EuroKClub

General forum area => K1200 / K1300 Forum => Topic started by: Grumpy jase on March 15, 2024, 02:01:52 pm

Title: Brake woes
Post by: Grumpy jase on March 15, 2024, 02:01:52 pm
I ride my bike all year round, and through this winter it has got pretty grubby and my pads were starting to bind a little.  So took the callipers off, pumped the pistons out a bit to clean them (not too far), and then pushed them back all the way in.  They were actually moving pretty freely.  Cleaned up the pad backplates and the calliper body, as the corrosion was causing the pads to bind in this area.  Put it all back together.  Did this on both front and rear pads.  However, I cannot get the pads to pump out against the discs, seemingly having just endless travel on either front or rear levers.  I've started the bike, and moved it far enough so the ABS light and Brake failure message is no longer illuminated, but still nothing.  I'm guessing I have a problem with the ABS pump, but before I go too far in this direction does anyone else have any ideas.  I do not have a GS911, so can't run diagnostics via this.
Thanks
Jason
Title: Re: Brake woes
Post by: raesewell on March 15, 2024, 03:51:35 pm
If the ABS is not working you should still have normal braking just without the ABS.
Title: Re: Brake woes
Post by: Sutty on March 15, 2024, 03:56:37 pm
I did the same thing last year, you need a GS911 to bleed the ABS pump. I tried all ways in the end I stumpped up for a second hand one from ebay, i did both front and back with the 911 , they're as good as new now. plus I made some blocks to stop the pistons coming out too far next time.

Best regards  Mick
Title: Re: Brake woes
Post by: chriscanning on March 15, 2024, 04:03:16 pm
You haven’t got snowballs chance in hell of sorting without a GS911.
Title: Re: Brake woes
Post by: Phmode on March 15, 2024, 07:23:44 pm
I don't understand what it has to do with the ABS. Nothing was bled or drained and refilled so there should be no fluid pressure issues to need sorting.

I've changed my front brake pads twice and run the pistons in and out (a little) and back in and never had a pressure or travel problem.

Seems odd to me.
Title: Re: Brake woes
Post by: richtea on March 15, 2024, 08:40:26 pm
I don't understand what it has to do with the ABS. Nothing was bled or drained and refilled so there should be no fluid pressure issues to need sorting.

I've changed my front brake pads twice and run the pistons in and out (a little) and back in and never had a pressure or travel problem.

Seems odd to me.

Agreed. I did this about 2 weeks ago with no loss of pressure.
Title: Re: Brake woes
Post by: nealchaykin on March 16, 2024, 01:12:21 am
Just a random thought, have you checked the reservoir?
Title: Re: Brake woes
Post by: chriscanning on March 16, 2024, 07:47:19 am
Had the ABS warning come on and I’d done nothing and with an XR that would tell me it needed servicing when it didn’t a 10 vin GS911 was just a fact of life.
Title: Re: Brake woes
Post by: Sutty on March 16, 2024, 01:53:02 pm
Guys when I screwed mine up I was fitting new pads, I thought while the pads were out i'd take the opportunity to clean the pistons. I pumped them out gently but not gently enough and popped one thus needing bleeding. I bled them as normal but although they worked they were too spongy for my liking
some people said on various forums you don't need to bleed the ABS but believe me you do !  and, you can't do it without the GS911, or some other program that does the same function. Afterwards the feel is perfect and solid.
Like I said I have now made up some stops to fit in the calipers to stop the pistons coming out too far.

Best regards   Mick
Title: Re: Brake woes
Post by: Grumpy jase on March 16, 2024, 05:29:54 pm
Hi all, thanks for your thoughts and help.  With your comments I came to the conclusion it should still be a simple mechanical issue.  Removed the rear calliper again, and could see the pistons moving out, but immediately back in when I released the lever.  Seems the pistons were moving very freely, maybe because the pads need replacing, and the piston needs to be quite a long way out.  Re fitted and then used a plastic trim tool to apply a little friction to the piston to stop it pulling back, and seems to be sorted.

Re looked at the front, which was sort of working, but too much travel.  Close inspection found the tiny bleed nipple on the master cylinder.  Decided to try and bleed this, which did reveal a small amount of air here.  I'd not let any in, but the front has not felt brilliant for a while. Front now feels much better.

I need to do a test ride tomorrow but I'm optimistic I've got it sorted.
Jason
Title: Re: Brake woes
Post by: Phmode on March 16, 2024, 06:04:35 pm
Has your front brake master cylinder got the yellow mesh foam insert fitted. I remember this was a non-recall to sort out air entering the master cylinder due to fluid sloshing about under hard braking but I can't remember when the non-recall was done  ::)
Title: Re: Brake woes
Post by: Grumpy jase on March 16, 2024, 08:41:53 pm
Yes it does.  Never seen anything like that before, so good to know why it's there.
Title: Re: Brake woes
Post by: rich8000 on March 16, 2024, 09:00:04 pm
If your stuck I'm not too far away in Plymoth with a GS911, just need a sunny day to ride up :-)
Title: Re: Brake woes
Post by: Phmode on March 16, 2024, 09:12:08 pm
Yes it does.  Never seen anything like that before, so good to know why it's there.

A friend lost most of his braking effort riding home across mainland Europe due to frothing of the fluid. Don't know why it happened on the K and not on other bikes but the next thing we hear is the addition of the mini loofah in our master cylinders.
Title: Re: Brake woes
Post by: Capt Howdy on March 17, 2024, 05:41:13 am
It sounds as though you’ve introduced a lot of air into the system. Did you let the master cylinder run dry?  I agree that the abs unit won’t cause that problem. The gs911 allows you to replace the old fluid with new stuff.  If you don’t use it the old fluid remains. If you’re going to do your own work a gs911 is indispensable. Don’t get the cheap copy made in China. It’s loaded from a cd and can’t be updated.
The piston seals should have the pull the pistons back from the disc to stop rubbing
Title: Re: Brake woes
Post by: Forcefield on March 17, 2024, 02:00:58 pm
Following this... i too have had my pads off recently. Only to clean/service things so not fitted new ones, not moved the pistons much other than to get the calipers off. But Ive notice this week that my front brakes are very spongy. theres too much travel of the lever before any braking happens, and when it does its very soft.

Im new to K's, so I dont know how sharp they are ment to be, but Im guessing it could throw me off like a bucking horse if i squeezed too hard?
Title: Re: Brake woes
Post by: nealchaykin on March 17, 2024, 02:21:12 pm
How are your rear brakes? Mine have always been on the ‘spongy’ side but I think I read somewhere that that is usual for a K. I’ve never locked my rear brakes no matter how much the brake pedal is pressed.
Title: Re: Brake woes
Post by: Phmode on March 17, 2024, 03:29:55 pm
Following this... i too have had my pads off recently. Only to clean/service things so not fitted new ones, not moved the pistons much other than to get the calipers off. But Ive notice this week that my front brakes are very spongy. theres too much travel of the lever before any braking happens, and when it does its very soft.

Im new to K's, so I dont know how sharp they are ment to be, but Im guessing it could throw me off like a bucking horse if i squeezed too hard?

The ABS won't let it toss you off unless you are holding on with only a couple of fingers. The rider manual advises to grab the brake lever hard and let the tech do the work.

I have only ever triggered the ABS a couple of times, once in panic and once in desperation. It's a big bike and it has the brakes to match so if they are spongy or lacking feel then something is not quite right.
Title: Re: Brake woes
Post by: Forcefield on March 17, 2024, 03:37:09 pm
My rear seems ok. I have had a weird knocking through the pedal a few times when approaching a junction to stop. I believe this is the abs kicking in...

The front just feels too weak and soft. I did open the reservoir cap the other week, as I didn't know there was a sponge in there and was wondering what it was. Maybe I introduced some air into the system somehow? I'm pretty sure when I bought the bike, when I qst tested the brakes I was impressed with the sharpness.
Next dry day I get in gonna go try a few emergency stops and see how they feel perform
Title: Re: Brake woes
Post by: Phmode on March 17, 2024, 06:27:18 pm
The only way to get air in to the system is by letting the fluid level drop out of sight, dismantling a hydraulic fitting, pushing a piston out past the seal or incorrect bleeding. Other than that, a hydraulic leak would show you had a line integrity problem.

Hydraulic fluid is hygroscopic, (it absorbs moisture from the air) so old fluid may well be contaminated and therefore compressible as the water turns to steam next to the pistons and the water gets in to the fluid in the first place because the cap on the reservoir is ventilated.

Those of us who don't pay the man to do the annual service always run the risk of contaminated fluid.
Title: Re: Brake woes
Post by: TomL on March 17, 2024, 10:48:31 pm
A tip to improve the front brake is to park the bike on the side stand with the steering fully to the left. Pump the brake lever and tie it back to the handlebar. Leave overnight. I use a cycling toe strap to pull the brake lever back to the bar.

Supposedly air in the system migrates upwards to exhaust out through the fluid reservoir which is the highest point.

Works on mountain bike hydraulic front brakes as well.
Title: Re: Brake woes
Post by: Phmode on March 17, 2024, 11:01:59 pm
Nice tip Tom. I've heard it before and forgotten it  ::)
Title: Re: Brake woes
Post by: andym2 on March 18, 2024, 09:48:36 am
I put a Rekluse left hand rear brake kit on my CRF and that was the only way I could get the air out of the line from the lever down to the rear master cylinder.
Title: Re: Brake woes
Post by: Grumpy jase on March 18, 2024, 12:23:18 pm
If your stuck I'm not too far away in Plymoth with a GS911, just need a sunny day to ride up :-)

Thank you so much for the offer.  Did a good ride out yesterday, positively spring like in Mid Devon, and brakes felt great.  It felt like the small amount of air in the front had been there for a while as they felt sharper than I'm used to.  Rear is still a bit soft, but I'm putting that down to heavily worn pads, and will re-assess once the new pads are fitted.
Title: Re: Brake woes
Post by: Forcefield on March 18, 2024, 03:11:08 pm
If your stuck I'm not too far away in Plymoth with a GS911, just need a sunny day to ride up :-)

Thank you so much for the offer.  Did a good ride out yesterday, positively spring like in Mid Devon, and brakes felt great.  It felt like the small amount of air in the front had been there for a while as they felt sharper than I'm used to.  Rear is still a bit soft, but I'm putting that down to heavily worn pads, and will re-assess once the new pads are fitted.

Great to hear! what did you do to fix?
Title: Re: Brake woes
Post by: chriscanning on March 18, 2024, 04:08:04 pm
Did the rear brake bleed last night,cap back on the res,tighten it and all is good,go out for a test run this morning doesn’t feel right and then brake warning light comes on  :evil: and I’m thinking Jeeze….just about to phone my other half to bring the van!!! Have a look at rear res see I’d tightened the top too much and it had twisted in the metal clip twisted the rubber brake pipe  :o,twisted res the other way and all’s good….phew
Title: Re: Brake woes
Post by: Forcefield on March 18, 2024, 07:41:48 pm
Did the rear brake bleed last night,cap back on the res,tighten it and all is good,go out for a test run this morning doesn’t feel right and then brake warning light comes on  :evil: and I’m thinking Jeeze….just about to phone my other half to bring the van!!! Have a look at rear res see I’d tightened the top too much and it had twisted in the metal clip twisted the rubber brake pipe  :o,twisted res the other way and all’s good….phew

Phew... Close one, and pretty scary
Title: Re: Brake woes
Post by: Phmode on March 19, 2024, 05:45:35 pm
Of all the weird stuff. Nice spot though.
Title: Re: Brake woes
Post by: alaskier on March 19, 2024, 07:29:24 pm
Just a thought but how long has the brake fluid been in the system? It should be changed every two years or so. If left in too long the brake gets all spongy so that may be your problem
Title: Re: Brake woes
Post by: Phmode on March 19, 2024, 07:33:56 pm
I put a Rekluse left hand rear brake kit on my CRF and that was the only way I could get the air out of the line from the lever down to the rear master cylinder.

Flash git  ;D

I couldn't justify the expense on my Rally so tried, in vain, to fabricate my own out of bits of bicycle levers and cables but gave up because there was insufficient room on the bars to have a second lever. I have reduced sensitivity in my right foot so really liked the idea of the Rekluse kit.
Title: Re: Brake woes
Post by: Grumpy jase on March 26, 2024, 09:24:21 am
Update,
Fitted the new pads over the weekend, fronts went on no problem, but the rears again didn't want to push out, and were just pulsing in and out with the lever.  The lever seemed to have a lot of travel.  With the below post in my head, I checked the rear reservoir and found the same with the supply hose severely twisted.  I unclipped the reservoir and turned it through 2-3 full turns to untwist the hose.  Now everything is perfect, thanks Chr1s for this little gem!  The rear reservoir is merely held on with a C shaped clip, with nothing to stop it rotating, I would suggest checking yours.

Did the rear brake bleed last night,cap back on the res,tighten it and all is good,go out for a test run this morning doesn’t feel right and then brake warning light comes on  :evil: and I’m thinking Jeeze….just about to phone my other half to bring the van!!! Have a look at rear res see I’d tightened the top too much and it had twisted in the metal clip twisted the rubber brake pipe  :o,twisted res the other way and all’s good….phew
Title: Re: Brake woes
Post by: raesewell on March 26, 2024, 10:11:04 am
We like a story with a nappy ending  :thumbsupgood:
Title: Re: Brake woes
Post by: Phmode on March 26, 2024, 10:14:11 am
There are small serrations on the clip or the plastic reservoir to stop it turning inadvertently in normal use.

If you twist the bottle you can feel and hear the clicks as the serrations move against whatever it is that stops it turning normally. The only way that the thing can turn in the clip is if the top has been butchered on wayyyy too tightly and has twisted the whole shebang as Chris admitted he had done.

One wonders if the dealers just let the apprentice do the job. For those of us who still use the dealers it is yet another thing to check before we blithely ride off into the sunset...  :o
Title: Re: Brake woes
Post by: andym2 on March 26, 2024, 03:30:12 pm
I put a Rekluse left hand rear brake kit on my CRF and that was the only way I could get the air out of the line from the lever down to the rear master cylinder.

Flash git  ;D

I couldn't justify the expense on my Rally so tried, in vain, to fabricate my own out of bits of bicycle levers and cables but gave up because there was insufficient room on the bars to have a second lever. I have reduced sensitivity in my right foot so really liked the idea of the Rekluse kit.

It's got a Rekluse clutch as well, so it doesn't matter that the clutch lever is in a slightly odd position to accommodate the extra brake lever.
Title: Re: Brake woes
Post by: Phmode on March 27, 2024, 09:38:46 pm
Nice set up. The problem with the Rally is that there is no spare room on the bars and what there is is in the wrong place for a rear brake lever.