Sanding brake discs ***resolved*** - Renault Forums :: Independent Renault forum

Brakes/Hubs Brakes, Hubs, and etc

LinkBack Thread Tools Display Modes
post #1 of 64 (permalink) Old 4th March 2013 Thread Starter
Diamond member
Mouse Race Champion, UFO Shoot Out Champion
MadScenic's Avatar
Join Date: Nov 2011
Posts: 115
Nominated 0 Times in 0 Posts
TOTW/F/M Award(s): 0
Thanks: 28
Thanked 21 Times in 19 Posts
Sanding brake discs ***resolved***

Hi all,

I went for the yearly technical check (like the UK MOT) in the country where I live (Austria) at the weekend. The test took place at a branch of Austria's national car club (like the AA) where they are generally overprecise when it comes to the MOT, but give you an objective opinion because they don't do repairs themselves and so don't try to rip you off. That's the theory anyway.

Anyway, one of the several problems with the car was "excessive corrosion" of a front brake disc, supposedly because the car had been left standing too long during the winter.

According to the examiner, I don't need to replace the whole brake disc, just take it off and sand it down till the rust is gone. Presumably there is some pitting.

- Has anyone ever heard of this practice before?

- Would you pass the MOT in the UK or the equivalent in any other country after sanding away the rust?

- Can't I just do a few emergency stops instead of sanding down the brake disc?

Currently in MadScenic's garage:
1999 Scenic Mk I Phase I 1.4 16v

Last edited by VelSatisfied; 20th March 2013 at 09:53 AM.
MadScenic is offline  
  5 Lastest Threads by MadScenic
Thread Forum Last Poster Replies Views Last Post
MOT - 3 issues with brakes Brakes/Hubs ste2425 2 535 2nd March 2015 08:35 AM
Scenic Central Locking Issue Electronics MadScenic 12 2935 4th December 2014 10:47 AM
Oil leak on rocker cover Engines MadScenic 8 3296 6th April 2013 04:54 PM
Main dealer secretive about part numbers General Chat Magners 8 1987 30th March 2013 10:34 PM
Corroded brake line - replace only corroded part?... Brakes/Hubs MadScenic 7 2363 4th March 2013 11:09 AM
Sponsored Links
post #2 of 64 (permalink) Old 4th March 2013
Platinum member
coup's Avatar
Join Date: Jul 2011
Posts: 6,341
Nominated 6 Times in 17 Posts
Nominated TOTW/F/M Award(s): 5
Thanks: 860
Thanked 1,153 Times in 1,014 Posts
Re: Sanding brake discs

Austria must be a lil more lenient,or is it stricter than Germany,their MoT is supposed to be really hard..

So it "failed" on the disc,or was it an advisory?

Ive never heard of anything like that,
You probably know yourself.
If its very light rusting that you get even from washing the car and letting it stand for a day or 2 the brake action should clear it after a lil while.
If its really pitted in spots Id imagine the disc would have to come off and get "shaved down on some kind of lathe?,otherwise you might leave depressions from sanding spots.

Currently in coup's garage:
RM III coupe 1.5dci FVT,Audi TT Mk1 ,a bike and too much rubbish.
coup is offline  
post #3 of 64 (permalink) Old 4th March 2013
Banned User
Curveball Champion
hondo's Avatar
Join Date: Sep 2005
Posts: 30,768
Nominated 9 Times in 16 Posts
Nominated TOTW/F/M Award(s): 10
Thanks: 1,929
Thanked 3,511 Times in 2,879 Posts
Re: Sanding brake discs

If it's just the extreme outer edge of the perimeter of the disk I'd remove this with a sander. however I'd not be doing any of that, well not on the disks braking area.

Like you say, if you can run the car for a while the friction of the pads hopefully will remove it..

Mind you, don't get pulled over by the Plod, while doing it.
Currently in hondo's garage:
1.6 Valve-Matic SR. Red hot, toasty feet.
hondo is offline  
post #4 of 64 (permalink) Old 4th March 2013 Thread Starter
Diamond member
Mouse Race Champion, UFO Shoot Out Champion Threadstarter
MadScenic's Avatar
Join Date: Nov 2011
Posts: 115
Nominated 0 Times in 0 Posts
TOTW/F/M Award(s): 0
Thanks: 28
Thanked 21 Times in 19 Posts
Re: Sanding brake discs

Hi coup, thanks for the reply.

It failed on the disc, among other things (nearly all corrosion related )

How strict the MOT here is depends purely on the examiner. The place I went there appears to be very strict and at one point there were three mechanics all discussing the rusted brake line (see the other thread I made in this forum).

I can only assume it's not that bad if he said you can sand it off, but at the same time it was bad enough to fail (these people are quite strict and put nearly everything down as a fail). I have never heard of this before, which is why I am asking.

And you make a good point and it's something I also thought - you can't do it by hand because the sanding wouldn't be even around the surface of the disc.
Currently in MadScenic's garage:
1999 Scenic Mk I Phase I 1.4 16v
MadScenic is offline  
post #5 of 64 (permalink) Old 4th March 2013
S.M.A.R.T.(y) Pants
VelSatisfied's Avatar
Join Date: Jul 2006
Posts: 16,938
Nominated 11 Times in 37 Posts
Nominated TOTW/F/M Award(s): 17
Thanks: 4,551
Thanked 2,471 Times in 1,852 Posts
Re: Sanding brake discs

As long as the pads mate and line-up with the disc correctly, then they should erode any corrosion after a few stops.

I can understand that a roughened and unstable corroded surface may end-up giving a brake performance which is a bit unpredictable and 'snatchy' as a result.

If you are going down the grinding & milling route, you really would need a lathe to ensure it's all correct.



This job should never be complete - the day I think I've done it all, is the day I resign.

S.M.A.R.T. Technician
Currently in VelSatisfied's garage:
2005 FIAT Ducato 2.8JTD LWB Gran Volume, 2000 Kawasaki ZZR 1100 D7 'fullpower' in black + full GIVI & KAPPA luggage, 2007 MB R-Class 320 CDi Sport LWB uprated by Brabus to 300Bhp don't know if there's a 155mph limiter - will be fun finding out! 2004 Mercedes Vaneo 1.7 CDi Ambiente 7-seater
VelSatisfied is offline  

brake , discs , resolved , sanding

Quick Reply

Register Now

In order to be able to post messages on the Renault Forums :: Independent Renault forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome