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Braking suddenly gone bad


Guest raabey
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So when I was on a rideout with Phil and Joe, I noticed the braking performance decrease...


I.e. I had to pull the lever alot further in before it started to brake. It seemed to suddenly happen when on this quick ride, wondering if it's caused by heavy braking.


My pads have enough wear left, nothing seems to be leaking either.


I'm going to flush out my fluid and bleed them this weekend. Otherwise, is there anything it could be?


Thanks.


Edit: I've read it could be brake fade - due to high heat. Maybe explains due to the fact I was braking hard at high speeds. Then again I'd assume that EBC Dot 4 brake fluid could cope with high heat.

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I told you homes... you need to bleed the braking system starting from the master cylinder. Then pop new fluid in with no air. I'm putting £100 on that sorting it out ;)

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I told you homes... you need to bleed the braking system starting from the master cylinder. Then pop new fluid in with no air. I'm putting £100 on that sorting it out ;)

 

Yeah home boy I'm thinking that'll work!


But the cause is what I'm wondering! Brake fluid overheating and breaking down?


Get back to work you douche!!

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I told you homes... you need to bleed the braking system starting from the master cylinder. Then pop new fluid in with no air. I'm putting £100 on that sorting it out ;)

 

Yeah home boy I'm thinking that'll work!


But the cause is what I'm wondering! Brake fluid overheating and breaking down?


Get back to work you douche!!

The cause is; you had air in the system which leads to moisture build up and the brake fluid not being able to operate as it should.


Carry on with your lip sunshine and I'll make you buy me another diet coke.

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When the fluid boils you don't get a little fade it just goes and there is nothing!!


It's scary shit when you experience it!


I would do a fluid change first as it's easy and cheap


Also check to make sure your pads or discs aren't contaminated

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Also check to make sure your pads or discs aren't contaminated

 

You mean contaminated with brake fluid?

 

Carry on with your lip sunshine and I'll make you buy me another diet coke.

 

Piss off fat boy you think you know everything ;)

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Now you've just bought yourself a ticket to doing it yourself... offer withdrawn :up:

 

What you on about biglad I'm doing it in Yorkshire anyway :up:

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Also check to make sure your pads or discs aren't contaminated

 

You mean contaminated with brake fluid?

 


with anything!


also check your fork seals make sure you dont have a leak


give everything a good going over with some brake cleaner too


if these dont help I would be looking at stripping the calipers for a rebuild and new pads and possibly new master cylinder seal kit

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We were breaking pretty hard, I can see from my camera footage i was bottoming out my forks on some occasions (I'm tweaking my suspension settings to avoid it again - thats another story) and you were keeping up with us pretty well, so your brakes did get a good workout.


We didn't see any leaks but the lever felt very spongy, and the fluid level was low. I reckon you might just have got some bubbles in the old fluid, so bleed them out and it will go away :)

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Right... I'm stumped.


Blead the fluid, twice. No change. Brakes have lots of life left, the calipers have had new washers and pistons greased quite recent.


I have no idea now. The brakes work And they work good. But there's not a lot of working space at all... brake lever comes all the way in pretty much.


....the good news is my rear caliper is back to full working order (so you can now try my bike Joe) lol.

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Try keeping the pressure on the brake lever as you tighten the bleed nipple.

so with fluid still pumping out, tighten it up.. as opposed to tightening it up when not pumping.

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They are braided lines.


Al, before you go spending any money on anything (including mechanics) it's worth trying again with the technique Joe suggested and I guess bleeding the lines & tying the brake lever over night to get all the air out I suppose. Other people have had success with that, might be worth a pop.

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Hi bleed the brakes get some pressure in the lever, then get a tie wrap and squeeze up the lever and lock it with the tie wrap leave it for a while preferably overnight, cut it loose that should sort it.

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Holding the lever back over night does not get rid of the air


All it does is compress it and it feels good for a few days!

And using it together with a vacuum pump?? (i.e suck out everything, then set the lever, then put fluid in...???)

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Set the lever?


For christ sake don't drain the fluid unless your stripping the brakes! You will just cause more of a headache!


What make are the calipers?

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Just to add in...


You need to let the fluid sit in the bottle for a day or two to remove the air from solution before you put it in your brake system.


If you've got old/wet/aerated fluid and you're heavy on the brakes then you can get bubble formation in the callipers due to the increased heat (sounds like what may have happened in the first place).


Some callipers are a sod to get the air out of. Mine required loads of tapping with a spanner and rotating around to finally get the air out.

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Holding the lever back over night does not get rid of the air


All it does is compress it and it feels good for a few days!

Agree Stu, you won't get rid of the air this way. l always do this after l've completely removed the air from the system, as you say it firms up the lever. Hydraulic oil should never be left exposed to air, moisture in the air contaminates the oil. When you think your oil is boiling it is in fact in most cases the moisture in the oil thats boiling.

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I need to rebleed them anyway. My calipers are tokico 4 piston. Surely if you pull tie the lever overnight and then bleed the nipple it'll then release the remaining air?


I'll see I anywhere is open today and try something out!

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Tokico 4 pots explains a lot!


They are shit :lol:


They are the world's worst calipers for allowing shit behind the seals and reducing performance


With this info I would go straight to a caliper rebuild


You might get away with not replacing the seals


But you must clean the seal groves


The groves get full of shit and push the seals against the pistons which causes all sorts of problems from sticking pistons to excessive lever travel


I used to rebuild the tl ones every year until I replaced them with nissin calipers

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