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    Steel brakes: how to prevent brown dust forming?

    I have the stainless steel brakes with red calipers on my 997S. The car is nearly 2 months old with around 1300 miles on the odometer.

    Every time I wash it or if I park after driving in rain, I take it for a few short (slow) laps in my underground car park repeatedly braking quite hard just to dry out the brakes.

    I once forgot to do this and within 2 days I saw a thin layer of brown dust form on my brake discs. I took it for a few short slow laps again in the car park and the thin layer of brown dust again disappeared so that the brake discs look like new again. (It can't be rust since it hasn't penetrated the surface).

    My question is: why do Porsche stainless steel brakes discolour so easily? How should one maintain them so that they last? Is this what all of you have to do to look after the discs? (Makes me feel sad that I live in a cold, damp country! )

    Is the 'gunk' that people talk about, the brown dust which oozes out of the holes drilled in the discs or is it something else?

    [BTW, PCCBs were not an option for me]

    Are there any previous threads on this subject? I tried searching - little joy...

    Grateful for any advice/input Thanks!

    (Sheesh, my 2000th post...)

    Re: Steel brakes: how to prevent brown dust forming?

    1. Your rotors are not stainless steel, the pistons inside your calipers likely are though...

    2. That brown powder is simply surface rust. Totally harmless unless you left your car parked without driving it once for several years in a damp environment.

    3. The dust coming out of the holes in the rotor is primarily accumulated brake pad dust, not the rust that grows on the bare surfaces of your rotors. You're looking at two different "dusts" that are not related.

    Every time I wash my car, the next day when I go to drive it, the rotors are brownish-red with surface rust. This does not cause "pitting", you're not going to pit that hardened steel overnight... It's primarily topical..

    HOWEVER, I've also experimented with driving my car around my neighborhood right after washing to dry-out the brakes. From a CLEANLINESS standpoint, I find that strategy creates a far BIGGER mess than simply pulling my car into it's garage spot and allowing it to air-dry overnight. If I drive the car around right after I wash it, a wet nasty slurry of water and brake dust flings EVERYWHERE as I drive the car around "drying the brakes", which causes me to have to hand-clean my wheels inside and out all over again. What a pain in the arse...

    But if I simply allow the car to air-dry overnight, I come out in the morning with squeeky-clean and detailed wheels, and a thin layer of surface rust on the rotors... BUT IT'S ALL DRY. That way, I pull out of the driveway, and after a few applications of the brakes leaving the neighborhood, the rotors are clean, and the wheels are clean also, because when the dry pads clamp down against the rust-covered rotors, it basically makes the rust go "poof" into airborne-dust that just blows away in the wake of the car...

    Re: Steel brakes: how to prevent brown dust forming?

    My Lotus has never driven through any patch of water or been washed while the rotors were hot. They still look brand new. Basically, the moment the rotors go into contact with any form of water while warm will cause them to do this.

    Re: Steel brakes: how to prevent brown dust forming?

    Rust only needs humid air. Keeping it out of water is not the anwser but it would be funny to watch someone try! LOL
    My PCCB brakes never have this problem (I know, not an option) and there is very little if any brake dust. It's nice to always have clean wheels.

    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    69bossnine said:
    HOWEVER, I've also experimented with driving my car around my neighborhood right after washing to dry-out the brakes. From a CLEANLINESS standpoint, I find that strategy creates a far BIGGER mess than simply pulling my car into it's garage spot and allowing it to air-dry overnight. If I drive the car around right after I wash it, a wet nasty slurry of water and brake dust flings EVERYWHERE as I drive the car around "drying the brakes", which causes me to have to hand-clean my wheels inside and out all over again. What a pain in the arse...

    But if I simply allow the car to air-dry overnight, I come out in the morning with squeeky-clean and detailed wheels, and a thin layer of surface rust on the rotors... BUT IT'S ALL DRY. That way, I pull out of the driveway, and after a few applications of the brakes leaving the neighborhood, the rotors are clean, and the wheels are clean also, because when the dry pads clamp down against the rust-covered rotors, it basically makes the rust go "poof" into airborne-dust that just blows away in the wake of the car...



    Exactly same experience over here. If you don't wash your car at home and want to avoid the double cleaning work, make sure to drive home in Grandpa style with very gentle braking only

    Re: Steel brakes: how to prevent brown dust forming?

    I have this theory that, at first, most of dust accumulates in the rotors and doesn't reach the wheels. Then it gets to a point inside the rotors where any new dust goes directly to the rims.

    So when cleaning the rotors I use compressed air (and wear a dust mask) to get EVERY last bit of dust out. I can't see using a garden hose and accomplishing the same level of thoroughness. Therefore your wheels will stay cleaner longer if you use compressed air before or instead of gardenhose.

    Because of compressed air I believe I have a whole lot less wet muck hitting the rims when driving to dry brakes after a wash. All I have to do is get in there with a cloth and wipe what little accumulates with a cloth.


    Re: Steel brakes: how to prevent brown dust forming?

    I must admit that I'm not going mad about drying the brakes after washing for this very same reason - I'm glad it's not just me! I feel guilty about it though - I thought it was best to dry out the water from the vented discs to stop them rusting too badly? However I do drive mine pretty much every day - it never gets washed and then immediately stored for weeks without driving.

    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    Mike S said:
    My Lotus has never driven through any patch of water or been washed while the rotors were hot. They still look brand new. Basically, the moment the rotors go into contact with any form of water while warm will cause them to do this.


    I think the Lotus rotors are Aluminum (which doesn't rust like Iron - those have a lower thermal capacity - ok with the light weight of the Elise/Exige)

    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    69bossnine said:
    1. Your rotors are not stainless steel, the pistons inside your calipers likely are though...

    2. That brown powder is simply surface rust. Totally harmless unless you left your car parked without driving it once for several years in a damp environment.

    3. The dust coming out of the holes in the rotor is primarily accumulated brake pad dust, not the rust that grows on the bare surfaces of your rotors. You're looking at two different "dusts" that are not related.

    Every time I wash my car, the next day when I go to drive it, the rotors are brownish-red with surface rust. This does not cause "pitting", you're not going to pit that hardened steel overnight... It's primarily topical..

    HOWEVER, I've also experimented with driving my car around my neighborhood right after washing to dry-out the brakes. From a CLEANLINESS standpoint, I find that strategy creates a far BIGGER mess than simply pulling my car into it's garage spot and allowing it to air-dry overnight. If I drive the car around right after I wash it, a wet nasty slurry of water and brake dust flings EVERYWHERE as I drive the car around "drying the brakes", which causes me to have to hand-clean my wheels inside and out all over again. What a pain in the arse...

    But if I simply allow the car to air-dry overnight, I come out in the morning with squeeky-clean and detailed wheels, and a thin layer of surface rust on the rotors... BUT IT'S ALL DRY. That way, I pull out of the driveway, and after a few applications of the brakes leaving the neighborhood, the rotors are clean, and the wheels are clean also, because when the dry pads clamp down against the rust-covered rotors, it basically makes the rust go "poof" into airborne-dust that just blows away in the wake of the car...




    Same exact here too. And the problem is even if you take the car out for a quick spin to sling out all the dirty water from the discs trying to get the inside of the rims clean again without spraying water back into the wheel/brakes creates a freakin dirty mess on towels/ hands and doesn't get the rims looking as good as they were and is more abrasive on the wheels finish then using a hose & lots of soapy water. Plus to do it right you have to clean the inside of the wheel, then move the car enough to get the rest of the wheels inside. It doesn't sound like a big deal until you've done it a dozen times. I've used air to blow out the discs but you still get the same mess. Washing the car and then letting it sit without driving it works best but then there's still the dry rust that falls into the rims the next day, not really noticeable but it's there. And there's been times where I would have liked to wash the car and go someplace without having to go around the block, come back home just to clean the wheels again. Just cleaning the wheels/ brake assemblies in the first place from all the brake gunk is a real PITA. It takes me longer to get the calipers/disc hubs/ wheels clean than it does the entire rest of the car!!! Never again. Cleaning the wheels on my F430 w/ CCM's is such a pleasure. No rusty/ dirty water& crud and no rust to accumulate of the huds. I really don't think I'll ever order another sports car w/ steel brakes.

    Re: Steel brakes: how to prevent brown dust forming?

    Agree with everything said. The rotors are actually fairly poor quality steel - they are a consumable after all (i.e. they wear out and need replacing after a bit) and so get rusty pretty easily.

    I tend to drive the car after washing, only because a) I wash the car at a jet wash in winter at least and b) I once washed the car after a salty winter drive and left it - for two weeks. Result? Pads bonded to the discs, with the resulting (fictional) "warping" judder when I braked. The OPC tried to get me to pay $$$ for new front rotors and I said "no way I've only just bought the car". So I did some digging, found out that it's about the pad material and basically thrashed the arse of the car over a couple of days along some back road twisties - and no more judder. Good fun, too!

    Cheers,

    SoS.

    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    SonOfStig said:
    Agree with everything said. The rotors are actually fairly poor quality steel - they are a consumable after all (i.e. they wear out and need replacing after a bit) and so get rusty pretty easily.

    I tend to drive the car after washing, only because a) I wash the car at a jet wash in winter at least and b) I once washed the car after a salty winter drive and left it - for two weeks. Result? Pads bonded to the discs, with the resulting (fictional) "warping" judder when I braked. The OPC tried to get me to pay $$$ for new front rotors and I said "no way I've only just bought the car". So I did some digging, found out that it's about the pad material and basically thrashed the arse of the car over a couple of days along some back road twisties - and no more judder. Good fun, too!

    Cheers,

    SoS.



    I had the same friggin problem one time where my pads glued to the rotor, and once broken loose, left behind a residue that caused a shudder/kick in the pedal. How did I fix it? Not by running the snot out of my brakes, it scrubbed clean with a Scotch-Brite pad...

    Re: Steel brakes: how to prevent brown dust forming?

    After washing the wheels I use a hose pipe to spray the discs to get rid of all the brake dust that can get in the holes drilled in the discs, then immediately dry them using a powerful leaf-blower. Never park the car with the handbrake on after washing if possible.

    Re: Steel brakes: how to prevent brown dust forming?

    I wondered if taking the discs off and using some "rust preventer" within the cavities between each skin would work. But not sure if this would invalidate warranties etc and perhaps cause issues with an insurance claim?

    Re: Steel brakes: how to prevent brown dust forming?

    Move to the desert. Never wash your car. It's unavoidable.

    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    Grant said:
    Quote:
    Mike S said:
    My Lotus has never driven through any patch of water or been washed while the rotors were hot. They still look brand new. Basically, the moment the rotors go into contact with any form of water while warm will cause them to do this.


    I think the Lotus rotors are Aluminum (which doesn't rust like Iron - those have a lower thermal capacity - ok with the light weight of the Elise/Exige)



    Hi Grant,

    I have seen other Exige's/Elise's with "rusted" rotors after a wash. I don't drive the Exige in the rain because of the semi-slicks and no traction control. I don't want to try my luck

    Will take a pic later today and show you

    Re: Steel brakes: how to prevent brown dust forming?

    Here is the 997's rotors, you can clearly see at the top it has rust as spoken of.

    Re: Steel brakes: how to prevent brown dust forming?

    Ceramics, no problems

    Re: Steel brakes: how to prevent brown dust forming?

    Here is what I meant by the Lotus' wheel never getting wet while warm.

    Re: Steel brakes: how to prevent brown dust forming?

    Squeegy clean after 2600 miles on the track.

    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    Mike S said:
    Here is the 997's rotors, you can clearly see at the top it has rust as spoken of.



    I see what you mean. wow.

    My us$.02:

    Don't use wheel cleaner; it is most likely a hydroxide and caustic and probably cleans the steel a bit too well. Maybe that's allowing the accumulation of rust.

    Just a little detergent on the wheels has always been enough for me; tar and sap remover for road tar (I never use wheel cleaner).

    Try to forget about the rust. I wouldn't "treat" in in any way; they're your brakes! No paint, no, rust remover, just maybe a wire brush to get excess rust off and then no more wheel cleaner.


    Re: Steel brakes: how to prevent brown dust forming?

    Quote:
    MMD said:
    Quote:
    Mike S said:
    Here is the 997's rotors, you can clearly see at the top it has rust as spoken of.



    I see what you mean. wow.

    My us$.02:

    Don't use wheel cleaner; it is most likely a hydroxide and caustic and probably cleans the steel a bit too well. Maybe that's allowing the accumulation of rust.

    Just a little detergent on the wheels has always been enough for me; tar and sap remover for road tar (I never use wheel cleaner).

    Try to forget about the rust. I wouldn't "treat" in in any way; they're your brakes! No paint, no, rust remover, just maybe a wire brush to get excess rust off and then no more wheel cleaner.





    Hi MMD,

    I don't think it's the wheel cleaner either, although it may contribute to the acceleration of rust once it has taken place... I use wheel cleaner on my Lotus all the time, it's still the way it looked from day 1! I really think coming into contact with water while they are hot is the main factor.

    Re: Steel brakes: how to prevent brown dust forming?

    Thanks very much for all your responses guys Much appreciated.

    After reading your posts, this seems to be where I have reached:

    My main concerns (which you have collectively put to rest, especially 69bossnine) were this: have I been doing something wrong for the brown dust to form and is it harmful to the discs? The answer is no on both fronts.

    So this then raises the issue of how to deal with wet brake discs. Either (a) use a leaf blower, (b) dry the discs by driving (BUT this creates slurry) or (c) let them air-dry then use the brakes the next day so that the pads will wipe off the brown dust. I don't want to use a leaf blower nor do I want to clean slurry nor do I plan to clean the brakes/wheels twice. Once is time-consuming enough!

    I think I will do the following: I will dry the brakes a little by driving (because this causes somewhat less quantity of brown dust to form and reduces the phenomenon of the brake pads sticking to the discs) but not too much so that very little slurry forms but I will mainly rely on using the brakes the next day so that the pads wipe away the brown dust.

    Whatever happens, I won't leave the discs after a wash for more than 1 day without using the brakes so that the rust doesn't become serious. Certainly I won't wash the car and then leave the discs for a week or two. That seems like murder on the discs.

    I will also not use the handbrake after washing only (because it does feel attached the next day if I leave it applied when the car has been washed). The only issue is that I need to stop the car from rolling. I plan to leave the car in gear to stop this. Is this safe? I assume so.

    Thanks again for all the input. Any further thoughts welcome. Have a great weekend.

    Re: Steel brakes: how to prevent brown dust forming?

    If you clean the wheels without flushing the rotors and you get sufficient water on the rotors, it will cause a slurry of brake dust that will drip out of the rotor and onto the inside of the wheels. I prefer using water, because air spreads the dust onto other parts of the car and possibly into my lungs. My process is wash to outer face and spokes of wheel using a soft bristle, long-handled brush and a smaller brush with a round head to clean the openings at either end of the spokes. I don't wash the rear spacing or inner circumference of the wheel yet. Next, I flush the rotors using the high pressure setting on the hose nozzle directed right into the holes in the rotor. I DO NOT PUT WATER ON THE ROTORS IF THEY HAVE ANY HEAT IN THEM! I do all four rotors, and then roll the car far enough to expose the area of the rotor that was covered by the caliper to ensure the entire rotor is flushed. This will flush most of the slurry from inside the rotor. Then I drive a short distance to sling any remaining slurry and use the brakes enough to heat up the rotors to prevent surface rust. Then I use the long handled soft bristle brush to wash the inner circumference of the wheels being careful not to get water on the rotors -unless I know I will be driving soon. Next, I wash the car itself which takes less time than the wheels!

    Re: Steel brakes: how to prevent brown dust formin

    I just wanted to state the obvious; everytime you wash your car you should drive it to centrifically expell water from wheels and rotors (also dry pads and rotors by braking). I ALWAYS plan to do this immediately after washing/drying car: no rust.

    Re: Steel brakes: how to prevent brown dust formin

    God - you all make it so complicated.

    Just wash the thing and let it go - the rust comes off after a few stabs on the brakes. I've never seen any slurry to speak of.

    Easy - at this time of the year it's always raining in the UK, so no point in letting it dry. Just wash it once a week and leave the finer points till Spring.

    Re: Steel brakes: how to prevent brown dust formin

    Quote:
    John H said:
    God - you all make it so complicated.

    Just wash the thing and let it go



    John,,dont talk about your baby like that ..

    Lads,,what about using a hairdryer (you do already dont you )

     
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