bleeding 6 pot tokico's

[Paul the 6th]

2 hours I've been soaking my hands in brake fluid & still the brake lever is coming to within an inch of the bar/air is teasing me by coming out in hundreds of bubbles & then none at all for 5 minutes...

I've had the calipers to bits, pistons out & cleaned, new fluid & dust seals, new rings between the caliper halves, everything tightened up as per manual torque settings, fitted back on the bike, banjo's tightended up to correct torque...

I've got a bit of clear tubing over the bleed nipples so I can see the fluid & air bubbles coming out. Every so often the bubbles stop appearing in the fluid so I nip the bleed nipples finger tight, pump the lever quickly a few times & it gains a bit of back pressure. If i then let go and pull it once, it's back to being rubbish again.

Am I doing something wrong?

[Wideboy]

are they braided lines? or standard with a Y in the middle?

if they have a Y and your bleeding individually start with the one furthest away from the handle.

when i done the gsxr front end it took me about an hour to pump it through :rolleyes:

also depends on what bleeder you have, i find the automatic ones that circulate back to the top are quicker

edit: oh and before you nip up the nipples pump the leaver and hold it in whilst you tighten the nipple

[Paul the 6th]

It's standard lines with one line going to offside caliper, then from offside over the mudguard to nearside. Started with nearside, then swapped to offside, then back to nearside, then back on offside and about to go back to nearside...

I've used nearly a litre of brake fluid and lever is still no where near = that CANNOT be right..

[Wideboy]

you sure you aint just ****ed them up? :lol:

[Paul the 6th]

oh yeah i almost forgot to tell ya gav, f*** off

[barwel1992]

bolt the bleed nipples up and sit on the bike with rez cap off, hold the leaver in and shake the bike, then when no more bubbles appear in the rez, try and re-bleed, if loads of bubbles are still coming through the tube then you more than likley leaking air in some where
literally took me 15 min to do my brakes on the sv this way but had braided hoses

[Paul the 6th]

yeah I've been waiting on YC to sort out braided lines...

Already tapped the calipers with a wooden mallet as suggests by a few guys on gixerjunkies.

Been at it for nearly 3 hours now, gonna stick it in the garage for the night with lever tied back.

If i don't murder anyone with pure rage in the meantime, I'll report back tomorrow...

[BBadger]

Read your post on JG...i think giving the bike a shake/ tilt might help as there could be bubbles stuck in the top banjo just after the mc which might not be shifting ??

[Paul the 6th]

ironically enough I've bought a brembo master cylinder off a guy on GJ - it's got a bleed nipple on it but the stock one doesn't grrrr

Will drop bike off paddock stand and give it a shot before packing up for the night and getting p*ssed

[Dave20046]

Is there a bike between the reservoir and the mastercylinder? If so you'll need to squeeze that bike every so often. Worth leaning the bike over so the masterclinder is the highest point and giving a go like that for a bit, also tap your lines. Make sure all the banjos are torqued up.


Squeeze open/close release etc.

[yorkie_chris]

Those bubbles coming through tube are probably getting sucked in through threads of nipple, not fluid in caliper.

Bleed the banjo bolts out and make sure you haven't got air trapped by master cyl banjo pointing uphill!

[Paul the 6th]

I sussed that out after about 30 mins YC lol..

Gareth from redcar suggested undoing the top banjo bolt ever so slightly but that hasn't changed it. No visible leaks anywhere around the calipers.

Just gonna park it up with the bar pulled tight for the night. Thinking of betting £50 that it won't make a blind bit of difference but I'm skint right now :rolleyes:

bag o shiit, well ****ed off.

ta for all the advice, apart from gav, you can go get swine flu buddy :razz: x

[Girth]

I had issues with mine so i back bled it with a syringe, mainly to get fluid through the system tho.

[Paul the 6th]

lol got back from road testing it, so dangerous I giggled to myself...

Then I was popping it on the paddock stand but the arm of the paddock stand had slipped under the chain and ended up tipping the bike over. It happened in such slow motion I was able to dive under the bike as it went down. They're heavy enough lifting up when you're stood next to them but when you're trapped under one...

FFS WHAT A SHIIT DAY

[Paul the 6th]

i dried/cleaned both calipers before parking up with the lever tied back - it seems the nearside caliper is seeping brake fluid so I'll have to dismantle and inspect tomorrow if I've got time :( atleast I've sussed the problem :rolleyes:

thanks for everybodies input though :)

[fastdruid]

FWIW I've had good results in pumping the pistons as far as they will go (without risk of coming out), tapping everything to move air as high as it will go, leaving a while before pushing the pistons back in.

Druid

[yorkie_chris]

If you are getting leakage that is why it is not firm!

If there was a pit in piston then it may have scored new seal, or fluid is getting past that seal on initial pressure then firming up.

[AndyBrad]

fluid out = air in im afraid chap. bleeding can be a right pain in the ass ive gone through a litre of fluid before now!!! its a right royal pain in the ass.

As people have said once youve got it fixed you can start at it again oh and dont use one of those easybleed kits!!!

[yorkie_chris]

If it takes you a liter of fluid then you missed something, just pushing fluid through the same route will not clear any more air than the first bit.

[Paul the 6th]

If you are getting leakage that is why it is not firm!

If there was a pit in piston then it may have scored new seal, or fluid is getting past that seal on initial pressure then firming up.

Oh hell, if only I had realised that's how braking systems work! :razz:

The pistons are mint to be honest. I think only one of them had a tiny bit of tar/road dirt right on the upper edge which I spent long enough trying to remove so ended up leaving it...

None of them had any mega pits or corrosion on them so I reckon one of the o-rings which go between the two caliper halves may have dropped out or may not be seated right..

Still, I'm chuffed the problem has identified itself so I can start trouble shooting it now. Thinking a mityvac & 4 pots will be the way forward in future though!

[yorkie_chris]

Mityvac schmityvac. Get a couple of 25ml syringes they cost nowt and do same thing

[andrewsmith]

a liter is a lot of fluid. I did a seal change and bleed with 250ml.

And that was with around a good half wasted getting the pistons out and cleaning out the washing out the calipers

[Lozzo]

I had issues with mine so i back bled it with a syringe, mainly to get fluid through the system tho.

Triumph pump fluid up the lines from caliper to m/cyl at the factory when they fill the system from new, they don't need bleeding afterwards either.

[Lozzo]

Junk the 6 pots cos they are crap. Put some Nissin 4 pots off a Bandit 1200 on if the spacing is 90mm between the bolt centres. I recommend the Bandit Nissins because the calipers are hard anodised all the way through the working bits, including the piston bores and seal grooves, unlike all Tokicos which are bare alloy in there and suffer badly from corrosion.

My housemate has Bandit 1200 calipers on his ZX7R after junking the standard 6 pots, and with a stock ZX10R radial m/cyl they are fantastic brakes.

[yorkie_chris]

SRAD spacing is 90mm, b12 ones will fit.

TBH there's nowt wrong with the 4 or 6 pot tokicos if you keep up to the maintenance.

[Lozzo]

SRAD spacing is 90mm, b12 ones will fit.

TBH there's nowt wrong with the 4 or 6 pot tokicos if you keep up to the maintenance.

They require too much specialist maintenance to be a viable proposition for the average owner who isn't as mechanically minded or doesn't have as well equipped workshops as us. Bloody things need stripping and cleaning far too frequently even for me to be bothered rebuilding them just the once. They'd be the first thing I'd junk on any bike I intended to keep for any length of time

[Paul the 6th]

SRAD spacing is 90mm, b12 ones will fit.

TBH there's nowt wrong with the 4 or 6 pot tokicos if you keep up to the maintenance.

Apparently the 6 pots are great, IF they're maintained properly and work right. Quite a few people have said they're a biatch to bleed though

Junk the 6 pots cos they are crap. Put some Nissin 4 pots off a Bandit 1200 on if the spacing is 90mm between the bolt centres. I recommend the Bandit Nissins because the calipers are hard anodised all the way through the working bits, including the piston bores and seal grooves, unlike all Tokicos which are bare alloy in there and suffer badly from corrosion.

My housemate has Bandit 1200 calipers on his ZX7R after junking the standard 6 pots, and with a stock ZX10R radial m/cyl they are fantastic brakes.

And yeah, alot of people have also said the same about ditching 6 pots for 4 pots as they're usually just as powerful (if not a little bit more) but require far less maintenance...

Gonna pull them apart when I get home from work tonight

[AndyBrad]

yea the l of fluid was because i had just had the brakes serviced and they wernt really bled properly. i did it a lot expecting them to go solid and just couldnt get the air out of them. Strangly enough there was a lot of the dye from the red rubber grease comming out with the fluid as well. It was quite strange. Anyhow i replaced the lines with briaded ones thanks to dave numbers and they were still shocking brakes. In the end i rebuilt them with new seals and hey presto fantastic brakes.

I recon that took a lot of fluid.

[_Stretchie_]

Those bubbles coming through tube are probably getting sucked in through threads of nipple, not fluid in caliper.

I was going to mention this. I had the same when I put braided lines on the Thundercat. Fannied around for hours bleeding.

In the end I took the bleed nipples out wrapped some PTFE around the thread and put them back, pulled the fluid through with the Mytivac and then bled them normally (bottle, brake fluid and spanner) was done in about 20 mins

[Dave20046]

Not looking forward to doing mine tomorrow :(

[philbut]

Funnily enough I've had the same issue rebuilding my mates YZF750. i can get them nice and firm using the "tie the lever back over night" method but they quickly loose firmness. Turns out one of the calipers is leaking from between the casting. They are sumitomo 6 pots, so very similar to the Tokikos. Guess what I'm doing tonight...

Incidentally, I have put Busa 6 pots on my 7R with a standard M/C and they are fine. no problem to bleed (I use a syringe and fill from the bottom with pistons fully in). Its only my fun bike so I don't mind rebuilding them once a year anyway.

I put 4 pot Nissins (from an '01 Blade) on my ZZR as that is my high mileage bike and I CBA to rebuild them all the time. Works fine, but could do with a bigger M/C as the ZZR one is a bit smaller than the Blade.

EDIT -I do agree that as a rule, the old school non radial Tokico callipers are sh1te. The metal is too soft and they do suffer terrible from corrosion. I rebuilt and painted my old tokicos on the ZZR twicebefore giving up and swapping for the Nissins.

[Paul the 6th]

yeah the nearside caliper was leaking from between the castings as well - rebuilt but not gonna have chance to get them back on the bike until monday now = 15,462 jobs to complete before then!