Soft lever after fitting braided lines.

[doofus4000]

I replaced my standard brake lines with a braided set of hels the other day. My reason for doing this was due to having a soft lever. I could almost pull the lever back to the bar under full braking and no braking at all at half lever. I have fully bled the front brake and I am still getting this type of brake feeling, from friends bikes I'm pretty sure my lever shouldn't feel like this. Anyone any ideas what's going on?

[yorkie_chris]

Not bled properly, or caliper dust seals dragging pistons back in.

[doofus4000]

Not bled properly, or caliper dust seals dragging pistons back in.

Has to be no2 because there sure as ain't any air in there, I've bled half a bottle of brake fluid through the front! How do I fix the seals?

[yorkie_chris]

I see it a couple of times with people "I've bled 450 litres of fluid through and it's still spongy! I'm sweating the stuff through my pores and a load of hippies keep coming round and washing it out of my dog!"

It is completely possible to bleed loads of fluid through and miss the odd bubble. Make sure you bleed it out of all the banjos especially with the stock splitter thing. And make sure you angle the master cylinder to get any bubbles out of that (worse on S model).


Search on here for caliper rebuild. Basically... take pistons and seals out... clean sh*t out... lubricate, reassemble, rebuild.

[doofus4000]

The stock splitter thing you refer to, I can still only bleed out of the left and right caliber bleed nipples yea? How much more can you bleed for until you realise you are getting nowhere? That's what it seems like to me at the mo and its more the seals thing you mentioned.

[yorkie_chris]

No, bleed it out of the banjo fittings.


You know it's not working when you aren't getting bubbles out and bleeding more out (from that point) isn't making matters any better.

[doofus4000]

Ok so crack open the banjo bolts a little and bleed from them instead of the bleed nipples? So there will probably be fluid dripping out of them when I open each time.

[yorkie_chris]

Yes

[doofus4000]

Ok thanks will give it a go.

[pilothaz]

Another thing to try is once you have completed the bleed, zip tie your brake lever to the handlebar for the night. This will ensure that it stiffens up. I didn't need to do this on mine but did anyways. Was great stiffness once I released the zip ties.

Sent from my SGH-I747 using Tapatalk 2

[doofus4000]

Another thing to try is once you have completed the bleed, zip tie your brake lever to the handlebar for the night. This will ensure that it stiffens up. I didn't need to do this on mine but did anyways. Was great stiffness once I released the zip ties.

Sent from my SGH-I747 using Tapatalk 2

Ok so just zip tying it will stiffen it up a bit too? Will try that, thanks!

[johnnyrod]

By "soft" do you mean it's never really firm, or too much travel then it goes hard. If it's the former then it could be the master cylinder seals, or air still trapped. If it's the latter then it's most likely the pistons pulling back in like YC says.

For my 2p on bleeding, you may have some air trapped at the top banjo (master cylinder connection) as Chris again suggests. If you can stand it overnight so that the banjo is at the lowest part i.e. rest of the master cylinder/bar pointing uphill, it'll come out by itself (doesn't make any odds if you tie the lever or not as long as you untie it before cahnging the angle again). In a similar way, whenyou're bleeding the calipers, make sure the nipple is a the highest point by angling the steering as required. Finally, sometimes you get small bubbles from all the fluid whooshing around, these take a bit of time to settle as they travel slower than big bubbles, so give it a few days and bleed a few ml out which should bring the last few bubbles with it, if any.

[doofus4000]

By "soft" do you mean it's never really firm, or too much travel then it goes hard. If it's the former then it could be the master cylinder seals, or air still trapped. If it's the latter then it's most likely the pistons pulling back in like YC says.

For my 2p on bleeding, you may have some air trapped at the top banjo (master cylinder connection) as Chris again suggests. If you can stand it overnight so that the banjo is at the lowest part i.e. rest of the master cylinder/bar pointing uphill, it'll come out by itself (doesn't make any odds if you tie the lever or not as long as you untie it before cahnging the angle again). In a similar way, whenyou're bleeding the calipers, make sure the nipple is a the highest point by angling the steering as required. Finally, sometimes you get small bubbles from all the fluid whooshing around, these take a bit of time to settle as they travel slower than big bubbles, so give it a few days and bleed a few ml out which should bring the last few bubbles with it, if any.

The latter Jonny, nothing then the lever gets hard like it should near the end of its stroke. I will try bleeding as per your procedure above and see does it reep any results. Thanks

[yorkie_chris]

If it is nothing then it goes hard then it's likely the seals.

[johnnyrod]

Sounds like the bleeding won't help but give it a go. The loose bit of the lever travel is just pushing the pads up to the discs. If that's the case you need to clean the calipers, mainly the grooves the seals sit in, scrupulously. What's happening otherwise is that the seals twist a bit as the pistons move, and when you release the lever they pull the pistons back too far into the calipers.

PS YC posted at the same time!

[NTECUK]

Caliper re ferb time.You know it deserves it