Bleeding XBR Front Brake

[xbally]

I can't get rid of the unsmooth travel on my front brake lever.It's got a braided hose and i've tried bleeding and tying the lever back to the bars overnight to move any trapped air-all to no avail. Any suggestions would be much appreciated.

[Propellor]

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[SteveC#222]

When i bleed the system i usually push the new fluid through from the bleed nipple on the caliper UP to the reservoir.  Get a 60ml syringe and attach to the caliper with some clear plastic tube, take the lid off the reservoir PUT LOTS OF OLD RAGS/TOWELS AROUND THE BARS AND TANK!! also pull the lever back with and elastic bands. Gently push the new fluid into the system tightening the nipple up as you get near the bottom of the syringe to stop any air getting in while you refill the syringe. Keep pushing the fluid through - you may need to empty some out of the reservoir if it get full - until the new fluid comes through bubble free. Lock off the caliper nipple. check the level in the reservoir and replace the lid. With the lever free make sure you have pressure in the system and that should be it. Works for me.

[Propellor]

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[iansoady]

.....also pull the lever back with and elastic bands. .....

I don't see how this can possibly work as it will close off the hole between the piston seals and the reservoir. If it didn't, the brake wouldn't work! Otherwise, I agree it's easier from the caliper end.

I'm also very sceptical of the "tie the brake lever back overnight" method as again it effectively creates a closed system, preventing air getting out. But I know people swear by it....

[BrendanO]

Hi Isn
I find I can be lucky or unlucky with this job, and it still seems like voodoo to me! Lever held back overnight I think does put pressure on system for bubbles to rise, gentle drumming for AT LEAST 5 min (or pinging brake lever, ie letting go of it, fir 5 min) often works for me - just when you think nothing is happening, it starts belching bubbles. Or when youfinally untie lever, it releases all the bubbles that have moved up.

50ml syringe v handy, my wife got me some (pm if u need one). XBR was lucky last yr, original brake lines a bit spongy but it brakes well.

It's deffo one of those jobs where the bike can tell if you're grtting annoyed!! You have to stay calm or oretend to 

[timbo]

Cable tying the lever back overnight, has always worked for me 

[iansoady]

As a noted French philosopher might have said: "I don't care what happens in practice, the theory says no....."

If you want hard, try the coupled Guzzi brakes. I ended up buying one of those cheap vacuum pumps from ebay which sorted it out very quickly.

[Mutt]

Just a thought... is it that the pins needing a clean? I had a similar sounding issue and that was the pads not moving freely on the pins due to a bit of crud.

[Oldtimer]

Just open the bleed nipple an the weight of the fluid usually pushes the air out without operating the brake lever.

[xbally]

I've just returned from a few days holiday so will be taking on board all the above when i have a further look into this.I left the lever tied to the bars while i was away. I did notice before i went away that the previous owner who presumably put on the braided hose hadn't fully tightened up the union at the caliper end so after i tried to bleed the system at the nipple was perplexed as to why there was a small pool of brake fluid under the front wheel!

[xbally]

Seems to have fixed itself now -thanks.

[themoudie]

 

[iansoady]

I like that sort of fix. Unfortunately they often have a tendency to unfix themselves.....