Rust on brake discs

[Lord Voltermore]

My  new car has been sitting unused in the rain for a few days and the brake disc rotors have picked up some surface rust.  I have taken it for a short run specially to de rust the brakes.

  A good way of doing this on a  mk4 is to apply the electric handbrake with your finger whilst on the move.  Chose somewhere  safe. Initially the effect is slight,but rapidly becomes much more powerful. All that power just from my finger       If you release your finger before the car stops the brakes will release automatically.    I think its a good idea to experience this effect. They are potentially your emergency brakes.   

I sometimes neglected to do this on my previous car. After 3 years the brake rotor discs always looked a bit brown , possibly from rust dust being imbedded in slight pitting.   They were still quite shiny, and effective and passed the MOT.

Is it only me this happens to ? I  sometimes see parked cars with superficial light rusting  but most seem to have nice silver shiny discs .    Yet all my cars  have tended to get  rusty brakes, with darker coloured discs .None ever failed the MOT.    Different makes of car and in some cases both before and after the discs being replaced.        Maybe its because I am usually gentle with the brakes.  (Heavy braking is a failure to anticipate     )

[5thcivic]

I don't do really long trips often, so am in B mode a lot, so do not use a lot of brakes except for stopping at already creeping speed, and this does happen. I apply brake and accel at the same time sometimes when no one is around to give them a clean, I must try your handbrake trick.

[embee]

The OE discs on my mk.3 do rust at the least hint of dampness. I tend not to use the Jazz over frequently,  I have another run around,  though when I do drive it it's usually quite long runs which do clean the discs fairly effectively.
To minimise rust while the car stands I bought a set of wheel covers which help a lot.  They are an excellent fit and very easy to fit,  just slip them over the top of the wheel and smooth down and round. They haven't blown loose so far. Just slip them up and off again.
Cost was around £40 from a company in the north of England,  Carcovers.co.uk. I have the size 14 to 16" wheels for 185/60 -15 tyres.

[Kremmen]

I've always found that normal driving and braking soon shifts any surface rust from washing or rain

[Karoq]

No need to mess about with the EPB. just apply the foot brake gently for a few yards.
You can control the footbrake pressure much more easily than the EPB.

[davejazz]

I've always found that normal driving and braking soon shifts any surface rust from washing or rain

I am with Lord V on this one, seeing my brown brakes through the spokes. Not pretty! I also use my brakes very little, hoping that I read the road ahead. I have not used the “handbrake on the move tip yet”, I don’t want flat bits on the tyres! Ha!

My way of reducing excess rust, is to use a steepish hill; build up the speed to perhaps 50 mph, move the stick into neutral, and rest on the brakes to the bottom. By doing it this way, the clever electronics, are not putting this gravitational energy, into charging the battery,

Two final points,…I hope gravitational is a word, as it’s a first for me; and don’t forget to put your car in “Drive”, for your onward journey!

Continue enjoying your Jazz.

[Jazzik]

No need to mess about with the EPB. just apply the foot brake gently for a few yards.
You can control the footbrake pressure much more easily than the EPB.

Just applying the foot brake gently for a few yards will not effectively (or better: not at all) remove rust from all 4 brake discs.
When braking gently with the e:HEV, the mechanical brakes are not activated at all, except for the last few meters before coming to a full stop. And when braking slightly less gentle, probably only the front brakes will work.

Here https://clubjazz.org/forum/index.php?action=dlattach;topic=16448.0;attach=10709 you can read that all four brakes are applied with the handbrake and therefore all 4 discs will be cleaned.

[Tombola]

I've always found that normal driving and braking soon shifts any surface rust from washing or rain

 

My way of reducing excess rust, is to use a steepish hill; build up the speed to perhaps 50 mph, move the stick into neutral, and rest on the brakes to the bottom. By doing it this way, the clever electronics, are not putting this gravitational energy, into charging the battery,

I am under the impression that coasting in neutral is not advisable with an Auto transmission 

[Lord Voltermore]

You shouldnt coast in neutral. There is no need and I think its technically regarded as not in proper control of the vehicle.  But the same may be said of using the electric handbrake   

BTW applying  the handbrake  whilst on the move applies all 4 brakes. I hope someone will correct me if I am wrong but I think  it activates the electric  brake  servo used for abs via the hydraulics  . And thus provides an independent backup to brake pedal failure . The rear brakes can also be applied by the electric callipers, so presumably this is a third backup in the unlikely event of total hydraulic failure.

I dont think the brake simulator problem  causes brake to fail completely while on the move.. Just lots of warning lights and No go.  Which is why Honda have been able to drag their heels on a recall.

I agree you can derust your brakes just using  the footbrake.  But i found it useful experiencing the affect of using the handbrake.  I am now confident of being able to stop the car in an emergency.   You can get quite powerful stopping power. After trying it a few times I started to get motion sick

[coldstart]

You shouldnt coast in neutral. There is no need  ....

What makes you think this?

Coasting is one of the favourite methods of "normal" automatic gears (they do it without you being aware of it).
So: What's good for the goose...

[davejazz]

Love to see the different options for shining up the discs.

I still think that coasting downhill in neutral, with a bit of foot brake, works best for me.

Got to go now,…. I’m working on a new thread, involving wire wool!

[ninanina]

I only have to not drive my Prius for a couple of days and the discs are definitely a bit rusty so don’t think it’s anything unusual

I expect the same thing to happen when I get my Jazz, hopefully tomorrow

This time of year it’s a bit moist so it’s to be expected I guess

[Kremmen]

I'm puzzled

On many occasions, after washing the car and an overnight stand, my discs all had surface rust

At the end of my driveway I could feel and hear the grinding when coming to a stop

2 miles down the road was my Monday morning petrol station, at the end of a 50mph dual carriageway. I probably only had to lightly brake about 3 or 4 times to get there

But, when I got out of the car and looked at the brakes they were all shiny again

No need for any special braking
 

[Nicksey]

I'm puzzled

On many occasions, after washing the car and an overnight stand, my discs all had surface rust

At the end of my driveway I could feel and hear the grinding when coming to a stop

2 miles down the road was my Monday morning petrol station, at the end of a 50mph dual carriageway. I probably only had to lightly brake about 3 or 4 times to get there

But, when I got out of the car and looked at the brakes they were all shiny again

No need for any special braking

Ditto. All the Renaults I had prior to the Jazz did exactly the same... albeit they only had front discs, the rears were always drum (which incidentally, the outer cases all developed a kind of fine rust patina that made the grey/silver paint coating look very tired. This was virtually impossible to clean too unless you removed the wheel).

[Kremmen]

My amateur theory is that because when released the brake pads are still very close to the disc, I wonder if there is sufficient heat build up, albeit tiny, to dissipate the rust

Answers on a postcard .......