Is there a fix to the corroded inner disc face? As I was under a friends octy yesterday doing his service and giving it a once over and noticed both fronts had a band of thick rust around the outer edge on the inner face.

Today I am changing the discs and pads for him, but would like to know what the cause is so I can stop it happening again,

Cheers

Karl

I had mine nearly 7 years and not a problem . The inner piston seized?

Not using the brakes enough is normally the cause.

I dont think so, the pads and discs were new not long before he got the car back at the start of April (7k miles ago) so prob done 10k ish, the middle part if the inner face is worn, and quite a bit! It's like the outter part of the pad is missing! If the inner pad is making contact then in theory the piston is moving..very odd, I'll have a good look later

I have just replaced my original front discs & pads due to the inner face been heavily corroded,mine had done 45k & car is nearly 5 years old. 

Could be that the disks and inner pads are not properly matched (the pad is smaller than it should be), leaving an unswept area at the edge of the disk.  Not really a problem, but you won't get quite as much braking effort as you should.

or not cleaning the carriers properly when fitting new pads

I knew it wouldn't be the pads being wrong, that just doesn't happen... After stripping it all down it mostly caused by the carries not being cleaned! Simple basic tasks! Why do garages do it?!? 2 mins with the wire brush on the angle grinder and job done, nice and shine and the pads actually move now!! Also the dust shield on the passenger side has been removed, but pikey style! So a pair of new shields are being ordered and I think some heat will be required to get the old screws out, they are wedged!

If there evidence of bodgery, then who knows.  Lack of previous maintainence? 

Sliding calipers are the pits really.  If you look at the efforts the japannese factories made to get them to work properly on bikes, only to be forced to give up eventually.  In my experience they all end up being wonk sooner or later. Although VAG calipers do seem better than some.

Could be poor quality pad/disc, there's plenty of rubbish available if you are looking for cheapest.  

Wrong pad size would surely be evident on both inner and outer pad?

Could be too little braking as mentioned, or incorrect bedding in for that pad compound.  Once the pad glazes the disc, then it  is the devils own job to get through it by braking alone.

My 2008 Octavia with 40,000 miles got an advisory last year for a corroded inner surface on the front nearside disc.

 

It's just this week passed another MOT still on the same (original) brakes with no advisories.