ABS Spongy Brakes.

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?

Certainly sounds like air , but I've not stuffed around with ABS brakes so not much help I'm afraid

Ill be taking it down to the local dealer on saturday to see if they have a solution.
Im not holding my breath though.

So you have constantly hit the caliper with a nylon hammer as the fluid is going through ?

There are a few little tricks to getting a good lever on the ABS brakes.
I'll try to find the post I did a while ago on teh same subject. If I can't find it I'll write it all again tomorrow night for ya.

Here it is. Maybe it'll help you.

The history of my brake mods.

I have never particularly liked the feel of the lever on the 1250SA. First thing I tried was the Galfer s/s line kit. Like you, I found that it was pretty much a one way trip as once you get the fixed lines out, then I don’t think there is any way to get them back in without a fairly comprehensive strip down. Like you, after days of bleeding, (yeah, tie the lever back overnight etc.) it was not notably better. Next, I tried new pads and fitted the Ferodo Street Sintered HH pads sold by DW, these did not really make much difference, maybe because the stock pads are HH and/or I don’t push the Ferodo pads hard enough. If you want them I have a set of Ferodo pads with about 3000kms on them.

I then tried fitting a Tokico radial m/c off a GSXR-K8 (this m/c is for sale if anyone wants). This did improve things somewhat, but still not to my satisfaction. Next step was totally off the reservation as I did the front forks and fitted the GSXR-K8 radial callipers and hel racing pattern (i.e. complete separate lines from m/c to caliper), some improvement but still not totally happy, still spongier than I like. Finally, fitted a Brembo RCS19 radial m/c…bingo now have the lever and brakes I want!

My current theory is that it is the m/c. I would try one of the Nissan 19mm (3/4”) radial m/c’s such as off a ZX10R or a CBR1000RR (both of which use similar tokico radial callipers to the gixxer but are known to have good brakes).

Warning: I reserve the right to change my theories with little or no notice

Sorry mate, i cant remember if yours is ABS or not?

Problem is, after the install of the braided lines, the lever is much worse than before. It was never great (the reason i bought braided lines), but now worse. Which makes me think its just air trapped somewhere.

Gus ill try your little trick with the hammer. Ill even give the ABS module a little tap too, cant do too much damage. Famous last words.

Was ABS but have not yet managed to incorporate it back in. I did buy a mityvac vacuum bleeder from DW and that has helped a lot. I'd also give the reverse bleed a go.

Dekenai wrote:Was ABS but have not yet managed to incorporate it back in. I did buy a mityvac vacuum bleeder from DW and that has helped a lot. I'd also give the reverse bleed a go.

Yeah ive tried vacuum bleeding. No difference.

Previously with my wifes old dirt bike (Suzuki RM80) I rebuilt and bled the brakes and they were horribly spongy. I ended up cracking the Banjo on the master cylinder just slightly whilst depressing the brake and then nipped it up. Bloody air bubble in the Banjo it sorted itself after that and front brake came back nice and stiff.

Well im going to have another crack this weekend. Ill try cracking all the banjo bolts and see what happens. Ill do the same thing at the ABS module as well.
There has gotta be a way me thinks.

Just be careful with the brake fluid, you don't want to ruin the paint. When I did mine I got a small drop on the tail section and it lifted. I wasn't totally devastated, the bike needs a respray anyhow.

Yeah ill be careful.
Ill cover everything up.

Are you bleeding with the ign on or off. It can make a difference when the bike is fitted with ABS as the HU wakes up with the ign on.

it would have be air. same thing happened with mine when i first picked it up from the shop after having them fitted - lever hit the bar. so i left it there and made them do it until it was fixed - then they facked the job up again so i didnt go back - they didnt tie one of the lines near the chain back properly and the chain took a lump out of it. so i went to another shop [brian connor in brookvale] who are excellent. they replaced the damaged line and bled them - perfect. the abs ones are apparently a major pain to bleed

Well i am slightly embarrassed. I didnt even think to bleed them with the ignition on. I will try it in the morning and report back. Other wise, steve, i might take it to where you did and get them to do it.

Cam, make sure you take the headlight fuze out to save your battery when you do.

did u fix it?

so bleeding with the ignition on did not help. Only if the abs module had play in the lines i could move it around to the the bubble moving.
But then the air may not the in the module. The rear brake is solid. And it runs through the abs module. But it will have seperate plumbing in there. So maybe.
Im running out of ideas.

bleed all connection points you can reach, there may be air trapped somewhere by the sounds of it.
Try the Mcyl first as it's the easiest.
I have a few other ideas as well which I'll post soon

Seeing as you have close to nothing to lose why not put the originals back on?
Just rig them up for a test. At least you will know if its the lines or not.

i have bled from all the joints on the entire system. No luck.
I dont have the original lines anymore. they where destroyed on removal.

I may have a cure.
On the TWT forum, alot of people have used phoenix reverse bleed systems. With those, you can pump ALOT more fluid, ALOT faster than with a home made reverse bleeder kit. Everybody that has used one, says its fixed the problem 100%. so im going to order one and report back.
Also, one guy got his back to 100% with this kit, and put on a B-King master cylinder. apparently the new MC made a massive difference. So for $150, i may look into that as well. Looks like mostly a direct swap. Just have to reposition the brake line.

I will, however, have one more go at reverse bleeding. The kits are about $160 for a good one. Ill use it heaps so im happy to pay it. But before i fork out the money, ill give it one more go.

I have a Nissan radial m/c, I think the same one is used across all radial braked Suzuki's (Gixxers, Hayabusa's and B-Kings) , $120 incl postage.

Cam, whenever a late-ish model Holden gets its brakes bled, the dealer plugs in a "Tech2" hand held computer "thingie" which tells the ABS module to start pumping during the bleeding process. I dont know if the Bandits have this same function, maybe worth asking a dealer.
....just a thought.

I used to have a problem in summer with spongy front brakes (non abs) from where I park it at work, the afternoon sun shone right on it. The lever would almost touch the grip (within ~1mm) It took about 2km or so at 80kph for the standard rubber hoses to cool down and the propper feel to return. Braided lines = fixed.


The abs lines go up over the motor don't they? Maybe heating up and expanding, at least in Narcolepsy's case.