Bleeding Bloody Bleeding Brakes

[gwigs]

Hi Guys,I,m having a real hard time getting my front brakes bled.
My brakes were dragging a little bit so I pulled the callipers apart ,cleaned them and when I bled them I couldnt get
decent pressure ,you could pull the lever back to the handlebars.
So I pulled em apart again and put in new seals, boots and new pads.
Spent 6 hours trying to get good pressure...
If I clamp off the hoses or even just 1 side just above the calliper...hey presto pressure .
If I clamp off hose from master cylinder....pressure.
I cant see it being a master cylinder problem.
I have bled many brake systems on cars and never had such problems.
I,d be ripping my hair out if it wasnt so short ,just got a number 3.
Hoping someone might have some clues for me
Thanks in advance
By the way its a gsx 1100f suzi

[unstuck]

Sounds like you still have air in the caliper.:yes:

[gwigs]

Think I have it solved,some how put callipers on wrong sides last time I had them off,
the hoses need to come into the callipers from the bottom so that the bleed niples are higher
so as not to trap air.....will find out soon wont take long to swap em over.....
Found this out by googling it ......love the interweb....
Will keep you posted

[gwigs]

Think I have it solved,some how put callipers on wrong sides last time I had them off,
the hoses need to come into the callipers from the bottom so that the bleed niples are higher
so as not to trap air.....will find out soon wont take long to swap em over.....
Found this out by googling it ......love the interweb....
Will keep you posted

Thats was a good theory but they go on one side only.....still I had some hope for a few minutes

[FJRider]

Any air bubbles in the clear bleed line from the bleed nipple .. to your waste bottle ... ???

Bleed one caliper at a time. Keep the reservoir topped up.

Sounds like it's sucking air in.

[Ocean1]

Thats was a good theory but they go on one side only.....still I had some hope for a few minutes

Take the calipers off and turn them over so the bleed nipple is at the top. Find something disc thickness and flat to keep the pads in place.

If that don't help try taking the hose off at the caliper, put the caliper in a vice nipple up and bleed it there first.

[BoristheBiter]

If they are anything like the gixxer's brakes you need a vacuum pump thingy or you will be there all day.

I changed my front pads and they burped so I tried to bleed them and after 4 hrs I went to the bike shop, they stuck a little machine on them and 10sec later (ok maybe a bit longer) they where done.

They said I could do them the way I had been but it takes for ever.

[Drew]

You have trapped air in the master cylinder.

Put it at such an angle, ( I lean the bike over, and requires having only just enough fluid so as not to spill), so that the banjo bolt is lower than where the fluid enters the master. Move the lever in and out a very small amount until bubbles stop coming out.

Then bleed the calipers.

I am nearly always right when I tell people this after they have removed the lines for whatever reason, and I still have to argue half the time. So this time, I've said it, ignore me if you want.

[gwigs]

You have trapped air in the master cylinder.

Put it at such an angle, ( I lean the bike over, and requires having only just enough fluid so as not to spill), so that the banjo bolt is lower than where the fluid enters the master. Move the lever in and out a very small amount until bubbles stop coming out.

Then bleed the calipers.

I am nearly always right when I tell people this after they have removed the lines for whatever reason, and I still have to argue half the time. So this time, I've said it, ignore me if you want.

Thanks Drew I,ll give it a go

[DEATH_INC.]

What I do is get a CLEAN oilcan and pump the fluid from the bottom up to get 'em started....works every time.

[spanner spinner]

yep as allready eluded to the air is traped in the elbow of the master cylinders, I always borrow a spare set of hands and unbolt the master cylinder then tip it to a angle that puts the banjo bolt out put lower than reservoir. It will then bleed up.

[gwigs]

Tried Drews method put bike on side stand ,pressure a little bit better but
but still going around in in ever depressing circles.
Given up for the night ,but I fucken hate letting machines win,so
I aint beaten yet but extremely dissapointed,I will be victorious:yes:

[Zedder]

Tried Drews method put bike on side stand ,pressure a little bit better but
but still going around in in ever depressing circles.
Given up for the night ,but I fucken hate letting machines win,so
I aint beaten yet but extremely dissapointed,I will be victorious:yes:

Apply the brake then hold it in with a cable tie and leave it for at least an hour.

[Coolz]

One thing you could try...leave the resovoir cap loose and tape the lever hard up to the twistgrip. Leave it overnight. The theory being that air bubbles rise and it will self bleed overnight. Doesn't always work but worth a try.

[bogan]

Take the calipers off and turn them over so the bleed nipple is at the top. Find something disc thickness and flat to keep the pads in place.

If that don't help try taking the hose off at the caliper, put the caliper in a vice nipple up and bleed it there first.

+1 to this plan. Make sure to crack the banjo's a bit too, sometimes the air gets trapped in there; messy bleed but often gets results.

Also, its not just that the piston are over retracting each time?


One thing you could try...leave the resovoir cap loose and tape the lever hard up to the twistgrip. Leave it overnight. The theory being that air bubbles rise and it will self bleed overnight. Doesn't always work but worth a try.

That doesn't make any sense, if it would self bleed why wouldn't it do it without taping the lever?

[DEATH_INC.]

That doesn't make any sense, if it would self bleed why wouldn't it do it without taping the lever?
Correct, and when you pull the lever in it blocks all the return holes (how would it make pressure otherwise?), so the air has no-where to go. An old wives tale.

[Laava]

One thing you could try...leave the resovoir cap loose and tape the lever hard up to the twistgrip. Leave it overnight. The theory being that air bubbles rise and it will self bleed overnight. Doesn't always work but worth a try.

Correct. This is absolutely worth doing. I had a cunt of a time, spending a couple of days, getting my GSXR750 to bleed with all new everything and was getting sick of pumping endless fluid through it.
I bled as best I could and then if I pumped the lever quickly several times it would be just short of touching the bars. I taped it back at this point and left it overnight in disgust.
Fuck me, it works! Then the brakes were awesome!


+1 to this plan. Make sure to crack the banjo's a bit too, sometimes the air gets trapped in there; messy bleed but often gets results.

Also, its not just that the piston are over retracting each time?



That doesn't make any sense, if it would self bleed why wouldn't it do it without taping the lever?

I couldn,t for the life of me work out how it could work other than all air rising to the top of the system and then burping back into the master cyl when you release the tape.
So I was pleasantly surprised. It is a very easy try as well.


Correct, and when you pull the lever in it blocks all the return holes (how would it make pressure otherwise?), so the air has no-where to go. An old wives tale.

Yip, i was saying the same thing. Hope gwigs tries it then to see how it goes for him?

[Road kill]

Buy a set of one way speed bleeding nipples.

They have a valve in them that prevents air returning through the nipple so you don't need to open/close them during bleeding.

You just crack them and then pump away until your happy all the old fluid and air has been replaced "then nip them back up again.

Google is your friend,,I'm not.:msn-wink:

[Zedder]

Correct, and when you pull the lever in it blocks all the return holes (how would it make pressure otherwise?), so the air has no-where to go. An old wives tale.

These guys disagree: http://helperformance.com/brake-doctor/index.php?page=6

[Laava]

These guys disagree: http://helperformance.com/brake-doctor/index.php?page=6

Oh yeah, and that,s where I got the info from for my probs!
Cos I had new Hel lines.

[Drew]

These guys disagree: http://helperformance.com/brake-doctor/index.php?page=6The reason they site for dong it, sounds like bulshit to me.

The remaining air in the system is forced out. To where? Through what?

I also want to know how someone is going to "pop the brake caliper seals", by bleeding the system backwards. Anyone care to hazard a guess, as to how many PSI of pressure there are in a brake caliper, when the brakes are pulled on hard?

I think they have typed that out in a hurry, for the masses, without too much thought going into it.

[Zedder]

The reason they site for dong it, sounds like bulshit to me.

The remaining air in the system is forced out. To where? Through what?

I also want to know how someone is going to "pop the brake caliper seals", by bleeding the system backwards. Anyone care to hazard a guess, as to how many PSI of pressure there are in a brake caliper, when the brakes are pulled on hard?

I think they have typed that out in a hurry, for the masses, without too much thought going into it.

Yeah, it seems a bit of a gloss over explanation, but from what I understand (my background is geology not engineering) the tie back gives everything time to reseat properly which doesn't happen in normal cycles of use. This process then allows the air to bleed eventually.

I don't agree with leaving the top of the master cyclinder cover off though 'cos brake fluid is quite hygroscopic.

[imdying]

Sounds like it's sucking air in.You'd see fluid coming out the same hole.

[FJRider]

When bleeding the brakes (front or back) ... if two people do the job ... one works the levers (A child's play ??), the other works the bleed valve .. [you] ... it gets done quite quickly. Regular top-ups of the reservoir ... Done.

[Subike]

The reason they site for dong it, sounds like bulshit to me.

The remaining air in the system is forced out. To where? Through what?

I also want to know how someone is going to "pop the brake caliper seals", by bleeding the system backwards. Anyone care to hazard a guess, as to how many PSI of pressure there are in a brake caliper, when the brakes are pulled on hard?

I think they have typed that out in a hurry, for the masses, without too much thought going into it.

Fawk, Id never let you monkey with my brakes. What they are doing is allowing the air suspended in the fluid to seperate from the fliud and come to one point where it can be bled off. Air impregnated fluid can be pumped through a system for days and you will still get that spongy feel. Let it settle pettle, and harden up.

[imdying]

I also want to know how someone is going to "pop the brake caliper seals", by bleeding the system backwards. Anyone care to hazard a guess, as to how many PSI of pressure there are in a brake caliper, when the brakes are pulled on hard?Less than a 1000psi. That document is a bit of a laugh, but worth a read.

[imdying]

Fawk, Id never let you monkey with my brakes. What they are doing is allowing the air suspended in the fluid to seperate from the fliud and come to one point where it can be bled off. Air impregnated fluid can be pumped through a system for days and you will still get that spongy feel. Let it settle pettle, and harden up.It's rubbish. Just bleed them correctly in the first place.

[FJRider]

You'd see fluid coming out the same hole.

Only if it was downstream of the pump. An air pocket in the reservoir outlet would suck air in ... but not always the whole air bubble.

[Drew]

Fawk, Id never let you monkey with my brakes. What they are doing is allowing the air suspended in the fluid to seperate from the fliud and come to one point where it can be bled off. Air impregnated fluid can be pumped through a system for days and you will still get that spongy feel. Let it settle pettle, and harden up.

Pray then, why are they strapping the lever back? It would make no difference as to separating the air from the fluid.

I'm not offering do your brakes by the way.

[imdying]

Only if it was downstream of the pump. An air pocket in the reservoir outlet would suck air in ... but not always the whole air bubble.lul wut... Now you're just grasping at straws.

[Laava]

The reason they site for dong it, sounds like bulshit to me.

The remaining air in the system is forced out. To where? Through what?
v

As I said in a previous post, I believe it must gravitate to the top, at the master cyl, and then burp out when the lever is released. The fact it worked at all fuckin amazed me! But it did and did not need to be re done. I thought it might go spongy again but no. I am no stranger to rebuilding brake systems on my own stuff, this was a new one on me. Maybe it will only work on a system that is predominantly pointing downhill like a front motorcycle brake?


When bleeding the brakes (front or back) ... if two people do the job ... one works the levers (A child's play ??), the other works the bleed valve .. [you] ... it gets done quite quickly. Regular top-ups of the reservoir ... Done.

Yeah, nah, this did not work for me. I spent a couple of days doing this and in sheer desperation trying the taping the lever thing. Should have done it to start with but like you, refused to believe it could work.
We are not debating the existence of god here people! Just trying to help based on what worked for me.
Good luck gwigs.

[bogan]

There's probably some fandangled explanation to do with bubble size/pressure or viscosity or some shit if taping the lever does help. With the commoners just giving the simple explanation of it 'forcing bubbles to the top'. Would be interesting to know exactly how it is supposed to work though...

[Laava]

Interestingly enough, you have no way of testing this method unless you are in the situation I was and I believe from his description, gwigs has the same symptoms. Waiting to see if he tries it!

[Drew]

Interestingly enough, you have no way of testing this method unless you are in the situation I was and I believe from his description, gwigs has the same symptoms. Waiting to see if he tries it!You really are struggling with the fact, that if he does it properly, he wont need to do as you suggest.

[Subike]

molecules of oxygen (air) suspended in the brake fluid when not under pressure will just sit.
pressurize the fluid , and the oxygen particles will be forced to move, being that they are lighter than the fluid molecules, they will rise.
When the pressure is released, this gathering of the oxygen molecules will be expelled,
Im not the best at explaining this on paper, just having it explained by a hydraulics engineer when learning many years ago the principles of braking systems etc. as an apprentice mechanic attending tec.

[bogan]

molecules of oxygen (air) suspended in the brake fluid when not under pressure will just sit.
pressurize the fluid , and the oxygen particles will be forced to move, being that they are lighter than the fluid molecules, they will rise.
When the pressure is released, this gathering of the oxygen molecules will be expelled,
Im not the best at explaining this on paper, just having it explained by a hydraulics engineer when learning many years ago the principles of braking systems etc. as an apprentice mechanic attending tec.

Air is lighter than the fluid at all times though, it will always try and rise, hence the trapped air pocket problem. Or do you mean that the fluid absorbs the air when under pressure (so no air bubble)? the absorption being distributed around the fluid, so when pressure is released, so is the absorbed air, but it is released either at the top, or all over the system in minute parts which make their way to the top, thus removing air from the system.

[ducatilover]

Speed bleeders are teh shizz, I'll be buying some (thanks for the reminder)

I generally do it as Drew has said, I also move the brake spliiter around on my Kawasaki as it sometimes gets bubbles sitting in it :rolleyes: and the master... and the calipers.
Pricks of things

[AllanB]

I changed to SS lines a couple weeks back. Front end took a lot of pumps to get up to pressure - usual shit just when you are pissed off one more squeeze works!

To their credit HONDA place the bleed nipples at the top of the calipers.

I have had success in the past with removing calipers and securing them higher than the master cylinder.

Hell try the zip-tie brake lever solution - let us know if it works.

[pete376403]

Pray then, why are they strapping the lever back? It would make no difference as to separating the air from the fluid.

I'm not offering do your brakes by the way.

Holding the lever back (ie cable tie to the handlebar) will cause any air in the system to dissolve into the fluid, giving the effect of a good "hard" brake lever.
Apparently exactly the same as scuba divers getting air dissolved into the bloodstream when diving too deep (ie too much external pressure).

When the divers surface (ie the external pressure is released) the air seperates from the blood into bubbles, commonly referred to as the bends. Often fatal.

When this happens with brakes the results can be fatal also.

Unless someone can give a reasoned, technical answer about why something does or doesn't happen with brakes, unexplainable techniques are probably best avoided.

[FJRider]

I don't agree with leaving the top of the master cyclinder cover off though 'cos brake fluid is quite hygroscopic.

It's not that big an issue actually. There will be more risk of/from air in a half full bottle of fluid on your workshop shelf.

Interesting reading here ...

http://soarer.ace.net.au/brake_fluid.html

[Laava]

You really are struggling with the fact, that if he does it properly, he wont need to do as you suggest.

The only thing i didn,t try was reverse bleeding. If the tying the lever back didn,t work I would have had to take it to the motorbike shop. Believe me, I spent a lot of time trying to get this right.
You are struggling with the fact that this works.


Holding the lever back (ie cable tie to the handlebar) will cause any air in the system to dissolve into the fluid, giving the effect of a good "hard" brake lever.
Apparently exactly the same as scuba divers getting air dissolved into the bloodstream when diving too deep (ie too much external pressure).

When the divers surface (ie the external pressure is released) the air seperates from the blood into bubbles, commonly referred to as the bends. Often fatal.

When this happens with brakes the results can be fatal also.

Unless someone can give a reasoned, technical answer about why something does or doesn't happen with brakes, unexplainable techniques are probably best avoided.

I have to admit I was extremely sceptical about this procedure. So would you then expect the air to reappear as bubbles and the brakes would go spongy again? I did, but that didn,t happen. Although I have to admit I was nervous about it and eventually rebled the system with fresh fluid. This time it bled through perfectly.

[pete376403]

Possibly after tying the lever back, the entrapped air was dissolved into the fluid which made it possible to purge when you rebled with fresh fluid. Or something. Good that you got it sorted.

After fitting braided stainless lines on the front of the GS1100, I resorted to stringing the calipers up above the master cylinder, with packers between the pads to keep the pistons in, to get them properly bled and these are just plain ol single pot calipers. I coud imagine modern 4 or 6 pot calipers to be a lot more difficult without some sort of pump system.

[ducatilover]

Possibly after tying the lever back, the entrapped air was dissolved into the fluid which made it possible to purge when you rebled with fresh fluid. Or something. Good that you got it sorted.

After fitting braided stainless lines on the front of the GS1100, I resorted to stringing the calipers up above the master cylinder, with packers between the pads to keep the pistons in, to get them properly bled and these are just plain ol single pot calipers. I coud imagine modern 4 or 6 pot calipers to be a lot more difficult without some sort of pump system.
Fours are fine if you do it right. Sixes can be pretty bloody 'orrible though :facepalm: but sixes are pretty...

[Ocean1]

Fours are fine if you do it right. Sixes can be pretty bloody 'orrible though :facepalm: but sixes are pretty...

Meh. More is always better.

[ducatilover]

Meh. More is always better.
I'll agree there. I've had fun with air locks in a ZRX400's 6 pots, but got there after an hour or so

Might slam a set of gixxer/busa ones on my Krapasfaki

[imdying]

Sixes are junk for a bike. Eights aren't any less retarded than anything else Buell ever did.

You don't see six piston calipers for sale muh, or in high level racing. Bit like Buells. Funny that.

[Drew]

Sixes are junk for a bike. Eights aren't any less retarded than anything else Buell ever did.

You don't see six piston calipers for sale muh, or in high level racing. Bit like Buells. Funny that.
Yip, the front of a Buell is perfect example of why no one should try and re-invent the wheel. It cooks brakes!

[Ocean1]

What's this, the I hate Buell club? :laugh:

Or fashion victims inc?

[Drew]

What's this, the I hate Buell club? :laugh:

Or fashion victims inc?I don't hate Buell. They make my half fucked 27 year old tourer, look positively AWESOME!

[Ocean1]

I don't hate Buell. They make my half fucked 27 year old tourer, look positively AWESOME!

Mate, if that's only half fucked you better put it in a bag to finish the job.

[Drew]

Mate, if that's only half fucked you better put it in a bag to finish the job.
Na, heaps of life left in the old girl. Reckon it would have won the contest for most time spent on one wheel, on the way to Wanganui this year!

[Ocean1]

Na, heaps of life left in the old girl. Reckon it would have won the contest for most time spent on one wheel, on the way to Wanganui this year!

Doing the hillclimb on that this year?

[Drew]

Doing the hillclimb on that this year?Next year. Not sure if I'll take it over. Al' and I will be doing it on the sidecar, and we'd like to actually go fast.

If Al' is taking his solo over, I will too.

[Ocean1]

Next year. Not sure if I'll take it over. Al' and I will be doing it on the sidecar, and we'd like to actually go fast.

If Al' is taking his solo over, I will too.

Must have a look at this trike at some stage. Good luck with it.

[Drew]

Must have a look at this trike at some stage. Good luck with it.
You should let us build it in your much better tooled garage I reckon.

Milling machine, Tig, and lathe would be soooo fuckin handy to have on tap!

[Ocean1]

You should let us build it in your much better tooled garage I reckon.

Milling machine, Tig, and lathe would be soooo fuckin handy to have on tap!

Not that tooled up mate, still got a few things on the workshop shopping list.

But if you need anything done you can't manage let me know eh?

[AllanB]

Soooooo did you get your belleding brakes bleed?

[Drew]

Not that tooled up mate, still got a few things on the workshop shopping list.

But if you need anything done you can't manage let me know eh?Cheers bro, will do.

[DEATH_INC.]

Meh. More is always better.
Amateurs.....

275355

[DEATH_INC.]

Meh. More is always better.
Amateurs..... 12pots!

275356

[actungbaby]

Hi Guys,I,m having a real hard time getting my front brakes bled.
My brakes were dragging a little bit so I pulled the callipers apart ,cleaned them and when I bled them I couldnt get
decent pressure ,you could pull the lever back to the handlebars.
So I pulled em apart again and put in new seals, boots and new pads.
Spent 6 hours trying to get good pressure...
If I clamp off the hoses or even just 1 side just above the calliper...hey presto pressure .
If I clamp off hose from master cylinder....pressure.
I cant see it being a master cylinder problem.
I have bled many brake systems on cars and never had such problems.
I,d be ripping my hair out if it wasnt so short ,just got a number 3.
Hoping someone might have some clues for me
Thanks in advance
By the way its a gsx 1100f suzi

Join the club dude had this same problem with my vfr 750 i dont remember being that hard to do

Anyways when to local bike shop and he told me to keep going and to loosen banjo bolt of the top master cylider (where fuild is filled) to let trapped air there , i keep getting bubbles out the bleed hose, but strangest thing was i have tp pump the lever like 4 times with bleed nut closed then release to get fulid moving aghhh , 20 years ago sure was like what books say , pull lever just b4 u realse the fuild valve didnt work for me .
I ended up replacing the seals in the master , left the slave , still had few bubles but finally got okay pressure passed the wof brakes are strong enough, l cleaned the calibers and used rubber grease (little) on the pisten seals after getting them out fully this made them move isteed just sitting there as b4, my right rotor gets hotter than the left but am leaving it for know cause such pain in the bum to do.

[actungbaby]

Speed bleeders are teh shizz, I'll be buying some (thanks for the reminder)

I generally do it as Drew has said, I also move the brake spliiter around on my Kawasaki as it sometimes gets bubbles sitting in it :rolleyes: and the master... and the calipers.
Pricks of things

Ur got that right on my cbx 400 it was easy well maybe it wasint was so long ago

But that was just one disc system so maybe why. (mind you brakes where shit ) cast iron

Iboard ventaled indeed felt like sqweezing a block of wood modern brakes pads much better

[imdying]

Speed bleeders are a waste of money. Perfectly good bleeders come on every caliper. Keep the end of your bleeder hose submerged (make the hole in the lid of you jar slightly undersized to hold it in place) and you have all the advantages for none of the money.


btw I do not think of Buell owners as fashion victims, more anti-fashion victims. Getting the spinning weight as far away from the centre of the hub as possible is always awesome.

[gwigs]

Still fucking around with these brakes,I,m going to start buying brake fluid by the gallon.
I,ve tried all the different methods you guys have suggested plus things from other forums except a vacuum pump,cant afford one.
Tying the lever back to the bar overnight works but after a few minutes its back to mushy.
Had the callipers apart twice,put thread tape on the bleeder threads nothing seems to work.
if I clamp off the hose from the master cylinder I get a rock solid lever,if I clamp off either of
the calliper hoses I get a reasonable firm lever.
I really cant see it being the master cylinder but I,m thinking about putting a kit in it
but I really cant afford to just keep throwing money at it.
I,ve just splashed out and painted the tank and the fairings,would love to put the body work on so
I can see how it looks but not going to fit it till I have brakes ,not with all the brake fluid all over the show.
Really had a gutsfull of it....
Any how thanks for all the imput..

[Bikemad]

hey gwigs...........i have a nifty bleed pump thingy that might be of some help............have used it on multiple bikes and cars........don't lend tools as a rule but happy to pop round with it and help ya out for an hour or two............PM me if ya keen

[AllanB]

Sounds like a air leak somewhere .........

[Laava]

Tbh sounds like take it to the shop time and just get them to put their bleeding gear on it.

[Bikemad]

this is the gadget i use............. http://www.amazon.com/Mityvac-MV8000-Automotive-Test-Bleeding/dp/B00265M9SS

bought it at the old motomail 15 years ago.........probably the best $120 i have ever spent on tools...........works a treat

[_Shrek_]

Still fucking around with these brakes,I,m going to start buying brake fluid by the gallon.
I,ve tried all the different methods you guys have suggested plus things from other forums except a vacuum pump,cant afford one.
Tying the lever back to the bar overnight works but after a few minutes its back to mushy.
Had the callipers apart twice,put thread tape on the bleeder threads nothing seems to work.
if I clamp off the hose from the master cylinder I get a rock solid lever,if I clamp off either of
the calliper hoses I get a reasonable firm lever.
I really cant see it being the master cylinder but I,m thinking about putting a kit in it
but I really cant afford to just keep throwing money at it.
I,ve just splashed out and painted the tank and the fairings,would love to put the body work on so
I can see how it looks but not going to fit it till I have brakes ,not with all the brake fluid all over the show.
Really had a gutsfull of it....
Any how thanks for all the imput..

all I did with the XT600 after stripping & cleaning front calliper, was put a clear hose on the bleed nipple & in a bottle with some fluid to stop sucking air up the hose & just kept pumping the lever & filling the mc as it went down untill the line had no air, have had no probs since

[sugilite]

I had the same issue with one of my race bikes. Brakes were awesome when the overnight tie down system was used, then soon as I started using them, they went away within 2 to 3 laps, or less. I know this sounds weird, but it turned out to be warped calipers. (I also have a file cabinet draw filled with warped discs from the same bike, I may have been a bit hard on them. :lol:)

[gwigs]

hey gwigs...........i have a nifty bleed pump thingy that might be of some help............have used it on multiple bikes and cars........don't lend tools as a rule but happy to pop round with it and help ya out for an hour or two............PM me if ya keen

Thanks for the offer Bikemad ,my sons mate is going to come around with his pump sometime soon. Cheers.:2thumbsup

[madandy]

With a simple bottle and clear hose on the bleed nipple I've used the same, left hand on spanner to lossen n tighten the nipple while right hand pumps brake lever on all my bikes: RF400, YZF600R, GSXR750, 900SS and just done the VTR1000f plus a mates ZXR400. Made sure the resevior was at its highest by turning the handlebars accordingly and never let the fluid level drop too low. They each had either Nissin, Brembo and Tockico brakes and all were straight forward to do. There must be something wrong with your technique or more likely the hardware...it must be very frustrating!

Good luck with the pump!

[gwigs]

Well my brakes are still crap but I have at least pinpointed the problem.
A mate of my sons came around with a vacuum bleeder and out of 4 bleed nipples
one just kept on sucking air so I know its a leaking piston or seal and
better still I know which one......so at least I,m not running around in circles....
Thanks for all the advice...:niceone:
Nice bit of kit the vacuum bleeder,ran off my compressor,easy to bleed and no mess..

[Bikemad]

have you found evidence of brake fluid on the back of the disc pad on the caliper in question........should be there if the seals are shot i would have thought .....did you take the nipple right out when using ya gadget....if not are you sure its not just sucking air past the nipple thread.......i fell for that one first time round using similar gadget

[erik]

Did you get it sorted?
Something I tried recently that seemed to work was to remove the callipers and hold them so the banjo bolts are at the highest point, tap the callipers and lines etc (in the hope of getting any air bubbles to rise to the top), then push the pistons back into the callipers to force the fluid and hopefully any bubbles back through the lines to the master cylinder/reservoir at the top.
You have to be a bit careful to make sure the reservoir doesn't overflow when you push the pistons all back into the callipers. When I did it I left the pads in the callipers and used a piece of about 4mm x 20mm steel with rounded edges which I could twist between the pads to push the pistons back.

[gwigs]

Turned out I had some light pitting on on the of the pistons,I have ordered new ones from the States but they are back order from Japan
So I,m still waitng for them to be sent.Really annoying as I have painted the bike and fixed all its faults but with no brakes all I can do is wait.:crybaby:

[Premature Accelerato]

Any up date on this problem so far, did the new parts solve the problem. Am experiencing a similar problem with six pot calipers on the gisxer.

[gwigs]

Still waiting for my new pistons....four fucking months and the bastards wont even reply to my emails...:angry2:
I,m getting to the stage of joining every biker forum I can and slagging them off...
Four months in this day and age...:brick:

[Laava]

I assume you have paid for them? Can you get your money back?
Surely they are avail from elsewhere? Wemoto.com?
http://www.partsnmore.com/parts/suzuki/gsx1100f/?filters%5Bfitting%5D=custom these guys have them listed at $23ea. But is this who you ordered from?
Have you priced up getting them made at a hydraulics shop? Might be the go esp if you have eight to replace?

[gwigs]

I assume you have paid for them? Can you get your money back?
Surely they are avail from elsewhere? Wemoto.com?

Yeah they,re all paid for but its hard to get my noney back when they dont reply to emails...besides havent got any more money to
buy them elsewhere...I have spent nearly a grand on parts with this outfit before and have had no probs till now..

[Laava]

Bummer, hope it works out real soon dude.
Worth a phone call?

[gwigs]

Bummer, hope it works out real soon dude.
Worth a phone call?

Yeah you,re right might have to do that..

[Premature Accelerato]

Four months, you could have hand made the bits yourself in that time. So, was the diagnosis that air was getting in around the pitting even though you were not appearing to loose brake fluid. On my gixser. after having bleed the brakes, after about 40 laps of Manfeild, my brake lever is touching the bars. Re bleed and start again. And again. And again.

[gwigs]

Four months, you could have hand made the bits yourself in that time. So, was the diagnosis that air was getting in around the pitting even though you were not appearing to loose brake fluid. On my gixser. after having bleed the brakes, after about 40 laps of Manfeild, my brake lever is touching the bars. Re bleed and start again. And again. And again.

Been there done that trust me I know it was a pitted piston...used a vacuum bleeder on it ..pointed to the exact piston , though other pistons had minor pittting..only 2 pistons per calliper each with its own bleeder wasnt hard to pin point it...one piston with pitting in line with seals..:weep:

[imdying]

It's not leaking air in past pits on a piston :laugh:

[pete376403]

Seems odd that atmospheric pressure air can get in but hydraulic fluid at far greater pressure doesn't get out.

[gammaguy]

Air is less dense than hydraulic fluid

[Premature Accelerato]

I want to have a go at checking the integrity of my seals and pistons. Has anyone tried removing a caliper, modifying a bleed nipple to accommodate an air line and then pressurising the caliper (with packers to simulate the thickness of pads and rotor in place) while submersing the whole thing in water. Any ideas as to the air pressure that would need to be used?

[Drew]

I want to have a go at checking the integrity of my seals and pistons. Has anyone tried removing a caliper, modifying a bleed nipple to accommodate an air line and then pressurising the caliper (with packers to simulate the thickness of pads and rotor in place) while submersing the whole thing in water. Any ideas as to the air pressure that would need to be used?

To what end? If fluid doesn't come out of there, they seal fine when pressurised on the inside.

Air getting into the system will be happening when the lever is released, and there less resistance for air to go past the seals, than the pistons pulling back.

[imdying]

I want to have a go at checking the integrity of my seals and pistons. Has anyone tried removing a caliper, modifying a bleed nipple to accommodate an air line and then pressurising the caliper (with packers to simulate the thickness of pads and rotor in place) while submersing the whole thing in water. Any ideas as to the air pressure that would need to be used?Yes, and we use around 4500psi. Waste of time though... if fluid doesn't leak out, then it's fine.

[Drew]

if fluid doesn't leak out, then it's fine.I'm not convinced on this just yet.

Used to think the same, but then I started to consider why motocross bikes have air bleeders on the forks. They mostly aren't leaking fluid, but they all need to let the air out of the forks after a race.

[imdying]

I'm not convinced on this just yet.

Used to think the same, but then I started to consider why motocross bikes have air bleeders on the forks. They mostly aren't leaking fluid, but they all need to let the air out of the forks after a race.Probably should note, they're tested with fluid at 4500psi, not air. But either way, it doesn't actually matter if you're convinced or not.

[bogan]

I'm not convinced on this just yet.

Used to think the same, but then I started to consider why motocross bikes have air bleeders on the forks. They mostly aren't leaking fluid, but they all need to let the air out of the forks after a race.

Are they actually bleeders? I though they were used to set the base pressure. You'll be able to 'bleed' air out after a race cos the oil/air will have got hot during. And bleeding before a race may well be just letting air back in since it has cooled down and lost pressure from the last 'hot' bleed.


Probably should note, they're tested with fluid at 4500psi, not air. But either way, it doesn't actually matter if you're convinced or not.

Yeh pressure testing with gas is generally a bad idea...

[Drew]

Are they actually bleeders? I though they were used to set the base pressure. You'll be able to 'bleed' air out after a race cos the oil/air will have got hot during. And bleeding before a race may well be just letting air back in since it has cooled down and lost pressure from the last 'hot' bleed.

Air preloading went out with damper rods bro.

Gas forks these days, are sealed cartridges to reduce cavitation under and above the piston. The extra spring effect is a negative by product, but the lesser of two evils. I think the new systems might not even have said spring effect, but I don't know for sure.

[Drew]

it doesn't actually matter if you're convinced or not.I was implying (but maybe it was too subtle for your superior self), that I would like to know why you think air cannot be dragged back past the seals, rather than the piston return. I used motoX forks as an example of this happening in other applications.

Clearly you're too clever to waste your time for the likes of me though, and would rather be condescending instead.

Jog on.;)

[imdying]

I was implying (but maybe it was too subtle for your superior self), that I would like to know why you think air cannot be dragged back past the seals, rather than the piston return. I used motoX forks as an example of this happening in other applications.

Clearly you're too clever to waste your time for the likes of me though, and would rather be condescending instead.

Jog on.;)

<img src="http://1.bp.blogspot.com/_tOJ0BeW5vXw/TPMTu5Ih5KI/AAAAAAAAAAM/DJp86ZUDrfg/s1600/Butthurt.PNG" />

I'm not sure what you expected... you used a completely unrelated example; completely difference stroke, completely different seal type, completely different application. If you don't want to be dismissed as a muppet, try applying some critical thinking of your own instead of blurting the first thing out that your two brain cells come up with. I knew exactly what your were implying, it just wasn't worth my time ;)

[FROSTY]

gwigs. Has anyone suggested having a look at the brake lines? I wonder if a big part of your problem is the brake lines swelling when you apply pressure

[gwigs]

gwigs. Has anyone suggested having a look at the brake lines? I wonder if a big part of your problem is the brake lines swelling when you apply pressure

Well after waiting for months for new calliper pistons I find out from the parts people that Suzuki dont make them anymore.
So I tracked down some second hand Callipers...brakes still no good ...put in mastercylinder kit...brakes still no good..
Put new braided lines on two days ago and yipee I got brakes again...so you are right on the mark there:niceone: