Brake Disc Corrosion - The Extreme Edition...

GSB · June 6, 2006, 17:50

Look what my dealer just found:

Both my front discs look like this despite only being 18 months and 20,000 miles old... The odd thing is, that the corrosion is on the inside of the discs only, the outside are perfect, with not even a hint of rust...

The car is hardly ever driven in bad weather, and is garaged every night.

aaronjb · June 6, 2006, 18:26

Looks more like a record than a brake disc..

Replaced under warranty, I hope?

kanujunkie · June 6, 2006, 18:30

strange how it wore that pattern, looks almost like half a tonne of stones got stuck up in there s:? :? s:?

GSB · June 6, 2006, 19:46

Quote from: "kanujunkie"strange how it wore that pattern, looks almost like half a tonne of stones got stuck up in there s:? :? s:?

Yes, except both discs were exactly the same, and the grooves you can see arent scored, like when you run out of pad material for instance, but rotted. Its like the metal has been etched away rather than scraped... Wierd.

Oh, and yes, they did it under warranty. In fact I had no idea there was any problem prior to taking it in for a service. They found it, they fixed it, I had no input whatsoever to the process.

Anonymous · June 6, 2006, 19:49

Looks the same as mine did last year, a mechanic friend of mine suggested that it was problem with the metal. They didn't replace them under warranty till I took them into the showroom and started complaining

Beowulf · June 6, 2006, 19:56

I have the same problem,but mine are both sides and they are just over a year old.I replaced them with genuine Toyota parts as I was advised to.This time I will be using aftermarket ones!! s:x :x s:x bleedin Toyota,lol

Anonymous · June 6, 2006, 20:11

Mine were skimmed under warranty on the 30k service needless to say they are just about shigged (sp) now, recon I'll be going down the "get & fit myself road s:wink: :wink: s:wink:

Anonymous · June 6, 2006, 21:04

mine were reoplaced this time last year, again the corriosion was on the inside face only.

Personally i blame single piston sliding calipers (like ours) of they were twin piston opposed calipers this would probably not happen

But then im an idiot and dont know much so i could be wrong s:oops: :oops: s:oops:

Anonymous · June 7, 2006, 17:58

I thought i'd read somewhere that they were two piston ones, so I guess you can't be that much of an idiot!!!! s:wink: :wink: s:wink: s:lol: :lol: s:lol:

kanujunkie · June 7, 2006, 18:07

Quote from: "jamesr1"I thought i'd read somewhere that they were two piston ones, so I guess you can't be that much of an idiot!!!! s:wink: :wink: s:wink: s:lol: :lol: s:lol:

nope definatley single piston

Anonymous · July 24, 2006, 12:45

Greetings all,

Seems I am another victim of the MR2 front disc inside face corrosion problem. I am on my second set of discs now and am looking at replacing them again after they were flagged on my most recent service.

The first time this happened I had only had the car a short time (bought from a rather unhelpful dealer in Manchester) and I did eventually get them replaced under warranty. As was posted by Bowman, this was only after kicking up a stink.

The discs that were taken off looked just like those in the picture. However, I kept these discs as I figured I could get them skimmed and have taken them out of storage after a year to do so. What is interesting is that all that horrible ringed/scored material has now flaked off to reveal a very even (yet mildly rusty) surface underneath. I am now curious as to whether that scored material was actually the brake discs itself, or just baked on debris from the pads? (Sorry, I'm a bit of a nerd s:idea: :idea: s:idea: ).

I've shown the old discs to a mechanic buddy of mine (he supports a local rally team up here) and he is certain this is a result of callipers not working effectively on the back face. This means the surfce oxidation (rust) does not get cleaned off by the pads during normal use, hence the tendancy to rust severly.

I am going to strip down the brakes myself to see what's going on, but it sounds like the sliding mechanism may be obstructed.

Having said all this, I would be interested to hear if this problem is limited to Toyota discs. i.e. do 3rd part discs suffer the same fate. This would help isolate calliper problems from materials issues.

Thanks for listening.

Tobes.

Anonymous · July 24, 2006, 19:34

Tobes, keep us updated with your findings

BenF · July 26, 2006, 13:39

Hmm, not sure if anyone has identified the problem with the roadster, but certainly on the Mk2 the sliding pins the front calipers moved on had a tendency to seize up. Cleaning them up, and re-greasing them with sliding pin specific grease (NOT Copperslip - it dries and hardens!) the problem was cured.

ChrisGB · July 31, 2006, 11:27

Hi

Having had the discs flagged up on service for scoring, I was planning to replace as wear and tear. Lookig at this, I went out and had a look for myself and my discs look pretty much identical to that.

How can they have got it so wrong design wise? Been on to the local Toyota dealer who is going to ask Toyota to cover it under warranty.

Chris

Tem · July 31, 2006, 12:04

Quote from: "ChrisGB"I went out and had a look for myself and my discs look pretty much identical to that.

How can they have got it so wrong design wise?

I bet you've driven on salted roads?

It just does that. To most cars, not just MR2's, nor even just Toyota. s:oops: :oops: s:oops:

Wabbitkilla · July 31, 2006, 13:12

My Yaris did the same is the picture.
Interesting reading leaving them for a bit of corrosion to get in there and remove this contamination. I wonder if it's the brake pads?

Anonymous · July 31, 2006, 13:14

I had brand new front discs put on my '2 when I bought it. Then two months later at the service Mr T said I needed new front discs because they were so badly corroded..... What? 2 months old!!!

Anonymous · July 31, 2006, 18:34

I replaced my 2001 discs yesterday at 36,000 mls. Front face fine, rear face severly corroded. A word of warning, my MR2 ended up on a car transporter last week in France because the friction material broke away from the backing steel plate on one of the inside pads. Still 5mm of material on the pad that broke way !! - caused by corosion ?
I used after marked discs so it will be interesting to see how they compare

ChrisGB · July 31, 2006, 22:24

Quote from: "Tem"
Quote from: "ChrisGB"I went out and had a look for myself and my discs look pretty much identical to that.

How can they have got it so wrong design wise?

I bet you've driven on salted roads?

It just does that. To most cars, not just MR2's, nor even just Toyota. s:oops: :oops: s:oops:

Hi Tem

I have only had the car a few weeks, so have never driven it on salted roads, however, I have had a few cars over the years and driven around 1.1 million miles, do much of my own servicing / repair and this is the first time I have seen anything like it. Disc wear, scoring and even heat fracture, yes, but this is something else.

The service guy at Mr T reckoned they corrode due to a comination of lack of use and poor airflow holding moisture round the back of the disc. Having never had this problem before, I reckon it is a design fault. Toyota would not be the first to get brake discs wrong. Ford had problems in the late 1990s when they changed alloy composition and had discs warping all the time. I bought a new car that had warped discs when I collected it and quite a few (5 if I remember correctl) others that developed warped discs in under 5000 miles.

I am looking forward to serious improvement in braking capability when it is fixed. Just a bit worried that at the moment the rear discs will be taking most of the load.

Chris

Keith J Singleton · July 31, 2006, 23:07

I had a MK1 MR2 for eleven years, 35,000 miles when I got it on original discs, full service history. It went on to do 162,000 miles until I sold it for the Roadster this last February. I replaced the front and rear discs after 127,000 miles because they were wearing thin, single piston, no problems.

How could they cock up the Mk3s brakes? s:? :? s:?

Keith

Tem · August 1, 2006, 05:22

Quote from: "ChrisGB"lack of use and poor airflow holding moisture round the back of the disc

If that's the problem, just take the shield off from the back, it also helps to keep the brakes a bit cooler when you're pushing it.

Might wanna check your local laws first though, over here they are a must, not that anyone ever checks them.

Anonymous · August 1, 2006, 08:48

Quote from: "ChrisGB"I am looking forward to serious improvement in braking capability when it is fixed. Just a bit worried that at the moment the rear discs will be taking most of the load.

Chris

The rears will never take most of the load as brakes are always bias to the fronts otherwise we would be leaving a pair of black lines on every brake application s:wink: :wink: s:wink:

ChrisGB · August 1, 2006, 21:05

Quote from: "Les"
Quote from: "ChrisGB"I am looking forward to serious improvement in braking capability when it is fixed. Just a bit worried that at the moment the rear discs will be taking most of the load.

Chris

The rears will never take most of the load as brakes are always bias to the fronts otherwise we would be leaving a pair of black lines on every brake application s:wink: :wink: s:wink:

Well more of the load than they would normally, so if braking at 50%, the rears would be doing a lot more of the work than they normally would. The car does feel a bit rear biased under braking and this would account for it.

Chris

ChrisGB · August 1, 2006, 21:07

Quote from: "Tem"
Quote from: "ChrisGB"lack of use and poor airflow holding moisture round the back of the disc

If that's the problem, just take the shield off from the back, it also helps to keep the brakes a bit cooler when you're pushing it.

Might wanna check your local laws first though, over here they are a must, not that anyone ever checks them.

First thing I thought of. I will have a look at the pipework routing and see if it is possible.

Chris

mg · August 17, 2006, 22:07

I noticed the inner fronts were scored as well (1 year, 6k miles!) told MrT during the first service and they replaced them under warranty today (had to buy the pads though, wear and tear item not covered).

What is the deal with these disks?