ABS Spongy Brakes.

First topic message reminder :

So ever since i put braided lines on my ABS 1250, the brakes have felt like sh*t.
Only rode her a couple of times then the rego ran out.
Now that Cherry is going to be back on the road, i thought id better fix them.

Well...i cant.
Ive bled them each and every way. All fresh fluid and brand new pads.
After using a whole bottle of fluid, and not getting a single bit of air i gave up.
Im a mechanic, so i know how to bleed brakes...but it frustrates me that i cant get them better.
Ive even done the trick of cable tie-ing the brake lever in over night. Did nothing.
The lever comes all the way into the bar.
It brakes ok at normal speeds, i just dont trust it in an emergancy. And there is nothing worse than not having confidence in your brakes.
Ive done searches on all other bandit forums. There are LOADS of people with the same problem (only on ABS models), but no cure.

The only thing people can come up with, is that 80% of the abs lines are steel. The only rubber lines are at the front. So braided lines will flex more than the original steel ones. So maybe replacing all the steel lines, with more flexible lines, make the brakes spongy. Makes sense.
The other thing people suggest, is that it might be easy to get an air lock in the ABS module and not so easy to get it out.

Anybody else here replaces lines on an ABS model?

Its spongy dead cold or hot. Makes no difference.

As for checking with the dealer, they say they bleed just like you would at home. No difference.

Go into supercrap/repco and get yourself a large (and I mean ken huge) syringe and some tubing (best is clear type) that will fit over the bleeder nipple. You can use this for bleeding in a similar way to what the phoenix tool does.
Might get you a better lever until your new bleeding toy turns up.

EDIT: here is one I prepared earlier

Reverse bleed is how I would do my MTB hydraulic brakes (Hayes Nines for anyone interested), works great. Never tried it on a motorbike system, always gone traditional which has always worked so far. Never had to do an ABS system yet, so not encountered the frustration. However it does sound like an air bubble somewhere. The only trick I can suggest based on past experience is to use a hammer and I don't mean the business end of it. Hold the head and use the handle (hopefully a wooden or rubber handle) to tap the line/junctions etc gently. Hopefully with some gentle persuasion if there is a bubble in the line, you will dislodge it or agitate it enough so it can rise out of the line to the master cylinder.

With the reverse bleed option, use two syringes, one to force the fluid in, the other to remove any excess from the master cylinder to save spillage. The Hayes Nine bleed kits for the MTB had a special venting hose that attached to the master cylinder so the excess drained away. Maybe there is a market in making a venting cap for motorcycle brake/clutch bleeding kit?

Hows this for a thought?
What diameter brake lines are the new ones Cam?
If they are larger than stock the m/c won't be pressurising enough fluid to make them work. A poofteenth will be enough to make a difference.

I'm talking about fatter lines equals more surface area to pressurise before anything works.

2wheelsagain wrote:Hows this for a thought?
What diameter brake lines are the new ones Cam?
If they are larger than stock the m/c won't be pressurising enough fluid to make them work. A poofteenth will be enough to make a difference.

I'm talking about fatter lines equals more surface area to pressurise before anything works.

this is fact, smaller diam equals higher pressure,and think you`ll find most sports bikes MC`s have smaller journals for higher pressure.(this is what i`ve been told and lead to believe along with a bigger piston)

when i put braided lines on,i didn`t notice to much of an improvement,but when i put a gix MC on,i noticed a big improvement

service manual doesnt indicate anything with regards to ABS.

I mean, they dont indicate it has a separate resevoir or special bleeding instructions (except to say you should use stock tyres which would induce lots of bleeding).

could it be a seal in MC?

dumbest idea ever but..

have you taken the bike over some bumpy roads to see if any air pockets will bubble up to controls?

cheers

I just replaced my top line in order to fit barbacks (better fit for the DL1000 hand guards). The shop who made up the line used a vacuum bleeder fitted to their air line to get the air out. It was a difficult job and took a lot of fluid. Tying the lever back overnight after that gave me the best lever feel yet. I can't get it that good hand bleeding it. It was a headache even for the professionals.

Can this be an issue on non ABS bikes? Mine has a soft front brake that has been dealer bleed. It has braided lines also.

wouldn't have thought so , I changed the fluid on my 04 1200 non ABS with out drama & that had braided lines

I was reading a post on another forum which reminded me of a bleeding problem when I had a Suzuki Marauder VZ800

Following a master cylinder overhaul I had the spongiest brakes in history.

I unbolted the caliper, placed a spacer in place of the disc rotor and raised up above the master cylinder. This resulted in more air expelled and a great brake.

With regard to the Bandit, unbolt the left side caliper, insert a spacer and raise the caliper to a point where the hose joining both calipers is rising. Bleed.

BanditDave wrote:I was reading a post on another forum which reminded me of a bleeding problem when I had a Suzuki Marauder VZ800

Following a master cylinder overhaul I had the spongiest brakes in history.

I unbolted the caliper, placed a spacer in place of the disc rotor and raised up above the master cylinder. This resulted in more air expelled and a great brake.

With regard to the Bandit, unbolt the left side caliper, insert a spacer and raise the caliper to a point where the hose joining both calipers is rising. Bleed.

I was thinking something similar, I seem to recall the story of a vehicle where you had to suspend it with a winch to get a good bleed.
Maybe if you hang the bike from the front or depending how the plumbing runs, some other way, you can get the bubbles somewhere that they can be eliminated from?

NZspokes wrote:Can this be an issue on non ABS bikes? Mine has a soft front brake that has been dealer bleed. It has braided lines also.

For the 1250s it's an issue for the ABS models, although anything can have a soft lever. I haven't complete faith in dealers either!

No abs on mine and brakes not spongy .Before or after fitting lines .Did feel better with new pads though .
Could it be they get spongy as pads wear down ?

hey cameron,what braided system have you got?(i`ll say sorry now if you`ve said it,and i didn`t read it)

have you got 2 seperate lines,or a splitter box?(i don`t know the typical layout of ABS)

If splitter,that could be your prob,with air trapped in there!

if you got 2 seperate lines,and still no good,then i can`t help

I've got a mate with a VW trike.

He tried all the fancy techniques without success.

His final solution was to put the front wheel on a saw horse to get a successful bleed - this seems to be a similar issue.

I cannot understand how all the fancy bleeding techniques have less success whereas something as simple as raising various parts seems to get a result

So i rode it, activated ABS, bled the system, no different.

Took it for a decent ride just to see how the brakes feel. They where still a bit spongy, but they are good enough to ride with. ABS kicks in, so they work to their full potential, as ABS comes in before the lever comes all the way into the bar.
Reverse bled with the biggest syringe i could find. much better now. Still not great, but better. i think its the best i am ever going to bet them. They are probably equally as good as they where before the line change, so i cant complain there.
I put the braided lines on to improve the feel..that didnt work. But now they are as good as they where before, im happy.
Means i can go riding again

Pretty disappointing outcome really

I thought the whole point of braided lines was to improve the brake feel and reduce the spongy feel caused by line expansion? I have been planning on putting braided lines on mine but I am having second thoughts after reading your issues.

I might have to get a quote from a Garage to have them fitted and then if they turn out as yours have i can just take them back and get them to re do them.

if it has abs, maybe have a think about it.
If its not abs, go for it. deffinately worth it.

I always take the calipers of and try to get them higher than the master cylinder to bleed them.

I was speaking to Buellord once who has the exact same bike as mine. He told me not to waste my money on braided lines as he did and they were no better. He reckoned best bang for buck was a set of HH pads. SO I went down that line and they are a fair bit better than the stocks.

Braided lines was on my "mod" list but after reading this thread I have put a line thru it , One of the few gripes I have with my 1250fa so far is the stopping power of the brakes , the bike pulls up ok but the brakes just dont feel they are as good as they should be

The Haynes manual recons that on an ABS Bandit you start by bleeding the Left hand calliper first. On non ABS bandit you bleed the Right hand calliper first. Might help.