Caliper bleed nipples and locking wheel nuts

[BoxsterLL11]

Today I decided I would flush through the brake system fluid.
I did all the service items at the end of last year but decided to leave the brake fluid flush until the fine weather.
Two minor disasters occurred whilst doing so.

BLEED NIPPLES
I started at the nearside rear and found the nipples very very tight (system should have been flushed two and a half years ago, that last time I paid for a service so that was when the nipples should have been last eased off & tightened).
Outer one eventually freed but the inner one sheared off before any movement.
From then on I removed the captive bleed nipple caps and soaked with PlusGas before attempting to back off the nipples.
With great care and gently applied force I eventually got all the others to back off but they were all very tight and could have sheared if too much force was applied too quickly.
I think the rubber loop of the captive caps do not help as they retain water at the top of the threads beneath the 11mm hex flats.
QUESTION ONE - does anyone know the thread size and thread length of the bleed nipples?
On my Mtsubishi FTO I have replaced the mild steel nipples with stainless steel ones so the threads will never corroded and seize into the caliper with the risk of shearing off.
At the moment I do not intend to do anything with the sheared off nipple, it does not appear to have moved before it sheared and is not leaking.
Bit of a pain I would imagine to remove.

LOCKING WHEEL NUTS
Obviously I had to take the wheels off to gain access to flush the brake fluid.
My OE locking wheel nut key failed about six months ago so I bought a new one from Porsche.
That one today is on the verge of failure.
I take my wheels off 2-3 times a year to fully clean & wax but since I have bought the new wheel key, today was only the second time I have used it.
So am now looking to replace the OE locking wheel nuts/key with an aftermarket set that can withstand the normal "run-o-the-mill" forces required to take the wheels off and put back on, which obviously the Porsche design of lug/key cannot.
QUESTION TWO - can anyone recommend some aftermarket locking wheel lugs.

 

[Timrice]

Just be wary using stainless steel nipples as you can still get electrolytic corrosion with it.

 

[Motorhead]

Keith,

I think the bleed nipples probably are the standard Brembo size M10 x 1.0. I’m not surprised that you had problems removing the nipples - especially the inner ones - because I doubt that most techs (Porsche Centre included) won’t bother to release both to bleed the brakes. Although - as Tim points out - electrolytic corrosion can still occur, the SS nipples shouldn’t snap when you’re removing them, although you could strip the thread more easily. A release compound should help.

Removing the sheared nipple could be challenging without removing the calliper, although with care you may be able to drill/use an extractor tool in-situ.

I know what you mean about the "chocolate” wheel nut key - very poor quality! I can’t recommend an alternative, but I’m sure that there are plenty out there with more robust steel keys.

Jeff

 

[Mike1960]

Hi,
The standard size for Brembo is usually M10 and 30mm in length.

I replaced mine with Stainless Steel and they have been fine. Probably because I do the bleeding myself and don’t over tighten them.
I am with you about the locking wheel nut tool and their quality. At some point I am going to get rid of them altogether and just have wheel nuts.
Having to keep getting the adaptor out every time I take a wheel off is becoming tiresome.
Good luck with the snapped bleed nipple.

 

[Motorhead]

I agree with you Mike about replacing the locking nuts with standard nuts, especially if the car is garaged. They’re a bit of a waste of time these days when battery-powered impact guns and locking wheel nut removers are readily available to the criminal fraternity.

Jeff

 

[BoxsterLL11]

Thanks for your replies.
I too thought about ditching the locking wheel nuts and just have five standard ones per wheel.

When you have two dissimilar metals in contact with each other in a corrosive environment the less noble corrodes quicker, this is the electrolytic action.
This is why ships used to have a number of sacrificial anodes bolted to the hull in the form of lumps of zinc which would corroded more quickly in preference to the steel hull. The sacrificial anodes would then get replaced at each drydock.
Now when fitting stainless nipples, the less noble metal will be the caliper housing but there is a larger volume of that compared to the stainless nipple so any corrosion of the caliper would, I believe, be negligible. And is not the corrosion of the nipple itself directly that causes the issue, its the corrosion of threads at the point of contact and the exposed section beneath the captive bleed cap which weakens the nipple itself, then when trying to undo the seized threads causes too much torque to be placed on the section of the nipple that has corroded beneath the rubber ring and its there that the nipple shears.
I have had stainless nipples on the FTO for over 5 years, threads lightly coated in copper-slip when fitted and I have not had any issues since.
Don't quite see the purpose of the inner bleed nipple when the furtherest highest point at each corner is the outer nipple.
Suspect some air can get trapped on the caliper inner housing if the system is completely drained.

Providing the sheared off nipple doesn't leak, as its corroded in place, think I will leave well alone until I have a reason for removing the caliper from the car.

I will search the web for alternative locking nuts and let everyone know what I find unless someone else comes up with a reco.

 

[BoxsterLL11]

https://www.pro-bolt.com/stainless-steel-bleed-nipple-m10x1-00mm-pack-x4-ssbn10-4/

This is where I have bought the stainless nipples before.

 

[Mike1960]

Hi BoxsterLL11, I got my bleed nipples from a company called ‘Big Red’ which is just around the corner from me. Similar cost.
I have always thought that, as you have done, with a bit of copper slip, don’t over tighten, and eased every couple of years, they should have a longer life than me.

 

[BoxsterLL11]

Have ordered a set of these
https://www.design911.co.uk/fu/prod126413/Locking-Wheels-Bolt-Kit--and7mm-longer--DesignTek/

Wouldn't mind fitting a set of these though !!!
https://www.design911.co....-996-997--PACK-OF-20-/

 

[BoxsterLL11]

Have fitted some stainless nipples to the caliper outer nipples.

 

[BoxsterLL11]

And pic of the offending sheared brake nipple.
Have given it another soak in PlusGas but at present just leaving it alone.

 

[911hillclimber]

Just a quick question please:
Ref wheel nuts.
I hate the locking nuts on my 987.2 and they always feel they will break undoing or tightening.

Were these nuts used by Porsche when the cars were new?
If so, if you replace with ordinary nuts and the wheels are stolen, will this invalidate the insurance claim?

As to the broken nipple, a real removing tool is the only thing to trust if it will grip (stud extraction tool), doubt WD40 etc will do anything.

 

[Motorhead]

Graham,

Just to answer your question: yes it’s the original fitment, and it’s the "chocolate” key rather than the actual bolt which is the problem. I think that it’s aluminium and so isn’t particularly durable and is prone to damage if the tyre monkeys have been at it with their high-speed windy guns.

I think that key replacements are available from the dealerships … there’s a number stamped on it. If yours is feeling a bit worn it would be a good idea to order a replacement. At least it’ll be cheaper than buying a replacement set of locking wheel bolts.

Jeff

 

[BoxsterLL11]

My original Porsche locking wheel nut key failed last November.
Bought a new from my local Porsche centre.
Used in November 2020.
Used it again last weekend when the new one started to fail.
So not impressed, hence my decision to change to a superior aftermarket product.

I had a 987.2 before my 981 and bought a full set of DesignTek standard/locking wheel lugs so knew what I was getting.
Have to admit, wheels now look a little odd with one shiny locking wheel bolt and four dull black standard ones so I can see myself buying a full set of the standard ones soon.
The OE wheel nut keys do have their "unique" pattern number on the face of the key.
But mine only lasted a two cycles of 4 wheel removals, not using a windy gun either.
They are about £10 a go but do you want to run the risk of damaging a tightened wheel lug making it difficult to remove or destroying the wheel nut key when a replacement is not quickly available.
Of course, you could always buy two, keep one as new as a stand-by should the used one fail.
But in my opinion its a poor design and even worse manufactured quality.
Sorry, but I would rather pay for something of quality than be a cheap-skate and then never knowing when the wheel key might be about to fail.
I have not been a Porsche owner for long but would have expected better from them for something as simple as a locking wheel nut key.

And as to the sheared nipple, I am not using WD40.
PlusGas is far superior to WD40.
It was PlusGas I used to free up all the other brake nipples last week which did not shear.
I will apply a little PlusGas every time I remove the wheel.
As yet, I have no intention of trying to remove the sheared nipple for fear of damaging a perfectly healthy caliper.
There is a method of removing sheared bleed nipples, as yet I do not need to try but when/if the time comes, my regular application of PlusGas may well make the job a little easier.
I suspect WD40 would have little effect at all.

 

[Motorhead]

Could’t agree more about your adverse comments about shoddy Porsche design and materials Keith. Unfortunately other examples are often quoted here and elsewhere, exhaust fittings being one of them.

Rather sadly, Porsche isn’t immune from "value engineering” its products.

Jeff

 

[BoxsterLL11]

It does amaze me Jeff that a manufacturer such as Porsche, do have cost over quality in their mindset in certain aspects of the car.
As you say the exhaust, I have already replaced exhaust clamps for Mikalor stainless clamps and dodgy mild steel flange bolts prone to severe corrosion for stainless bolts.
I had absolutely no intention of doing any work on the 981 when I bought it.
But as a mechanical engineer of 40 years working experience and with the guidance of others on this forum, there were certain jobs on the car I could not turn a blind eye to and thought "why pay someone else to do it".
Obviously, if a major problem arises, I am past my best to sort it but these minor issues that keep arising if I can I will attempt.

This is a quick list of what I have had to sort so far in 4 years of ownership :-
1. faulty alarm unit (beside battery) - corroded circuit board
2. lost AC gas, pin-holed condenser - new condensers & dryer fitted, cost less than £300 including re-gas
3. fitted plastic mesh in bumper openings to help prevent above future problems.
4. stainless bolts fitted to exhaust flange post cat
5. OE exhaust clamps replaced with Mikalor ones
6. drivers door speaker replaced - water got past glass seal and speaker failed
7. brake bleed nipples
8. small stones trapped in fan shrouds which can prevent rad/ac fans from operating - check these every time I remove wheels for cleaning
9. check roof drains are clear - my car had major issues with this before I bought the car
10. brake pedal bush replaced under warranty - known fault but no recall, causes pedal to not fully return and ECU's flash up several alarms. Only came to notice when I had heater full blast to footwell on a cold sunny winters day with roof down

I have to say that the car is fantastic to drive and get a thrill every time I get in it.
But it is a shame that these small minor issues need sorting every so often.
But suppose I am thankful that they are just minor issues and that I can sort them.

 

[911hillclimber]

Totally agree with the above.
My 987.2/2009 has had almost the very same list but 2 x AOS's, 5 front hoses in the cooling system and other silly things, plus 2 nasty RUST eruptions in the sills(!)

A friend bought some time ago an old 2.5 986. Very very low miles and it was perfect for 2 years, nothing went wrong.
On the strength of that bought a new 981, and after 5 years has a sting of issues some expensive. He thought he was buying into a quality brand and product. Now thinking of a new BMW Z4.

Easy to loose a customer, hard to keep one.

 

[rich mich]

i think the best way to get that snapped nipple out would be to drill and tap a thread in it then screw a bolt into it with 2 nuts ,tighten nuts down on to nipple one at a time then put a spanner on top of bolt and undo nipple, you could also try a screw extractor on it ,or a left hand drill.