rust on brake discs?

[Deleted member 49775]

Any idea whats the best way to get rid of rust???

 

[Slimy]

Temporarily? Go for a drive...

Permanently? Not possible. It's a drawback to having iron discs, they will go rusty. The only time you can avoid rust is to go for another compound, and I only know of ceramic as being an alternative...

 

[dangriff]

My rear discs are are 6 month old and heavy corroded on the friction face. ive tried putting the handbrake on whilst rolling dow hills etc to take the surface rust off but it seems to have gone too far already.
Just wondering if anyone else's discs are like this, the handbrake works but i wouldn't say it had a good bite, im thinking the rear calipers are not functioning properly

 

[RUM4MO]

My rear discs are are 6 month old and heavy corroded on the friction face. ive tried putting the handbrake on whilst rolling dow hills etc to take the surface rust off but it seems to have gone too far already.
Just wondering if anyone else's discs are like this, the handbrake works but i wouldn't say it had a good bite, im thinking the rear calipers are not functioning properly

I'd suspect that in its current state, the rear brakes will still be good enough to satisfy an MOT test as the rear braking requirement is lower than it used to be (I think). After all the salt has gone from the roads, if you use your car on longer faster journeys then you might end up with less rust. Once it really takes a hold though it tends to be harder than the friction material so when that point has been reached its new discs and pads time as skimming these discs would not be cost effective (I'd guess). Really this might also be getting caused by using the car only over short distances - no car has been designed with that use in mind.

Have or did you clean up the callipers when the discs were replaced?

 

[Slimy]

My rear discs are are 6 month old and heavy corroded on the friction face. ive tried putting the handbrake on whilst rolling dow hills etc to take the surface rust off but it seems to have gone too far already.
Just wondering if anyone else's discs are like this, the handbrake works but i wouldn't say it had a good bite, im thinking the rear calipers are not functioning properly

I wouldn't use the handbrake to clean them, it doesn't apply that much pressure. It's a mechanical ratchet rather than hydraulic pressure, no contest. Get it up to 70 then back down pretty sharpish. The discs only need one or two revolutions under hard braking to clean up.

If they don't clean up after that, then the calipers are struggling.

 

[KernowFR]

Mine are pretty much as described on a 58 plate 9k miler, and yes it looks bad and my rear calipers are working free, its just iron discs where the brakes are not used in anger all seem to go that way.

Tempted to try and get mine changed under warranty? i only got the car on saturday and saw then they were corroded.

 

[mazzerati]

Surely they should still clear even when your not thrashing it :S
otherwise what would be the point in having them if they don't work all the time Lol

 

[vngtx]

ive had 2nd hand discs and pads on that came with new brake setup, just went for a steady 5 mile drive at 30-40mph and they were good as new (for 2nd hand)

 

[mazzerati]

I think you rusty disc'd people should get them calipers checked out :S

 

[dangriff]

Im pretty sure my calipers are not putting down the pressure, it may be down to the fact that i rarely have more than one person in the car (i know some cars have rear swing arm position sensors to increase rear braking when you have a full load), im going to remove to calipers, clean them up, cycle the piston and check it for marks etc

 

[KernowFR]

Mine are free its just the car was used for very short trips and the young lady was very gentle on the brakes and washed it a lot

 

[RUM4MO]

Mine are free its just the car was used for very short trips and the young lady was very gentle on the brakes and washed it a lot

Yes, I exercise the brakes on my wife's Polo frequently as she seems to never need to use them in anger - so they end up getting glazed in winter and nicely polished in summer - I do mean exercise and not abuse!

 

[RUM4MO]

Im pretty sure my calipers are not putting down the pressure, it may be down to the fact that i rarely have more than one person in the car (i know some cars have rear swing arm position sensors to increase rear braking when you have a full load), im going to remove to calipers, clean them up, cycle the piston and check it for marks etc

I think that the load sensor nowadays is the ABS module, "cycle the piston" do you mean to extend it so that you can clean it up? Watch out for it poping right out. Maybe rewind it fully, clean up the calliper and use the correct procedure for forcing it to readjust the handbrake bit.

 

[ss55eat]

I've had this same problem on a MK2 Ibiza Cupra and my current MK4 Cupra. In both cases I swapped the rear discs for some plain Brembo ones from German & Swedish and never had a problem since. I think its the quality of the OEM discs; maybe they are a bit too hard.

 

[RUM4MO]

I've had this same problem on a MK2 Ibiza Cupra and my current MK4 Cupra. In both cases I swapped the rear discs for some plain Brembo ones from German & Swedish and never had a problem since. I think its the quality of the OEM discs; maybe they are a bit too hard.

I have never thought that German cars had discs that were too hard, remember that us in UK used to get very grumpy if the discs did not last at least as long as the car! (I'm quite old!). I'm quite happy to have discs that wear along with the pads and maybe change them both at the same time - I've done that with the B5 Passat and wife's 9N Polo - okay maybe the disc thickness is the issue at the front and rust the issue with the under used rear. I think there is some freedom of thought as to the exact "mix" of the material used and so some will be better than others in more than one aspect - and Brembo are proper brake people. Factory fit will be as usual adequate and cheapest - which does mean that they are not what some of us would like if we had a choice - I missed changing to Brembo (just) and went for ATE from ECP - cheap but safe enough!