Mk7 Golf GTI - severe scoring of rear discs
Discussion
Anyone come across this before? I've searched PH and drawn a blank but there's a thread on the Golf R forum and another Golf one.
One of the rear discs (other side's the same):
Here's one of the fronts by comparison:
The wheels and calipers aren't always that dirty, honest... Car last used three days before pics taken.
Total mileage currently 22K done in about 26 months. However, scoring had begun long ago - maybe a year/12K miles.
In 40-odd years of motoring and generally having new cars at each change, and putting 40K to 80K miles on them I've never had an issue with brakes or even needed new pads. I don't hang around either. I wouldn't say I'm a heavy braker but stopping 1.5 tonnes of car from 70 mph or so puts the discs and calipers to work and ought to keep the discs clean. And I haven't been off road or driven in 'abrasive' conditions.
My local dealer says I need new discs and pads. What, at 20K miles? Any ideas as to cause or how to address? Worth getting them skimmed?
One of the rear discs (other side's the same):
Here's one of the fronts by comparison:
The wheels and calipers aren't always that dirty, honest... Car last used three days before pics taken.
Total mileage currently 22K done in about 26 months. However, scoring had begun long ago - maybe a year/12K miles.
In 40-odd years of motoring and generally having new cars at each change, and putting 40K to 80K miles on them I've never had an issue with brakes or even needed new pads. I don't hang around either. I wouldn't say I'm a heavy braker but stopping 1.5 tonnes of car from 70 mph or so puts the discs and calipers to work and ought to keep the discs clean. And I haven't been off road or driven in 'abrasive' conditions.
My local dealer says I need new discs and pads. What, at 20K miles? Any ideas as to cause or how to address? Worth getting them skimmed?
The Wookie said:
Is it actual scoring or is it just that some areas have been unevenly cleared of corrosion/salt?
As said, the rears to very little on car like this, particularly a hot model which will have bigger brakes on the front. If you're a light braker and/or do a lot of motorway miles then it could easily happen, either through deterioration of the disc itself or through deterioration of the pad and then the disc as a consequence.
Worth giving it a good bedding cycle (I.e. a controlled pasting) to see if it clears up, if you still struggle you could even try loading the car up with some weight in the back and braking really hard to get the EBD going in shifting some pressure to the rear.
Personally if it's not creating any noise issues, judder or noticeable drop in brake performance I'd be inclined to ignore it. The first two will more than likely appear before the last.
It is actual scoring. I accept that my car usage and driving style combine to minimise brake wear but I've been doing this for years and it's never happened before.As said, the rears to very little on car like this, particularly a hot model which will have bigger brakes on the front. If you're a light braker and/or do a lot of motorway miles then it could easily happen, either through deterioration of the disc itself or through deterioration of the pad and then the disc as a consequence.
Worth giving it a good bedding cycle (I.e. a controlled pasting) to see if it clears up, if you still struggle you could even try loading the car up with some weight in the back and braking really hard to get the EBD going in shifting some pressure to the rear.
Personally if it's not creating any noise issues, judder or noticeable drop in brake performance I'd be inclined to ignore it. The first two will more than likely appear before the last.
I'm in two minds about what to do: get it sorted (at some considerable cost) or leave it (on the basis that the brakes still make a fine job of stopping the car). A mate who does a fair bit of amateur spannering reckons the rear pads are a bit thin.
ETA: I think the discs are too far gone to respond to some stand-on-pedal braking.
Edited by Maxym on Wednesday 1st March 19:34
nickfrog said:
Sorry but that looks like deposit to me - which may feels to the touch exactly like scoring. I would go on a late night repeated intense braking session on the very edge of ABS triggering (x10 60 to 20) and see what happens. If it is scoring then no big loss but it is uneven glazing it should show signs of cutting through it.
I'm probably wrong but worth a check.
If it were a deposit of some sort it would scrape off, wouldn't it? I mean, I could see if I could remove what looks like scoring with a scraper of some kind...?I'm probably wrong but worth a check.
Thanks for all the comments, suggestions, etc. Much appreciated.
CrutyRammers said:
If you really think that, then you shouldn't be driving on them.
But they're not. The discs look virtually untouched, wear-wise, and that scoring is a fraction of a mm deep. The brakes won't even notice. I'd do some hard stops and if it's fine, not worry about it, personally.
I meant, to polish them up. Braking performance is just great.But they're not. The discs look virtually untouched, wear-wise, and that scoring is a fraction of a mm deep. The brakes won't even notice. I'd do some hard stops and if it's fine, not worry about it, personally.
Update... Spoke to VW dealer today, who say that their observations on the rear discs were just a 'heads up' for my info. Well they did suggest they change the discs and pads and reminded me about it a couple of months ago. Money-grabbers. 
Turns out the situation isn't even half-way dire or even that abnormal. Pah! As I thought...
Interestingly the rear pads are 30% worn and the fronts only 20%. I suspect that could be down to the car having the Performance Pack with bigger front discs.
Over the weekend I cleaned up the discs with emory (made them a smoother though they didn't look that different) and drove 200 miles doing pretty heavy stops when I could. Made no difference to the appearance of the discs.
So everything's staying as it is. In future I will carry on braking in the intelligent fashion that has served me well for decades but do a short drive after washing the car so as to dry the brakes off (I do this with my Porsche anyway).
Thanks for your input, folks. Case closed.
Turns out the situation isn't even half-way dire or even that abnormal. Pah! As I thought...Interestingly the rear pads are 30% worn and the fronts only 20%. I suspect that could be down to the car having the Performance Pack with bigger front discs.
Over the weekend I cleaned up the discs with emory (made them a smoother though they didn't look that different) and drove 200 miles doing pretty heavy stops when I could. Made no difference to the appearance of the discs.
So everything's staying as it is. In future I will carry on braking in the intelligent fashion that has served me well for decades but do a short drive after washing the car so as to dry the brakes off (I do this with my Porsche anyway).
Thanks for your input, folks. Case closed.
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