are these the right ones ?

https://www.pro-bolt.com/stainless-steel-b...sbn10-4z1/

£20 quid for a pack of four including vat

Stainless Steel Bleed Nipple M10 Front Brake Caliper Pack x4 (SSBN10-4Z1)

Material: Stainless Steel
Product Type: Brake / Caliper
Thread Diameter: 10mm
Thread Pitch: 1.00mm
Length: 29mm
Socket Size: 11mm

If the nipple has corroded inside that would suggest the brake fluid maintenance has been overlooked a few times. Christian.


Current Cars
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Steel/Alloy thread interfaces will cause galvanic corrosion. Stainless steel won't be any better. 2012 TDV8 Vogue (L322)

Caesium wrote:

If the nipple has corroded inside that would suggest the brake fluid maintenance has been overlooked a few times.

maybe, but let me get the frigging M10 bolts out first

when I do get them out I will be looking out for some rubber covers to give them a little more protection when I put new ones in

JayGee wrote:

Steel/Alloy thread interfaces will cause galvanic corrosion. Stainless steel won't be any better.

and I guess Titanium is no better ??

I will need to buy 4 x new nipple bolts anyway, so are you saying that there is no material that will help slow down the corrosion, if so this is really awful design on the part of JLR and Brembo

Caesium wrote:

If the nipple has corroded inside that would suggest the brake fluid maintenance has been overlooked a few times.

True, in the prescence of water but there shouldn’t be any water in your brake fluid, if changed regularly.
There’s no option of alloy nipples of course, they’d just snap like carrots

I sparingly use copper grease on mine, knowing that the thread is outboard of the nipple seat, so fluid and grease should never mingle other than when bleeding, when the flow is away from the calipers anyway.

EDIT: Sorry it wasn’t copper grease, I used PTFE tape! (on new nipples/new brakes).
I don’t think its a big deal, if used sparingly, anything that provides a barrier will prevent corrosion, the threads
are outboard of the brake fluid, so contamination of fluid is highly unlikely in operation, only when bleeding when the
old fluid is flushing any particles out of the caliper. “If it ain’t broke, don’t fix it” -where’s the fun in that?

Covers won't make any difference - it's the steel of the nipples interfacing with the alloy of the callipers that causes the problem. Maybe look for some lightweight 'racing' nipples. Some alloys of Aluminium are very strong and are used in aerospace applications so well up to the job. Red Rubber grease is safe to use on the threads as it's designed to contact brake fluid. 2012 TDV8 Vogue (L322)

Last edited by JayGee on 24th Oct 2022 3:31pm. Edited 1 time in total

these Titanium ones sound the answer - anyone used them - here is the sales blurb

-----------------------------------------
Unrivalled anti-corrosion resistance. Titanium takes over 10 years to tarnish the surface and over 40 years to show microscopic signs of corrosion.

Twice as strong as stainless steel. We only use grade 5 6Al-4V titanium in our bleed nipples. With its high titanium content along with small amounts of aluminium and vanadium grade 5 6Al-4V titanium merges its superior anti-corrosion properties with high tensile strength giving you the strongest and most durable bleed nipples on the market.

Lightweight. Almost half the weight of stainless steel and twice as strong.

No more snapped bleed nipples. Saving yourself £100s in the future. Steel bleed nipples will always rust and seize. Its only a matter of time. Once seized they are prone to snapping when the brakes are bled.

Best case scenario, the snapped bleed nipple can be extracted
Worst case scenario, a new caliper is needed costing many hundreds

Our titanium 6Al-4V bleed nipples will never rust or seize
---------------------------------------------------------------------------------------------

JayGee wrote:

Steel/Alloy thread interfaces will cause galvanic corrosion. Stainless steel won't be any better.

D3 Jon, it's worse than that, it's steel, stainless or otherwise into alloy..!!

Gremlin500 wrote:

I sparingly use copper grease on mine,

You shouldn't use copper grease on alloy callipers, it's just adding another metal into the mix and will promote corrosion...

Don't know if this is compatible with brake fluid but seeing as fluid only tends to flow out of a bleed nipple I'd use some of this... Used it on the boat and it is good...

https://www.force4.co.uk/item/Harken/Tef-G...-Paste/CM8 Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Thanks, good point and just realised that myself Pete.

Was thinking it was the (steel) rears in question as that's what I've just been working on on my 4.4 TDV8 - but yes, of course, the front's have steel nipples (an alloy in itself) in a more alloy, er.. alloy if that makes sense - arghhh!

Jon 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

See my update above….. “If it ain’t broke, don’t fix it” -where’s the fun in that?

Gremlin500 wrote:

See my update above…..

@D3Jon:

Yeah, there is a lot of BS on the internet about brake fliud “dissolving PTFE tape” from armchair “experts” however despite looking up each ingredient of DOT4 and searching “compatibility with PTFE” one by one, I was unable to find any support for this theory, or any scholarly articles in support thereof, so until anyone tells me otherwise with supporting references, I’ll continue to do so, but all please make your own minds up, thanks. Important to say, the PTFE is there only on the threads and not there to seal, just to be an electrical insulator to any possible galvanic action as a barrier between the dissimilar metals.. One of the best well-documented properties of PTFE is that is an excellent electrical insulator.

As for “stainless” steel? Read this:-

https:/www.boatus.com/expert-advice/expert-advice-archive/2016/august//not-so-stainless-steel

 “If it ain’t broke, don’t fix it” -where’s the fun in that?

Goodridge stainless steel braided flexible brake hoses have PTFE liners. 2012 TDV8 Vogue (L322)