Warped brake discs

[Emil]

1 hour ago, Gerrycan said:

 

Are you saying the (impressively named) EBC Ultimax pads were less grippy than OEM pads so that the rear drums worked more which resulted in better overall braking performance?

 

Were you experiencing brake judder with the original pads?

 

I'd say better brake distribution. 

 

I changed brake pads after 5000km because they were too grippy. Before they ruin the discs.

[Chris GB]

For reasons I've gone into extensively elsewhere, I believe this to be a problem with the hub drive flange design.

[Emil]

How could it be when it's fixed by changing the discs? 

[Chris GB]

It's well known that many cases of uneven brake torque / warped discs are caused by issues with the hub. Given the system's sensitivity to having wheels removed and replaced, it's the most likely cause. I'm in the position to analyse the problem over 195,000 miles in Citigos. Do some research for in depth explanations.

[Emil]

I always use torque wrench when I change wheels. Twice a year. Still I have warped discs.

 

I don't have to do any research. 

[Chris GB]

The only way I found to keep them flat was to progressively torque up the bolts on flawlessly clean hubs. I started at 30lb/ft and increased incrementally up to specified torque in small steps. The setup worked fine with no hint of wobble or judder for 28,000 miles. Shortly after a service where the wheels where removed and put back on with a torque wrench, the usual wobble started. If the setup is that sensitive to the way the bolts are tightened, it points to hub drive flange distortion. That the problem gets progressively worse with wear and eventually cures itself with enough disk wear, again pointing to hub distortion, it's a fair bet that the hub is the issue.

 

Really, you do need to do your research. There's so many factors that can cause these problems. I spent 12 years doing quality assurance and research in the automotive sector, much of it investigating stuff that went wrong on cars. If it taught me anything, it's that the numerous causes of stuff going wrong are seldom as obvious as you'd think.

[Rooted]

Those that had warped discs on cars that never had the wheels off since the UpMiiCitigo left the factory will just be one of those things, 

or were the wheels over tightened at the Production or at the PDI?

[Chris GB]

7 minutes ago, Offski said:

Those that had warped discs on cars that never had the wheels off since the UpMiiCitigo left the factory will just be one of those things, 

or were the wheels over tightened at the Production or at the PDI?

My first one was like that. Warpage started to become noticeable from about 3000 miles. I don't think it's the torque level, more the way they get to the torque. Second one was almost fine until wheels removed at service.

 

I've fixed the problem now. Bought a Suzuki Swift!

[Rooted]

Did the VW Group addressed the issue in components or the design of the brake disks recently or is the problem still happening with cars built in the last year or so?

 

Other than maybe on the Up GTI.

[Emil]

9 hours ago, Chris GB said:

 

 

Really, you do need to do your research. There's so many factors that can cause these problems. I spent 12 years doing quality assurance and research in the automotive sector, much of it investigating stuff that went wrong on cars. If it taught me anything, it's that the numerous causes of stuff going wrong are seldom as obvious as you'd think.

 

 

Next you are telling me about hot spots?

 

Ford says in their workshop manual that if you don't tighten wheel nuts with torque wrench you'll get warped discs. This way they don't have to give discs under warranty as people never use torque wrench. That's how I see it. 

 

Edit: By the way "Chris GB". I bet you didn't use OEM pads. Am I right? 

 

Because OEM pads are the culprit here. 

Edited 25 April, 2018 by Emil

[Rooted]

Life is just so simple!

 

Obviously every new Up!MiiCitigo leaves the factory fitted with OEM Brake pads, so what makes the difference as to which vehicles get warped discs and which do not?

Who are the different manufacturers / suppliers of Up!mIICitigo brake pads?

[Chris GB]

1 hour ago, Emil said:

 

 

Next you are telling me about hot spots?

 

Ford says in their workshop manual that if you don't tighten wheel nuts with torque wrench you'll get warped discs. This way they don't have to give discs under warranty as people never use torque wrench. That's how I see it. 

 

Edit: By the way "Chris GB". I bet you didn't use OEM pads. Am I right? 

 

Because OEM pads are the culprit here. 

Hot spots are a different issue. I'm not going to tell you about them because you need to do some proper research and I don't have time to be your researcher.

 

For contractual reasons, I cannot comment on Ford and warped discs. I can say that I have been directly involved with a major global car manufacturer with regard to finding out why new cars where coming away from showrooms with discs wobbling within a few miles, sometimes with just delivery mileage around 3 or 4 miles. Root cause was a significant change of alloy composition used in the discs.

 

Regarding pads, the only time I've not used OEM pads, I still had the issue. The uninterrupted 28,000 miles of smooth braking was on OEM pads and Apec disks. They then proceeded to exhibit the normal pattern of fault development after wheels where removed and refitted at service.  How much was that bet for?

 

Normally, if the fault is pad transfer, the problem arrives immediately after the transfer incident. In my experience of the Citigo, the problem develops gradually.

 

So discs that have exhibited the issue: OEM 2 sets, Apec 4 sets, Fremax 1 set.

 

Pads that have exhibited the issue: OEM 6 sets Breck 1 set.

 

Hubs that have exhibited the issue: OEM 2 sets.

 

When I had the Breck pads and Apec disks, the pads lasted a really long time. I'd get the problem, which would get progressively worse then progressively better to the point of curing itself, then progressively worse again after wheels removed and refitted for tyre change. The pattern of fault was identical to that experienced with OEM pads, but the Breck pads where very different to the OEM.

 

The only thing I didn't try was refacing the mating face of the alloys, which could be a contributing factor, but I've never had a DTI on the wheel faces, so can't say for sure.

[beezera10]

Sorry Emil, you seem to have a lot of opinions but very little evidence to back it up.  You may believe a lot of things, but not many of them are attested to by other people, it seems.

 

My Citigo has covered 29k on the original discs/pads.  Lots of town driving, sometimes hard on the brakes (even emergency stops), brakes being used all the time, etc, etc.  I do have a very slight 'warped disc feel' at very low speeds, but it's nothing to be concerned about.  Discs are a bit worn as they have a 2mm lip on the outer edge.  Will replace in the next couple of thousand miles with a full set of discs and pads.  Oh, and I almost always hold the brake on in traffic when the discs are hot - no problem there either.  Perhaps I'm not as particular as some so long as the car stops safely - which it does.

[KenONeill]

25 minutes ago, beezera10 said:

Sorry Emil, you seem to have a lot of opinions but very little evidence to back it up.

Take a wild guess why I blocked him!! 😉 

 

In your specific case, I think riding the brakes may be the issue, because that can bake pad residue onto the discs. Try not doing it for 6 months after you fit the new discs.

[Emil]

8 hours ago, beezera10 said:

Sorry Emil, you seem to have a lot of opinions but very little evidence to back it up.  You may believe a lot of things, but not many of them are attested to by other people, it seems.

 

 

Marvellous point of view. Absolutely the most useless reply so far. 

 

So far no one have given better answers for this issue than I have.

 

 

********

 

And our up! TSI still does not have these brake issues. It's from year 2017 and a bit over 30000km.

[beezera10]

Fair point Ken, certainly worth trying!

 

Emil, I don't know what planet you're living on but I struggle to believe it is Earth.  Pretty arrogant to assume you've given better answers when you clearly have not.

 

Thanks for all the sensible offerings - very useful.

 

 

[Emil]

Well. I have changed more than couple of discs for 3 Citigo I have owned. What could I know? 😄

[beezera10]

Not a lot, it would seem ..........😏

[Emil]

Tell me more. In what way I am wrong? 😄

[beezera10]

Well, certainly in the unpleasant and arrogant way you respond to posts.  You don't seem to have a good grasp of mechanics or mechanical processes, let alone commonsense.  This is why people have little regard for your comments.

 

I'm not going to waste any more of my time listening to you try to justify how clever you think you are.  Hot tip, brush up on your social skills and try to listen to people over the sound of your own voice.

 

If you wish to contribute, it would be helpful if you know what you are talking about and can contribute collaboratively, rather than try to argue your point above everybody else's.

 

All the best😉

[Emil]

Have you ever heard a thing called language barrier? I don't know how to say it nicely. There's some kind of issue how they produce brake discs. I don't know what it is. But somehow some little sisters does not have this issues. But some does. Doesn't matter how you say it. 

 

You have good discs. Be happy. Doesn't mean that all have good discs. Can you understand? 

[Breezy_Pete]

Are we certain that sister brands that use the same hubs don't suffer this issue?

When I look at the images of the hub design here http://www.vrakoviste-vw.cz/tehlice-s-nabojem-vpredu-vpravo-1s0407256d-1s0407615-vw-up

the feature that leaps off the page is the fact that they've replaced solid steel  with thinner steel and reinforcing ribs on the rear face  localised round the wheel bolt holes.

Looks like they may have overdone the lightening/material saving to me, at the cost of reduced rigidity.

 

Reading back a few posts I see that this fits with what Chris GB was saying almost 2 years ago.

Edited 15 January, 2020 by Wino

[Emil]

You see? How come I was wrong? 😄

[Breezy_Pete]

30 minutes ago, Emil said:

You see? How come I was wrong? 😄

You're saying it's the discs and/or the pads?

Hubs are neither of these..

Edited 15 January, 2020 by Wino

[Emil]

Yes. Hubs are not the issue, as when ever I change new discs the problem dissappear. Then it appears again in 5 to 15 thousand kilometers.