is to attach aquarium air hose to both bleed nipples, and run it back to the m/c reservoir. Then keep it topped up while you pump the level. when bubbles stop coming back up through the hose, you know it's done.

[GeeTee]

Air lock in master cylinder. I crack the top fitting to hose to push air out there, catching any fluid in a rag and bleed through once I have pressure at lever

[VtypeV4]

Mine were a nightmare when I did them last week, seeemed to take forever to get anywhere then they came up good.. I think I experienced the 'air lock in the master cylinder' syndrome..

[SmallFrowne]

I've done mine by pumping some fluid in with the lever to start with then using a syringe and a bit of hose on the bleed nipple to "suck" the fluid through.