GT550 - The curse of a leaking brake bleed nipple

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Syd
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GT550 - The curse of a leaking brake bleed nipple

Post by Syd »

Went to get the front disc brake filled, bled and up and running and I a have a wee problem with the bleed nipple not sealing 100%. The caliper has been fully refurbished with new parts, powered coated and looks sweet, however the seal between the new bleed nipple and cone seat inside the caliper housing can't be right and there is a tiny leak around the thread when you apply and hold pressure on the brake lever. Apart from dismantling the caliper to fix the internal seat, does anyone know of a simple fix for this, apart from using Teflon thread tape which does'nt seem right for a brake line or is there a better product to use?
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Gary66
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by Gary66 »

Theres two types of PTFE tape, one for water and one for gas, both very cheap so may be worth a shot with either or
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BATTS
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by BATTS »

I had a similar issue and couldn't find anyone willing to recut the caliper, I tried these in the end "nipple therapy"!! you drill out the existing thread, rethread and insert a replacement nipple base, doesn't look to bad when done and far cheaper than sourcing a replacement caliper.
http://www.fraserbrowneng.co.uk/
caliper4a.jpg
Chris
76 GT750, 78 GT550, BMW K1600gtl
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martyducati

Re: GT550 - The curse of a leaking brake bleed nipple

Post by martyducati »

Are you using a stainless nipple? I've had that problem with them before,get a old nipple and rough it up with emery paper and try that
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Syd
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by Syd »

Thanks for the ideas. The nipple is not SS and is a new Suzuki one supplied by GT Reiner. Maybe roughing up the end with emery paper and using the tape will cure the problem.
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yeadon_m
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by yeadon_m »

I must say, that nipple therapy looks very good. They should have fitted those originally, these seats often get knackered. I too have had leakers and remarkably, PTFE tape seems to work.
But the seat is distorted and thats what stops a new and perfect nipple form sealing.
***Warning *** I haven't tried this, but one idea would be to abrade down the outer thread on an old nipple until it will just turn freely but not bite in the caliper hole thread. Now, put a dab of grinding past on the nipple seat, pop it in, attach a lightweight drill to the nipple top and gently spin it - checking often. If the caliper seat goes a smooth and uniform grey, with no dints, clean it all out, then try again. I might try this on a spare caliper I have (because the one on my 380B has an only-just-sealing nipple seat!!).
Cheers,
Mike
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Syd
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by Syd »

That sounds like a good idea. I want to fix the problem with everything in place and if I use grinding paste, if any of this went down the oil hole to the piston area, this should flush out when I pump a couple of cycles of brake fluid out of the brake system (fingers crossed)
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mizzytheman
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by mizzytheman »

Syd wrote:That sounds like a good idea. I want to fix the problem with everything in place and if I use grinding paste, if any of this went down the oil hole to the piston area, this should flush out when I pump a couple of cycles of brake fluid out of the brake system (fingers crossed)
PTFE is ok (plumbers tape for everything) but try some three bond on the threads. Works a treat.
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PaulD738
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by PaulD738 »

Just bin the complete front end and fit with a drum brake, no more leaking brake fluid and problem solved :roll: as an added bonus the brake will now work when it’s wet :lol:
They're rubbish them Jap bikes lad they won't last five minutes! you want to get yourself a nice Royal Enfield!
A quote from my old dad 8-)

I started out with nothing and I’ve got most of it left!
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Alan H
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Re: GT550 - The curse of a leaking brake bleed nipple

Post by Alan H »

For once I'm in agreement with Paul on tbat one.
Proof that four strokes are over complicated
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