Bleed valve woes...

[magicmonkey]

So I've finally got the ZXR running well, the engine is top notch now :) I decided that it'd be a good idea to replace the brake fluid as its been in there at least 3 years so it needed to be done. When I unscrewed the bleed valve on the front left calliper it stripped the thread from the calliper, rather than the bleed valve, meaning that the calliper is pretty much useless now. Just wondering, is there some sort of magic trick I can use to sort that out or is it time to try and find a replacement?

Also, anyone got a spare calliper knocking around :p

[FJRider]

So I've finally got the ZXR running well, the engine is top notch now :) I decided that it'd be a good idea to replace the brake fluid as its been in there at least 3 years so it needed to be done. When I unscrewed the bleed valve on the front left calliper it stripped the thread from the calliper, rather than the bleed valve, meaning that the calliper is pretty much useless now. Just wondering, is there some sort of magic trick I can use to sort that out or is it time to try and find a replacement?

Also, anyone got a spare calliper knocking around :p

at least you have a hole ... they often snap off.

Either drill and re-tap a new thread with next size thread and replace with next size bleeder with the thread of that size ... or a heli-coil and use a new bleeder of the original size thread.

[magicmonkey]

at least you have a hole ... they often snap off.

Either drill and re-tap a new thread with next size thread and replace with next size bleeder with the thread of that size ... or a heli-coil and use a new bleeder of the original size thread.

is a helicoil ok to use in the brake system? I know the bleed valve isn't under that much pressure but I'm always wary of brakes ...

[Drew]

Bigger hole and bleed nipple, or helicoil for sure.

These are brakes though remember! The calliper needs to be TOTALLY free of swarf once the drilling and tapping is done, or the shit could very well hit the fan really quickly.

[Drew]

is a helicoil ok to use in the brake system? I know the bleed valve isn't under that much pressure but I'm always wary of brakes ...
They helicoil spark plug threads, what do you reckon?

[FJRider]

Bigger hole and bleed nipple, or helicoil for sure.

These are brakes though remember! The calliper needs to be TOTALLY free of swarf once the drilling and tapping is done, or the shit could very well hit the fan really quickly.

NOT the job you do with it still on the bike .. :blink:

[magicmonkey]

ok, I've never used a helicoil before but doesn't that involve drilling and tapping?

[schrodingers cat]

Depending on the material around the nipple there are options

1. Since a nipple relies on a tapered seat they don't need to be terribly tight (60"/lb for a 3/8 thread - about 5ft/lb) Most motorcycle nipples are about a M6 thread
Therefore you can helicoil the calliper, Ensure the helicoil is fitted square!

2. Find a larger thread size nipple and tap accordingly

3.Wilwood produce a replacement nipple. It consists of a brass insert (1/8" BSP) with a 1/4 UNF nipple in it. Most (car) speed shops will know what you're talking about

(Before any predants jump on me, I've guessed at the thread sizes but they are there or there-abouts)

Don't take it to a mechanic. Take it to a practical engineer/machinist/fitter

[schrodingers cat]

Bigger hole and bleed nipple, or helicoil for sure.

These are brakes though remember! The calliper needs to be TOTALLY free of swarf once the drilling and tapping is done, or the shit could very well hit the fan really quickly.

Fill the hole with vaseline or grease and bleed throughly when finished. Or if it is off the bike remove the piston and clean while you're there.

The tapered seat does the work NOT the thread

[magicmonkey]

Fill the hole with vaseline or grease and bleed throughly when finished. Or if it is off the bike remove the piston and clean while you're there.

The tapered seat does the work NOT the thread

well, I figure that it's going to need to come off the bike either way so I may as well just take it off today. One thing the manual doesn't say, and probably a really stupid question, but I assume I need to drain the fluid out before taking off the callipers right?

[schrodingers cat]

well, I figure that it's going to need to come off the bike either way so I may as well just take it off today. One thing the manual doesn't say, and probably a really stupid question, but I assume I need to drain the fluid out before taking off the callipers right?

Trust me. Take the calliper off and the fluid will find its way out:yes:

[magicmonkey]

Trust me. Take the calliper off and the fluid will find its way out:yes:

sweet, at least that's what I thought would happen :) time to find a metal bucket :)

[schrodingers cat]

Brake fluid is a bit corrosive so give everything a wipe down with a damp cloth

[FJRider]

Just remember the effect brake fluid has on paint ... :facepalm:

[T.W.R]

Don't f@#% around tapping out the nipple hole just get a replacement caliper from a wrecker :yes:
To effectively ensure there isn't any chance of swarf getting where it shouldn't be you'll have to split the caliper anyhow, and that's going to cost a set of seals along with the other expenses involved

[magicmonkey]

Don't f@#% around tapping out the nipple hole just get a replacement caliper from a wrecker :yes:
To effectively ensure there isn't any chance of swarf getting where it shouldn't be you'll have to split the caliper anyhow, and that's going to cost a set of seals along with the other expenses involved

well, I just popped down richards motorcycles to see if he could pop a helicoil in and he reckons it's a bad idea as they're near impossible to get right. He's on the lookout for a second hand calliper for me now so I figure that's the best way to go. Thanks for the advice guys :)

[Drew]

well, I just popped down richards motorcycles to see if he could pop a helicoil in and he reckons it's a bad idea as they're near impossible to get right. He's on the lookout for a second hand calliper for me now so I figure that's the best way to go. Thanks for the advice guys :)

Post a picture of the calliper. I have probably got one here.

[magicmonkey]

Post a picture of the calliper. I have probably got one here.

nice one :)

pic of 2 of them here:

223979

[schrodingers cat]

Don't f@#% around tapping out the nipple hole just get a replacement caliper from a wrecker :yes:
To effectively ensure there isn't any chance of swarf getting where it shouldn't be you'll have to split the caliper anyhow, and that's going to cost a set of seals along with the other expenses involved

I call bullshit. There are no seals that can be damaged by splitting the calliper.

As for the helicoil - I told you not to take it to a mechanic

It's not difficult to get it right if you you know what you're doing.

Another (secondhand) calliper is fine in theory until it does the same thing. What condition are the seals etc in the replacement.

Either way, once its fixed you'll be riding and happy

[T.W.R]

I call bullshit. There are no seals that can be damaged by splitting the calliper.

As for the helicoil - I told you not to take it to a mechanic

It's not difficult to get it right if you you know what you're doing.

Another (secondhand) calliper is fine in theory until it does the same thing. What condition are the seals etc in the replacement.

Either way, once its fixed you'll be riding and happy

And you've probably no idea of how many seals are in a 4 piston caliper either :facepalm:

[imdying]

at least you have a hole ... they often snap off.True.

Either drill and re-tap a new thread with next size thread and replace with next size bleeder with the thread of that size ... or a heli-coil and use a new bleeder of the original size thread.True.

Bigger hole and bleed nipple, or helicoil for sure.True.

These are brakes though remember! The calliper needs to be TOTALLY free of swarf once the drilling and tapping is done, or the shit could very well hit the fan really quickly.True!

They helicoil spark plug threads, what do you reckon?So true.

1. Since a nipple relies on a tapered seat they don't need to be terribly tight (60"/lb for a 3/8 thread - about 5ft/lb) Most motorcycle nipples are about a M6 thread
Therefore you can helicoil the calliper, Ensure the helicoil is fitted square!True.

2. Find a larger thread size nipple and tap accordingly

3.Wilwood produce a replacement nipple. It consists of a brass insert (1/8" BSP) with a 1/4 UNF nipple in it. Most (car) speed shops will know what you're talking aboutTrue, got those in stock.

(Before any predants jump on me, I've guessed at the thread sizes but they are there or there-abouts)Pretty sure that's right.

Don't take it to a mechanic. Take it to a practical engineer/machinist/fitterAlso true.

Fill the hole with vaseline or grease and bleed throughly when finished.Not a fan. Strip it and clean it. Do both.

The tapered seat does the work NOT the threadTrue.

Don't f@#% around tapping out the nipple hole just get a replacement caliper from a wrecker :yes:Old shit sitting around, might just buy another problem.

To effectively ensure there isn't any chance of swarf getting where it shouldn't be you'll have to split the caliper anyhow

that's going to cost a set of seals along with the other expenses involvedMaybe, but unlikely.

I just popped down richards motorcycles to see if he could pop a helicoil in and he reckons it's a bad idea as they're near impossible to get right.Next time try somewhere that knows what they're doing. For the most part, mechanics aren't engineers arseholes.

I call bullshit. There are no seals that can be damaged by splitting the calliper.The side to side channel will probably come out at the bottom of the piston bore, so whilst it's true that splitting them can't damage any seals, popping the piston and putting it back in carries a miniscule chance of damaging the piston seal.

As for the helicoil - I told you not to take it to a mechanic

It's not difficult to get it right if you you know what you're doing.Yup

Another (secondhand) calliper is fine in theory until it does the same thing. What condition are the seals etc in the replacement.

Either way, once its fixed you'll be riding and happyBascially, yup.

And you've probably no idea of how many seals are in a 4 piston caliper either :facepalm:Yup, it's scary stuff.... 5, maybe 6 :facepalm:

Plus 4 dust rings that don't seal shit.. oh, the horrors :blink:

Really, given your posts, and given his, I'd say you're the one a bit short on practical experience in this instance. If not, then you've spent ages doing it the wrong/hard way :msn-wink:

[Drew]

Hmmm, your callipers seem to be single sided. Only thing I've got that's close is a set of 400 impulse callipers but they are four pot opposed jobs.

Anyone know if they are the same?

[Katman]

Ensure the helicoil is fitted square!



This is the most important part. Drill the hole even fractionally off square and the tapered seat will not seal.

[Katman]

To effectively ensure there isn't any chance of swarf getting where it shouldn't be you'll have to split the caliper anyhow, and that's going to cost a set of seals along with the other expenses involved

I have stripped and cleaned countless calipers, including removing the seals and scraping the build up of shit from behind them, and never yet found the need to replace the seals.

[Drew]

I have stripped and cleaned countless calpiers, including removing the seals and scrapping the build up of shit from behind them, and never yet found the need to replace the seals.

Yep, got the run down on that from a guy that works at Wellington motorcycles just yesterday. They do heaps of brake servicing he reckons and never changes the seals.

[T.W.R]

Maybe, but unlikely.

That answers it right there :yes: the possibilty & non 100% guarantee dictates doing the job properly


The side to side channel will probably come out at the bottom of the piston bore, so whilst it's true that splitting them can't damage any seals, popping the piston and putting it back in carries a miniscule chance of damaging the piston seal.

So you'd re-fit gallery O-rings that have been permanently compressed & hardened due to heat dissipation :facepalm:
I'd rather risk miniscule damage to a fesh seal rather than one that's been in use & most likely swollen & worn :yes:




Really, given your posts, and given his, I'd say you're the one a bit short on practical experience in this instance. If not, then you've spent ages doing it the wrong/hard way :msn-wink:

There aren't short cuts to doing a job properly & you don't take chances or bush mechanic risks with important items


I have stripped and cleaned countless calipers, including removing the seals and scraping the build up of shit from behind them, and never yet found the need to replace the seals.

Keep playing with farm hacks & quads Knob juice

[imdying]

That answers it right there :yes: the possibilty & non 100% guarantee dictates doing the job properlyWhat, like your suggestion of fitting a caliper from a wrecker?

Both of those actions carry a certain amount of risk:

- One risks a cack hand nicking a seal. It is of course possible to slice a seal, but it's a risk you can mitigate by using a small flat head screw driver that has the end filled smooth. After few dozen calipers a week for a few years, I can tell you that that will bring the risk down to less than one in a thousand, and 0.1% risk isn't bad IMHO, especially when weighed against the fact that the exact same damage could occur when fitting a new one.

- One risks when getting a second hand caliper, getting something with rusted calipers pistons/slides/bolts/bleeders etc. Risk of that... 50/50?

50% risk, or 0.1% risk... I know which one I would take.


So you'd re-fit gallery O-rings that have been permanently compressed & hardened due to heat dissipation :facepalm:You can use the facepalm smiley all you like, but real life experience shows us that your scare mongering is baseless. The seals are well able to handle the heat and compression, that's exactly what they're designed for.



I'd rather risk miniscule damage to a fesh seal rather than one that's been in use & most likely swollen & worn :yes:Most likely...? There you go again, talking out your arse using assumptions as your base instead of experience and facts.



There aren't short cuts to doing a job properly & you don't take chances or bush mechanic risks with important itemsWhich is why, for the safety of others, I would ask you not to touch brakes in the future :facepalm:

[T.W.R]

What, like your suggestion of fitting a caliper from a wrecker?

Both of those actions carry a certain amount of risk:

- One risks a cack hand nicking a seal. It is of course possible to slice a seal, but it's a risk you can mitigate by using a small flat head screw driver that has the end filled smooth. After few dozen calipers a week for a few years, I can tell you that that will bring the risk down to less than one in a thousand, and 0.1% risk isn't bad IMHO, especially when weighed against the fact that the exact same damage could occur when fitting a new one.

- One risks when getting a second hand caliper, getting something with rusted calipers pistons/slides/bolts/bleeders etc. Risk of that... 50/50?

50% risk, or 0.1% risk... I know which one I would take.

You can use the facepalm smiley all you like, but real life experience shows us that your scare mongering is baseless. The seals are well able to handle the heat and compression, that's exactly what they're designed for.


Most likely...? There you go again, talking out your arse using assumptions as your base instead of experience and facts.


Which is why, for the safety of others, I would ask you not to touch brakes in the future :facepalm:

It took you all of 20mins to make that reply....you're making assumptions yourself and blowing your almighty trumpet....another self indulged hero of the KB brotherhood of legends :finger:

[imdying]

It's a good things that Arkham cares, cause I sure as fuck don't.

<img src="http://2.bp.blogspot.com/_N5xixYcUNF8/TFLDCtArsyI/AAAAAAAAAEc/B7PbCz-AKmE/s640/SAndyVagina.jpg" />


Get email notifications fool.

[F5 Dave]

Now that is seriarse funny.


As an aside; I have replaced the outer dust seals once before after finding the twist in them was pulling the pistons back & making for excessive lever travel even after a complete strip/clean careful reassemble. Cured the issue. Hadn't seen that before though.

[schrodingers cat]

It's a good things that Arkham cares, cause I sure as fuck don't.



Never argue with an idiot. They pull you down to their level and beat you with their experience.

Nice work Mr:laugh:

[Drew]

Ya fuckion hoo. Kiwibiker once again turns a difference of opinion in to a shit fight.

The best workshop in Wellington when it comes to bikes, does not change the seals on a brake calliper service, even though they remove the pistons and seals.

There is no need as seals made for brake and clutch fluid are very different in composition to normal seals such as those in your forks. If there is no damage to the seal and they weren't leaking there's no reason to think that they might start if you are careful.

But keep going for the throat cos it's fuckin funny. I'll help....


Get fucked, you're wrong!!!

[magicmonkey]

well, all sorted, I've sourced a second hand calliper and asked the guy selling it to check all the threads and seals before sending it, apparently they're fine :)

Drew, thanks for looking for one :)

[FROSTY]

Suys just5 one thing that leapt out at me was someone suggestiong using grease or similar. I STRONGLY recommend not doing so or you WILL be replacing every rubber seal in the caliper at least if the stuff gets into them.
Also Not wanting to restart a flame war. I've seen and heard on several occasions the recommendation to replace all the "rubber" seals in a caliper after stripping them.
USUALLY in US racing circles. I though agree with Drew and Katman that if it aint broke don't fix it.