Octavia "throws" a brake disc shield.

[alfalincs]

I'm not quite sure how to explain this, but having heard the odd graunch that we thought was a stone caught between the disc and the disc guard on the O/S front wheel, yesterday it got really bad to the point of thinking "something has come apart or dropped off" yesterday over 100 miles from home on the A38 just south of Burton on Trent. It was dark so I found a filling station forecourt and after telling them what I was up to I jacked up the car and removed the wheel in an out of the way (aka SAFE !!) spot.   The disc guard was still there, but flapping around as the centres had been ripped out of all three attachment points. I was able to slide the shield rearwards off the hub with no tools and that revealed some serious grinding marks where there had been contact with the revolving disc. I'm not aware of anybody having contacted anything that might have damaged the disc shield

 

I have never had the hub off, but it did have a new front wheel bearing/hub unit fitted last spring. After removing the shield it was of course totally quiet, which was a relief.  When putting the wheel back on I found myself wishing for a wheel locator pin like Alfa Romeo used to supply with the 164. Getting those lug nuts in is a complete PITA....

 

I've ordered a new one. its a common VW/Audi/SEAT/Skoda part.....so now I know what I'm doing with at least part of next weekend...

[silver1011]

A common complaint.

 

Whilst the rattling is very disconcerting it sounds worse than it is.

 

I too can sympathise with the frustration of how difficult it is to remove and install a replacement.

 

In my experience the most common cause for failure is when the wheels are removed. if they are allowed to drop off the hub without being supported they catch the shield which after a couple of times and several thousand miles of vibration elongates the holes eventually resulting in its demise.

 

 

 

 

 

 

 

 

[alfalincs]

Oh dear......so now I can expect the other disc guards to fall apart as well can I ?  As the same guard/part number is fitted across the entire VAG group range I expect  there is a regular little ongoing epidemic of disc guard failure..😒   Its not very good design is it, and they don't give them away.  I understand it is going to be the wrong kind of 'fun' getting the fixings out and fitting the new guard. Hey ho, what are saturday mornings for anyway....😐

[J.R.]

VAG might not give them away but there are loads of pattern part ones available, I have never paid more than €10 for one.

 

I dont think that dropping the wheel on them when removing causes the failure, its a combination of rust & metal fatigue at a stress raiser, when they are about to fail dropping the wheel on them will help them on their way.

 

It was quite obvious when all of mine were beginning to fail and needed replacement, one hole will break away before the others and the corrosion was very advanced and would warrant changing the shield on its own.

[KenONeill]

General hint - these items are not compulsory fitments, at least in the UK.

[seriesdriver]

Agree with the above I would be in no rush to replace it they just seem to be there for stones to wedge behind and make a screeching noise. 

[flybynite]

10 hours ago, KenONeill said:

General hint - these items are not compulsory fitments, at least in the UK.

 

58 minutes ago, seriesdriver said:

Agree with the above I would be in no rush to replace it

 

They stop road crap getting on the brakes and they stop brake dust getting on the suspension and brake lines. They direct air onto the brakes to help cooling and keep brake dust away from the braking surface.

 

Have you seen the state of the calipers/disks/pads on a modern car running without dust shields? They don't tend to be long for this world. Not something I would be keen to do.

 

Had the same dust shields on a VAG car for over 100K miles and they are still fine. Anything will fail if abused or neglected, however they are considered a service item and most good places replace them at the same time as the brakes.

 

They are easily replaced if you pull the hub, which is a simple matter if you have the correct hub puller. It is why you should not mess with your brakes unless you have the right knowledge and equipment.

[KenONeill]

@flybynite Nonsense, yes (and the shielded discs from the other axle on the same car), more nonsense which gives a good idea where you took your screen name from!  And irrelevant since I never mentioned removing them, just observed that they're not compulsory.

[flybynite]

14 minutes ago, KenONeill said:

@flybynite Nonsense, yes (and the shielded discs from the other axle on the same car), more nonsense which gives a good idea where you took your screen name from!  And irrelevant since I never mentioned removing them, just observed that they're not compulsory.

 

If you made sense yourself mate I would give you a proper answer. 

 

I am suggesting leaving the manufacturers kit on the car, as designed, for good reason. Then looking after it and replacing it using the proper tools and methods when they need it.

 

If you disagree with that and think it is nonsense then good luck to you 

 

Merry Xmas !

[Ootohere]

Strange thing about the protection the dust shields provide is when someone discovers the discs are losing the braking surface it is the side nearest the guard that is red with rust and was missed as the outer looked so so and as usual for a VW group component. Cosmetic to worse than that, but something that gets an Advisory at services as needing renewed.

More attention needed to the discs on both sides.

[Tilt]

How do you 'look after' a brake disc shield???

[seriesdriver]

3 hours ago, flybynite said:

 

 

 

 

 

 

  however they are considered a service item and most good places replace them at the same time as the brakes.

 

 

 

Really ? Do you have an evidence to back up this statement ? not something I have come across. there was one missing on my son polo when he got it 4 years ago, never mentioned on mots and my trusted garage replaced discs and pads this year no mention of shield at all. 

Edited 30 December, 2019 by seriesdriver
spelling

[KenONeill]

2 minutes ago, seriesdriver said:

not something I have come across.

Me neither, but don't expect a useful answer from flybynite since his answer to me was a mixture of irrelevant and insulting.

[flybynite]

2 hours ago, Tilt said:

How do you 'look after' a brake disc shield???

 

I clean and check them when I check and clean the brakes every time I change tyres from summers to winters and back again. Tin of brake cleaner does all 4.

 

When I take pads or disks (usually both) off to change or re-dress them I take the shields off, 5 mins with a wire brush, some jenolite and a rattle tin of satin black and back everything goes. Bit of copper grease on the studs that hold them on and they come off easy next time.

 

Not rocket science really

 

3 minutes ago, seriesdriver said:

trusted garage replaced discs and pads this year on mention of shield at all. 

 

Let me put it like this, If I take off brakes and the dust shields are less than perfect and I have any doubt they will make it to the next time, they get replaced. It is how I was taught and how the places that do work on my machines also work.

 

As far as the Octavia goes it forms part of the "Inspecting brake system for leaks and damage" check on the inspection services. If they do not inspect things like condition and security of shields on a brake inspection I would go elsewhere.

 

As any other item like disks or pads it is checked and replaced if necessary. they are to all intents and purposes a consumable item, but with a bit of looking after they can last.

 

If manufacturers could get away without them they would, they can't

 

22 minutes ago, KenONeill said:

Me neither, but don't expect a useful answer from flybynite since his answer to me was a mixture of irrelevant and insulting.

 

Just glad I would not be buying a car owned by you if you think driving around with no shields is a good thing.

 

But if you are happy that is all that counts 

[J.R.]

If most good places did replace them at the same time as discs/pads the pages of the forum would be awash with complaints of unnecessary work.

 

Its not something that I ever used to purposely check but like flybynite I would visually inspect everything, my MK1 did 500000 kms and they were as good as new. When I bought my MK2 which had spent a couple of years in a seaside town I could see that they were all severely corroded and decided to change them with the discs, on dismantling I found many of the bosses had fractured and they were hanging on with a wing and a prayer so now I give them a visual inspection and a good old push & pull.

 

Cant recall if it was the front or rear that needed the hubs removed to remove them, but they were so flimsy I just folded them till they snapped I cut a slot to the centre hole on the new ones to aid fitting and subsequent removal if ever needed.

 

They are so cheap I doubt that I would remove them to derust and paint but could do so now if needed, however that wont be the case for a standard fitment.

Edited 30 December, 2019 by J.R.

[fabdavrav]

Those shields also stop the rubber boots on the ball joins & the ABS wires from melting...

 

Several people in the USA (I'm on a USA Golf forum) who track their MK7 Golfs..(say a 2hr drive on the back country roads here)...have got the brakes quite hot & found out to their surprise that removing those shields is NOT a good idea!!

[J.R.]

"They direct air onto the brakes to help cooling"

 

I forgot to debunk that claim.

 

Removing them improves brake cooling and delays brake fade significantly but the heat liberated can have secondary consequences, I have shrunk & distorted track rod end gaiters on a Caterham.

 

I have never had brake disc corrosion on any car where I have removed the backplates (and there have been many) and I have pretty much always suffered corrosion both inside and out when they have been retained, hard to understand why it should affect both sides unless its heat related.

 

As an aside, I am running winter wheels for the first time ever, steel rims and plastic hubcaps, the car (my Octavia)  has done maybe 1500 miles on them and they are 10 times cleaner than the alloys on the Yeti the wheels were intended for, that has done maybe 20 miles since being valeted & jetwashed.

 

I dont mind the look of the wheeltrims, they are proper Skoda ones and another benefit is that you cannot see the rusty brakes discs and calipers.

Edited 30 December, 2019 by J.R.

[*JP*]

I was under the impression that one of the functions of these shields was to reduce water build up on the discs,especially at speed on a very wet road,so that on sudden hard braking the response was a fraction sooner (which could make a significant difference!)

 

No one has mentioned this,but if I am wrong,I will be happy not to take offence !

[J.R.]

All disc calpers have a certain amount of drag on the pads to keep the braking surface dry, when I have removed backplates I have not noticed any deterioration in brake response in wet weather.

 

That said I recently had to drive through several floods in my Octy 2 (with backplates) and "dried" the brakes immediately afterwards as soon as safe to do so, I was surprised that 100m or so after the immersion there was very little initial bite.

 

Not the same thing I realise and the presence or absence of backplates would have made no difference.

[silver1011]

6 hours ago, Tilt said:

How do you 'look after' a brake disc shield???

 

Don't catch them when removing the wheels. The sound they make when the alloy catches them is very familiar to anyone who has spent time in a garage or main dealers.

 

Corrosion plays it's part but it is the weight of the wheel temporarily pushing on the guard that starts the elongation of the thin metal.

[ScoutCJB]

8 hours ago, flybynite said:

 

 

They stop road crap getting on the brakes and they stop brake dust getting on the suspension and brake lines. They direct air onto the brakes to help cooling and keep brake dust away from the braking surface.

 

Have you seen the state of the calipers/disks/pads on a modern car running without dust shields? They don't tend to be long for this world. Not something I would be keen to do.

 

Had the same dust shields on a VAG car for over 100K miles and they are still fine. Anything will fail if abused or neglected, however they are considered a service item and most good places replace them at the same time as the brakes.

 

They are easily replaced if you pull the hub, which is a simple matter if you have the correct hub puller. It is why you should not mess with your brakes unless you have the right knowledge and equipment.

 

+1

 

mine failed and dislodged as yours did so I replaced both sides on the front of my Oct 3.

 

The Wife's Cooper S doesn't have rear shields on and the brakes are always clogging up.

[alfalincs]

Well I'm flabbergasted at the acceptance of what is essentially a crap quality component ! I've never had to replace disc guards on ANY other car I've had in 49 years, and in the early days my cars were pretty elderly when I got them. I'm pretty fed up with the things that have gone wrong on this 4x4 estate that shouldn't at such low  miles (leaking slave cylinder so new clutch....front wheel bearing failure, new water pump, now this)  and I give a hollow laugh when people cast aspersions on Alfas as more has gone wrong in 40.000 miles on the Octavia than went wrong in 140,000 miles on my previous Alfa 156 Sportwagon. Catching the wheels on the discguards when removing the wheels ?  Who does that anyway, and even if you did it should only damage them if they are made of foil. Do you seriously have to take a front hub out to replace them ? I flippin hope not. It seems like there are three torx headed screws...and as long as you can get at them.

 

I think I know where this all started..the mission for VAG was lightness to help with emissions, and boy are these lightweight at 140 grammes. The replacement came today and is made in Spain as opposed to Germany on the original. It might even be a pattern part as there is less coding on it, but they both weigh the same. This is our eighth Skoda since 1990 and whilst in many ways it is impressive, in other ways it is proving to be the least robust Skoda of the lot, and it doesn't get hard use at all. 

[alfalincs]

On 30/12/2019 at 18:26, *JP* said:

I was under the impression that one of the functions of these shields was to reduce water build up on the discs,especially at speed on a very wet road,so that on sudden hard braking the response was a fraction sooner (which could make a significant difference!)

 

No one has mentioned this,but if I am wrong,I will be happy not to take offence !

 

They are certainly there to deflect water away from the disc in very wet weather, and the wheel performs the same function on the other side. Anybody who rode motorbikes when they first went from drum brakes to discs soon found out that you could end up with no brakes at all until the pads had cleared the water. This was worse by far on some of the Japanese bikes (like my Suzukis) that came with stainless discs for largely cosmetic reasons. The rusty looking cast irons discs were far better as brakes in both the wet and the dry....no guards of course..

[Ju1ian1001]

On 30/12/2019 at 16:41, flybynite said:

 

I clean and check them when I check and clean the brakes every time I change tyres from summers to winters and back again. Tin of brake cleaner does all 4.

 

When I take pads or disks (usually both) off to change or re-dress them I take the shields off, 5 mins with a wire brush, some jenolite and a rattle tin of satin black and back everything goes. Bit of copper grease on the studs that hold them on and they come off easy next time.

 

Not rocket science really

 

 

Let me put it like this, If I take off brakes and the dust shields are less than perfect and I have any doubt they will make it to the next time, they get replaced. It is how I was taught and how the places that do work on my machines also work.

 

As far as the Octavia goes it forms part of the "Inspecting brake system for leaks and damage" check on the inspection services. If they do not inspect things like condition and security of shields on a brake inspection I would go elsewhere.

 

As any other item like disks or pads it is checked and replaced if necessary. they are to all intents and purposes a consumable item, but with a bit of looking after they can last.

 

If manufacturers could get away without them they would, they can't

 

 

Just glad I would not be buying a car owned by you if you think driving around with no shields is a good thing.

 

But if you are happy that is all that counts 

No wonder you replace the disc back plates fairly often, you know that BRAKE CLEANER actually desolves paint as it's a solvent  ( before you say anything i have been a car mechanic/mot tester for 24 years) brake cleaner should only be used on NON PAINTED parts, if i'm not mistaken disc back plate's are painted black on almost every car on the road. The back plates don't influence any air to cool brakes on normal every day cars, thats why almost all now have vented discs, the sole purpose is to protect dust covers and brake lines from being damaged by heat radiating from the discs, a side effect being the inner face of the discs corrode and pitt before the outer face. And in my entire time in the motor trade checking the condition of back plates has never been on any service check sheet or list, just discs, calipers, pads,shoes and drums, metal brake pipes and flexible brake hoses. this includes VAG products

Edited 2 January, 2020 by Ju1ian1001

[flybynite]

27 minutes ago, Ju1ian1001 said:

you know that BRAKE CLEANER actually desolves paint as it's a solvent 

 

I think you are confusing brake cleaner with carb cleaner. The solvents in brake cleaner won't remove cured paint especially the 2-pack paint the shields are painted with. It will soften powder coating but I don't powder-coat my brakes

 

26 minutes ago, Ju1ian1001 said:

condition of back plates has never been on any service check sheet or list

 

Is there any better time to replace dust shields than when the disk is off for replacement? Or do you just charge for all that work again when they need replacing?

 

30 minutes ago, Ju1ian1001 said:

The back plates don't influence any air to cool brakes

 

The car these come off has vented disk brakes, look like they direct flow to me

But they also protect ABS sensors and wiring from brake heat

 

25 minutes ago, Ju1ian1001 said:

No wonder you replace the disc back plates fairly often

 

I don't, mine are still going well some at well over 100K cleaned as above