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Corse1
24th November 2013, 08:09
My daughters little dirt bike had excellent brakes until the front line developed a hole from rubbing on the tyre. I replaced the brake line and am trying to bleed the system but to no avail. There is absolutely no pressure achievable at the lever. I realise with a new line it would take a while to bleed conventionally but have been through 4 reservoir lots of fluid so its moving down to the calliper. There is not much pressure when releasing the banjo fitting to bleed, more like a dribble which is not normal. I have never replaced a brake line before but have always bled my own brakes ok.

I have had two go's at it now and no change, what am I missing?

Thanks

jellywrestler
24th November 2013, 09:23
My daughters little dirt bike had excellent brakes until the front line developed a hole from rubbing on the tyre. I replaced the brake line and am trying to bleed the system but to no avail. There is absolutely no pressure achievable at the lever. I realise with a new line it would take a while to bleed conventionally but have been through 4 reservoir lots of fluid so its moving down to the calliper. There is not much pressure when releasing the banjo fitting to bleed, more like a dribble which is not normal. I have never replaced a brake line before but have always bled my own brakes ok.

I have had two go's at it now and no change, what am I missing?

Thanks
one of the easier ways is to remove the caliper and pads and put a spacer in between thinner than the disc and bleed it up best you can, then leave it sit for a while so any air should rise to the banjo at the top. Then check the master cyl isnt too full spread the pistons apart and that'll force feed the fluid and hopefully the air bubbles up into the master cyl, might not cure it all but at least then you should have more pressure to improve your next bleed, there's other ways too of course

Corse1
24th November 2013, 09:47
one of the easier ways is to remove the caliper and pads and put a spacer in between thinner than the disc and bleed it up best you can, then leave it sit for a while so any air should rise to the banjo at the top. Then check the master cyl isnt too full spread the pistons apart and that'll force feed the fluid and hopefully the air bubbles up into the master cyl, might not cure it all but at least then you should have more pressure to improve your next bleed, there's other ways too of course

Thank you for that. Just finished the lawns so that's the next job. That and pulling the rotors off the ST to straighten a warped disc. Its a bugger as she was having her last ride before selling as she has grown to tall for it.

Drew
24th November 2013, 09:52
I fill the system with fluid, lean the bars/bike so that it's up hill from the banjo to the reservoir inlet, and lightly pump the lever just enough to move the master piston and open the gallery. Ten minutes of that, and the system will bleed itself most of the time.

To sum up, you have an air lock at the master cylinder. Fluid can be moved through, but you'll never get pressure till it's sorted.

Corse1
24th November 2013, 10:04
I fill the system with fluid, lean the bars/bike so that it's up hill from the banjo to the reservoir inlet, and lightly pump the lever just enough to move the master piston and open the gallery. Ten minutes of that, and the system will bleed itself most of the time.

To sum up, you have an air lock at the master cylinder. Fluid can be moved through, but you'll never get pressure till it's sorted.

Yep ok that and what jellywrestler reckoned about spreading the pads to get up through the master. Both of those together and I should be good. Going outside now. Bit early to open the fridge though.

Thanks

Corse1
24th November 2013, 10:49
I fill the system with fluid, lean the bars/bike so that it's up hill from the banjo to the reservoir inlet, and lightly pump the lever just enough to move the master piston and open the gallery. Ten minutes of that, and the system will bleed itself most of the time.

To sum up, you have an air lock at the master cylinder. Fluid can be moved through, but you'll never get pressure till it's sorted.

Lean the bars to the left and 5b pumps and its rock solid. Wow that's all it was cheers for that Drew

Katman
24th November 2013, 20:12
Wow that's all it was cheers for that Drew

Stop it - you'll encourage him.

Corse1
24th November 2013, 20:22
Stop it - you'll encourage him.

Hey I got what I wanted. Why stop a good thing. Isn't that what forums are about? Oh that's right this is kiwibiker. Sorry about that. As you were Drew.