Braided Brake Line failure?

[Deefer666]

[quote author=Adam2201 link=topic=4547.msg220960#msg220960 date=1452167591]
[quote author=Deefer666 link=topic=4547.msg220950#msg220950 date=1452159541]
Standard rubber brake lines don't generally fail, it can happen but more likely is that they become soft and you lose braking performance. Pulsing through the lever although normally indicates a fucked disc can be the sidewalls of the rubber lines starting to give and although difficult to explain its a different sensation of pulsing that a warped disc would give.

I have had a set of braided lines let go on me, they where fitted by a previous owner of the bike that I owned at the time and must have been twisted to get them to fit, this caused the outer braiding to split and the inner pipe to pop out like a hernia and burst. This is why I now only use the braided lines and the ends swivel to stop the twisting of the lines under installation.

Hi Deefer, how different is the feel between deteriorated lines and warped discs?  I've been getting the chattering/pulsing lever since I recently changed my pads (to EBC).  It's usually most noticeable the more pressure I apply, and backing off the brake relieves it.  The pistons moved freely when I changed the pads it and all the bolts were torqued down properly.  I changed the brake fluid this week (looked like it was long overdue) but I'm still getting the same pulsing.  There doesn't seem to be too much play in the headstock bearings from what I can tell (did the same thing I do with pushbikes, trying to move the fork backwards and forwards with the wheel off the ground).


It's hard to describe the feel, but it feels almost like the pads are chattering out of the caliper.  I've read through a few posts on here stating that new lines made a difference, and I am planning to do put some HEL ones on at some stage using the forum discount, but how would easy is it to tell if the disc is warped without a dial gauge?  I gave them a good clean last night and the front wheel spins freely with no apparent binding.  I measured the thickness when I changed the pads and the disc itself was within spec, though I will check it again.  The lines themselves look to be original though I can't see any bulging or cracking at all.  I am planning to try cleaning the floating disc bobbins at some point as well.
[/quote]

If you are planning to change the lines anyway then make that your first job, because it's a damn site cheaper than replacing discs unnecessarily!
[/quote]

Its very difficult to describe... the brakes dont feel as sharp, you have more lever travel for effectively is less grip at the caliper end. Most people never realise how much their lines have degraded unless they ride another bike as the degradation is so gradual.

I personally never use or recommend Hel or Goodridge brake lines but that's personal preference.... I normally stick to Venhill or more recently I have started to use a German TUV brand called JM and I find these are superb although not readily available outside of the trade.

The pulsing that you feel on knackered lines is more of a grabbing at the disc rather than a pulsing from the lever, again its difficult to describe but once you have experience it you will recognise it. The other thing of course to check is that the pad retention pin is in good condition and has not got grooves worn in it. This means the pad cannot smoothly travel along the pin and will grip the pad at an angle instead of square on.... this too will give a pulsing feel.

[darrsi]

It was Goodridge that I had the problem with, and I swapped them for Venhill ones.
Been fine ever since (touch wood).  :thumbup

[Deefer666]

It would be unprofessional of me to give an opinion either way about a product or company, all I tend to do is say which companies I personally wouldn't use. 

[Adam2201]

Cheers both.  Will take the pads out tonight and have a good look at the disc surface / pads/ retaining pins and clean everything up.  Otherwise will try lines then discs. Because the juddering started right after changing the pads it's leading me to think it's related, but then the braking power with the new pads is so much stronger so it could be showing up a problem that was already existing somewhere else..

[darrsi]

It would be unprofessional of me to give an opinion either way about a product or company, all I tend to do is say which companies I personally wouldn't use. 

:lol

[Deefer666]

Cheers both.  Will take the pads out tonight and have a good look at the disc surface / pads/ retaining pins and clean everything up.  Otherwise will try lines then discs. Because the juddering started right after changing the pads it's leading me to think it's related, but then the braking power with the new pads is so much stronger so it could be showing up a problem that was already existing somewhere else..

Check that your pads went into the caliper "square" & aren't snagged up on the anti rattle plate, check the pin for grooves where the loop of the pad sits, when reassembling put a smear of copperslip ON THE BACK OF THE PAD. And smear the pin with copperslip when you put it back through.

[Adam2201]

Cheers deefer.  I did find it hard to tell if the pads were seated properly in the plate on the front calipers compared to the back, but because the pin went through easily I just assumed it was ok. I don't think I put any copper grease on the front pins either, so will try that.  Looking at the price of discs, I'm hoping I can find a cheaper fix!

[Adam2201]

Hi guys, sorry if I'm hijacking the thread -feel free to tell me to foc off!  Just checked the brakes and I think I've found the source of the judder.  The retaining spring that sits on top of the pads on the left hand caliper seems to be warped  - you can rock it up and down by pushing on either end and it knocks against the caliper body.  I'm guessing it's knackered and needs replacing, but just to be sure I'm not doing something very stupid, does this look like it's seated properly?:


http://imgur.com/HWwcw65


It's the same on the right hand side, and that spring doesn't move so I'm guessing it's positioned properly and it just got bent or warped at some point in the bike's life? The pin on the left has small grooves as well, probably because the pads have juddered around so much.

[darrsi]

Hi guys, sorry if I'm hijacking the thread -feel free to tell me to foc off!  Just checked the brakes and I think I've found the source of the judder.  The retaining spring that sits on top of the pads on the left hand caliper seems to be warped  - you can rock it up and down by pushing on either end and it knocks against the caliper body.  I'm guessing it's knackered and needs replacing, but just to be sure I'm not doing something very stupid, does this look like it's seated properly?:


http://imgur.com/HWwcw65


It's the same on the right hand side, and that spring doesn't move so I'm guessing it's positioned properly and it just got bent or warped at some point in the bike's life? The pin on the left has small grooves as well, probably because the pads have juddered around so much.

You're not hijacking the thread, it was mine from September 2012.


Hard to tell anything from a photo, but there's not much that can really go wrong with the retaining spring to be honest, so i doubt it's warped?
They have little arrows on them, make sure it's positioned correctly with the arrow pointing upwards.

[Adam2201]

Yeah, the arrow is pointing forwards, and the tabs at the end of the spring are supposed to be touching the caliper body aren't they? I mean, they don't engage with the pad? I just can't understand why one side has no movement at all, but the other side clatters against the caliper when they are both fitted the same way.  I must be doing something wrong!

[darrsi]

There's not really much you can get wrong, because the pad pin can only go in one hole, and the retaining spring can only really sit with the pin guided through the curved parts of the spring.

[Adam2201]

I can't figure out how to post a video up to show you, but if you put a finger at either end of the spring you can rock it backwards and forwards against the caliper body, whereas the one on the right just doesn't move at all.  Found a few more posts on here saying the same thing about the spring (I think one is from you from when you were having problems with juddering) and talking about modding the spring so I will have a good read through those and see if I can figure it out.  Cheers for the help, I feel like I'm getting somewhere with it, as the sensation when you brake does feel like the pads are chattering about in the caliper.

[darrsi]

Shouldn't really matter if there's a bit of movement back and forth, unless it's ridiculously loose.
When you brake the motion of the wheel and the obviously the friction of the pad will only be pulling the pad forwards, there's no way the pad will go backwards at all, the force will be way too much.
It's the pad pin that takes all the weight, and that's positioned in the middle so there's bound to be movement either way when the brakes aren't being applied.


I did try that pad spring mod, and all it does is push the pads forward and keeps them in that position at all times.
The thing i found though is firstly i now know it's not necessary at all, and more importantly it was a proper struggle getting the pad pin in, it was really hard work.

[darrsi]

For the record I had a look at my pad spring this morning and it has about 6mm play in it to rock forwards or backwards, but it will always be in the forward position because that's the way the disc rotates and brakes (unless reversing obviously).
Maybe you should be looking at the spring that isn't moving at all, and make sure that one is seated properly?

[Adam2201]

Cheers for that darrsi, this is why the forum is so useful.  I'll have a look at them both again later.  The one that is "loose" has scratched the inside of the caliper, so that's what made me thing it was "wrong", but if both of yours have play then it sounds like this is the norm.

I did a really thorough clean on the discs and the juddering seems to be gone (or very reduced), so it may have been something simple like the new pads leaving a build up of material in one place (or it could have been taking them out and putting back in, greasing).  I will try a harder stop on the way home tonight to see if I can get it to do it again.  I'm going drop new pins in anyway, and will do the hoses soon so will see how it goes. 

either way, the pad and fluid change made a massive difference to the braking - I couldn't understand why everyone raved about Fazer brakes when I first got the bike!