Rear Brake Discs - New kind of problem!

[Jason88]

So I've never seen this one before. Looking for opinions! Greenline II, 2012, 65K miles and full service history. No discs replaced to date.

 

Rear brake discs (both sides) are corroded. MOT three weeks ago specified "rear brakes badly corroded".

 

When putting air in the tyres, I noticed the face of the discs has started to shear off!

 

I don't think it was this bad when I took it for the MOT, but heavy breaking and extreme weather over the last couple of weeks may have impacted.

 

Has anyone seen this before? I always assumed discs were one piece of iron, without a "face" per se.

 

The corroded areas are definitely ~1mm lower than the clear areas.

 

This may be why facelift/newer models switched to rear drum brakes?

 

Safe to drive the 500 miles home (+2500 more to next service?), then have the rear discs and pads replaced, or get it fixed here and now? Front brakes are perfect.

[Rooted]

So off the road until replaced.   Not safe, you risk your and others lives.  & a crash / police / examiner will be a bit displeased.

That is as bad as it gets, not uncommon if you look at the many similar threads in BRISKODA.

 

When was this last service done that gives it a Full Service History.

Not like Skoda Main Dealers not to advice discs worn / scored / corroded, in need of replacement.

 

Just shows how UK MOT's are Minimum requirement on the day.   Very risky.

Edited 13 March, 2018 by AwaoffSki

[AGFalco]

29 minutes ago, Jason88 said:

but heavy breaking and extreme weather over the last couple of weeks may have impacted.

 

Bad weather/wet weather yes. Heavy braking no.

 

I take the brakes apart every autumn and clean off any rust and re-grease the pads.

This helps to stop it happening.

The rust creeps up/down the face from the edge.

 

Thanks Ag Falco

 

 

[Breezy_Pete]

29 minutes ago, Jason88 said:

Safe to drive the 500 miles home?...

 

Sub-optimal. Especially now you've put it on record that you were aware they were like this.

 

I think they are a solid piece of cast iron, but I guess there'll be a surface treatment, and/or possibly just an 'in use' thermal thing going on?

 

Will be carving the pads to bits whenever used!

[2ndskoda]

Not trying to be a smartass -  BUT  - a note of caution to anyone who may have misread AG Falco's earlier  comments.

 

REGREASING THE PADS refers to the backing NOT the pad surface!

I am not nitpicking here, but some years ago we had 2 customers who (to stop brake squeal) put a smear of grease on the pad material itself.

Hope this clarifies the matter -  comments made with no intended offence to AGFALCO

[KenONeill]

@Jason88 - The "face" of a brake disc is the area that the pad rubs against.

 

@Wino - Correct; it's quite common for brake discs to be case hardened (as the name implies it's a surface treatment).

[mrgf]

I believe discs can be ground/resurfaced to some degree but the wear limit must not be reached. Having said that, they are not that pricey from many outlets and as they are such a safety issue, why risk it? Unless you have the correct equipment and know-how, it will probably cost more to get this done anyway!

 

I always expect to see slight corrosion on discs of vehicles that have been driven in poor weather, then parked a few days. Even surface spots after just a day. 

 

If you can scrape it off with a plastic or wooden tool, NOT metal, I'd risk the drive but otherwise, change them first! If it comes off that easily, fair enough but if it comes off here and there, the brakes may not work effectively and could potentially be dangerous. This will allow you the option of dealing with the situation more leisurely but I would almost certainly change them very soon!

 

If the MOT station were on the ball, they should know the discs are thick enough and at least at minimum safety levels, otherwise they would have failed you. 

 

Really, this will come down to how safe YOU feel, driving the vehicle. Some people assume an MOT means the car is safe till next year but it only means you passed the minimal standards there and then. I have known people to "Borrow" wheels and tyres from a mate, to pass, then swap back again. Stupid is as stupid does!

[Breezy_Pete]

@mrgf pop your glasses on and then have another look at the photos. That's not surface rust that could be scraped off, it's effing great slabs of disc surface dropped off!

[mrgf]

I can see that, thank you!  Your remark doesn't take account of my comment of having the discs re-ground, which will remove this sh-stuff but will only delay the inevitable and most likely cost as much if you can't do it yourself. Additionally, others may look at threads that attract them due to similar issues. If this issue was spotted earlier, action could have been taken. My comment on surface rust was a follow on, hence the change of paragraph, offering insight to less drastic situations. You would not bung a set of discs just due to surface corrosion, which can be cleaned effectively. The idea of cleaning them off with a scraper will be too late in this instance but someone else may be luckier and have light corrosion so the comment stands!

 

 

I think you kind of mis-understood what I meant. Perhaps fairly or perhaps to make a sarky comment and I do like a joke as much as the next man.

[Rooted]

The discs are shagged.   I have been having discs skimmed for £10 a disc for years now,  mates rates where dealerships have discs skimmed.  But not when discs are about £30 a pair. 

[Warrior193]

9 hours ago, 2ndskoda said:

Not trying to be a smartass -  BUT  - a note of caution to anyone who may have misread AG Falco's earlier  comments.

 

REGREASING THE PADS refers to the backing NOT the pad surface!

I am not nitpicking here, but some years ago we had 2 customers who (to stop brake squeal) put a smear of grease on the pad material itself.

Hope this clarifies the matter -  comments made with no intended offence to AGFALCO

Many moons ago, around when Noah was thinking about getting into boat-building, I was serving my electrical apprenticeship. One of the office staff members brought their car battery to the workshop for charging. Hydrometer test showed very strange looking electrolyte (dark / oily) in all cells - it turned out that owners father had put engine oil in the battery to stop the generator (many moons ago, remember) from making a "squeaking" noise!      

[Warrior193]

22 hours ago, Jason88 said:

So I've never seen this one before. Looking for opinions! Greenline II, 2012, 65K miles and full service history. No discs replaced to date.

 

Rear brake discs (both sides) are corroded. MOT three weeks ago specified "rear brakes badly corroded".

 

When putting air in the tyres, I noticed the face of the discs has started to shear off!

 

I don't think it was this bad when I took it for the MOT, but heavy breaking and extreme weather over the last couple of weeks may have impacted.

 

Has anyone seen this before? I always assumed discs were one piece of iron, without a "face" per se.

 

The corroded areas are definitely ~1mm lower than the clear areas.

 

This may be why facelift/newer models switched to rear drum brakes?

 

Safe to drive the 500 miles home (+2500 more to next service?), then have the rear discs and pads replaced, or get it fixed here and now? Front brakes are perfect.

That's one of the strangest things I've ever seen on discs - that looks for all the world that these have some sort of laminated surface, which is de-laminating.

[rum4mo]

These pictures are very impressive, I could spend an hour or so knocking all that rust off, it looks like it has been wearing nicely over the complete swept area, then at some point, probably after sitting in a used car area, it has grown that rust that is now not getting grabbed by the pads!

 

I'll guess the pads are not as free as they should be to move in the calliper carriers either, old bits old followed by a good clean up and then new discs and new pads needed.

 

Edit:- to the OP these discs are not shearing, you would know very quickly if they were, I returned from a holiday abroad to find that my wife's Fiesta had suddenly acquired serious vibration in the front brakes, when I went to replace them the one that was starting to shear off broke off completely leaving only the "top hat" section on the hub, I did not see that situation coming!

Edited 14 March, 2018 by rum4mo

[Breezy_Pete]

18 minutes ago, rum4mo said:

I could spend an hour or so knocking all that rust off

There wouldn't be any point. As the OP says the top millimetre of the disc surface has fallen off, exposing those rusty areas beneath.

 

@mrgf, I genuinely thought - from what you wrote - that you thought the rust was on the surface, and so could be removed relatively easily. No offence intended.

[rum4mo]

1 minute ago, Wino said:

There wouldn't be any point. As the OP says the top millimetre of the disc surface has fallen off, exposing those rusty areas beneath.

 

@mrgf, I genuinely thought - from what you wrote - that you thought the rust was on the surface, and so could be removed relatively easily. No offence intended.

 

I still can't see that it is the rusty stuff under the silver steel, I've never ever seen that and I've seen discs that have been used down to their limit and below, even when "blown up" in magnification, that rust still, to me looks like it is above the silver intact but worn down swept outer areas - either way, that is very unusual for a disc to end up looking like that - heavily corroded yes, but showing sliver steel sections in amongst the heavily rusted area, no, not seen that before.

 

I'd be very suspicious about discs having surface treatment, these discs normally get their "qualities" from the steel used, and as the wear limits are way deeper than any surface hardening would exist that is the way I've always understood things to be.

[Jason88]

On 13/03/2018 at 19:39, AwaoffSki said:

When was this last service done that gives it a Full Service History.

Not like Skoda Main Dealers not to advice discs worn / scored / corroded, in need of replacement.

 

Just shows how UK MOT's are Minimum requirement on the day.   Very risky.

 

I don't have docs with me, but less than 8 months and 5k miles ago. They did recommend we replaced the discs next time the brake pads were done, but even that wasn't implied it was at the next service (pads had 4-6mm on last service I think?)

 

Agreed!

 

On 14/03/2018 at 16:46, Wino said:

@mrgf That's not surface rust that could be scraped off, it's effing great slabs of disc surface dropped off!

 

∆∆This.

 

One of the garages I went to between OP and now - the mechanic was pulling/chipping off the silver surface with his fingernail to reveal the rust beneath like a scratch card! He also called it a "cheesegrater" for my brake pads.

 

22 hours ago, Warrior193 said:

That's one of the strangest things I've ever seen on discs - that looks for all the world that these have some sort of laminated surface, which is de-laminating.

 

∆∆Exactly this.

 

22 hours ago, Wino said:

There wouldn't be any point. As the OP says the top millimetre of the disc surface has fallen off, exposing those rusty areas beneath.

 

∆∆Again, this.

 

22 hours ago, rum4mo said:

I still can't see that it is the rusty stuff under the silver steel, I've never ever seen that and I've seen discs that have been used down to their limit and below, even when "blown up" in magnification, that rust still, to me looks like it is above the silver intact but worn down swept outer areas - either way, that is very unusual for a disc to end up looking like that - heavily corroded yes, but showing sliver steel sections in amongst the heavily rusted area, no, not seen that before.

 

I promise you, it was rust under the silver steel. As I say, like a scratch card where you win rust!

 

The good news is I did the sensible thing, and this is how they look now. Phew! Expensive but worth it.

 

Thanks for all the input!

[Rustynuts]

Best, most sensible solution. Anything else would've been both dangerous and irresponsible.

[rum4mo]

That is just crazy, but as you have said it has happened like that then so be it, I would not expect to see one like that again for a long time - if ever!  It might have been interesting to know which supplier made that disc as they should not be able to "go" that way.

 

If you knew nothing about how these discs were made/used/refurbished, you might think that it was just a badly "re-built/re-faced" disc - but hopefully that is not possible.

[Jason88]

13 minutes ago, rum4mo said:

If you knew nothing about how these discs were made/used/refurbished, you might think that it was just a badly "re-built/re-faced" disc - but hopefully that is not possible.

 

I bought the car brand new with 24 miles on the clock when I picked her up. I'm the only owner.

 

Picked up from my local Skoda dealer. The discs were never replaced (until now), and never refaced.

 

I really, really trust these were Skoda's own. Eek!

Edited 15 March, 2018 by Jason88

[rum4mo]

That is not good, it would have been easier to simply think/hope that some back street operation was sourcing some special "funky" cheap discs.

 

Worst I ever had with brake discs was my older daughter bought a used SEAT Ibiza from Arnold Clark in Edinburgh, that car, as we discovered later, had been a leased car supplied by Arnold Clark Edinburgh to someone in Liverpool, it had some work done on the front brakes by the SEAT main dealer in Liverpool while still under warranty, the first time I checked the front brakes out I discovered that one side had the correct disc, the other side had the previous version of that disc, nearly same diameter but thinner disc and slightly different "top hat" section, so when I went to replace the pads, the new pads would not fit the "wrong" side. I was not impressed by that as I'd expect the previous models had slightly different callipers!  At least it got its discs changed by me at that point!

[Breezy_Pete]

Email a link to this thread to Skoda UK? That would be met by a deafening silence, I suspect.

[Ju1ian1001]

I have seen many a brake discs like that, the discs are case hardened (heat treatment, so they can with stand the wear and heat cycles they go through.)

 

They start to pit first then they rust and corrode, it's this that breaks up the surface and cause rapid corrosion to the disc, once this happens the only option is to replace them (skimming won't work) The op did the best and safest thing.

 

[Rooted]

Jason88,

How expensive were they?

I pay £114 including VAT for 4 Ferodo Discs and pads.

[Jason88]

2 hours ago, Wino said:

Email a link to this thread to Skoda UK? That would be met by a deafening silence, I suspect.

 

Probably, but it's no drama, so I'm not going to waste their time.

 

2 hours ago, Ju1ian1001 said:

I have seen many a brake discs like that, the discs are case hardened (heat treatment, so they can with stand the wear and heat cycles they go through.)

 

They start to pit first then they rust and corrode, it's this that breaks up the surface and cause rapid corrosion to the disc, once this happens the only option is to replace them (skimming won't work) The op did the best and safest thing.

 

This is great to know! Glad I'm not the only one. Interesting they're case hardened. The things you learn...

 

2 minutes ago, AwaoffSki said:

Jason88,

How expensive were they?

I pay £114 including VAT for 4 Ferodo Discs and pads.

 

£189 - but I went to a local garage I trust/know from years ago (first time I haven't used a Skoda dealer on this car).

 

Skoda's quote was £235 - but I was more worried that they didn't know if they could fit me in before the weekend when I have a long drive to do.

[Rooted]

Was that all 4 for £189 or a pair / rears.

 

Skoda have a National Pricing price, Participating Dealers.

£235 a pair.

http://skoda.co.uk/finance-and-offers/service-and-maintenance/simply-fixed 

Edited 15 March, 2018 by AwaoffSki