rusty discs - how rusty is normal?

a few months ago i switched out the entire front brake system- heavily
scored discs, beat pads, and frozen calipers were replaced with cheap
autozone discs and pads, and rebuilt calipers.

now, if i dont drive every day, the disc surfaces rust visibly, and
make an obvious grinding noise the first few times i use the brakes.
the breaking is smooth and strong, as far as i can tell. i have never
driven any other car whose brakes rusted so quickly, though. two days
of sitting around, and the grinding is back.

the discs, on a quick inspection, look fine. no scoring to speak of.

i could return them and upgrade to a pricier disc most likely. the
grinding for the first couple times braking doesnt bother me. i just
dont want any surprises after the 'warranty' runs out.
anything i shoudl know?

thanks for the advice,
anthony

On 19 Jan 2005 18:28:28 -0800, "ant" >
wrote:

>a few months ago i switched out the entire front brake system- heavily
>scored discs, beat pads, and frozen calipers were replaced with cheap
>autozone discs and pads, and rebuilt calipers.
>
>now, if i dont drive every day, the disc surfaces rust visibly, and
>make an obvious grinding noise the first few times i use the brakes.
>the breaking is smooth and strong, as far as i can tell. i have never
>driven any other car whose brakes rusted so quickly, though. two days
>of sitting around, and the grinding is back.
>
>the discs, on a quick inspection, look fine. no scoring to speak of.
>
>i could return them and upgrade to a pricier disc most likely. the
>grinding for the first couple times braking doesnt bother me. i just
>dont want any surprises after the 'warranty' runs out.
>anything i shoudl know?
>
>thanks for the advice,
>anthony

That is ABnormal.

The difference between pig iron and steel.

Lg

ant > wrote in message
oups.com...
> a few months ago i switched out the entire front brake system- heavily
> scored discs, beat pads, and frozen calipers were replaced with cheap
> autozone discs and pads, and rebuilt calipers.
>
> now, if i dont drive every day, the disc surfaces rust visibly, and
> make an obvious grinding noise the first few times i use the brakes.
> the breaking is smooth and strong, as far as i can tell. i have never
> driven any other car whose brakes rusted so quickly, though. two days
> of sitting around, and the grinding is back.
>
> the discs, on a quick inspection, look fine. no scoring to speak of.
>
> i could return them and upgrade to a pricier disc most likely. the
> grinding for the first couple times braking doesnt bother me. i just
> dont want any surprises after the 'warranty' runs out.
> anything i shoudl know?
>
> thanks for the advice,
> anthony

Nothing to worry about. Discs are all made of cast iron (except for a few
oddballs and motorbike discs) but the exact mix of the iron is going to
differ between different foundries and manufacturers or even just different
casting batches from the same place. It only takes tiny changes in the
amount of alloying elements like chromium to change the corrosion behaviour
quite significantly. The OE discs on my Ford Focus rust fairly quickly and
the ones on the Ford Mondeo before it didn't. They both work equally well
after the initial brake application though and yours aren't suddenly going
to wear out or fail. In drier weather it'll probably stop happening anyway.

--
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)

ant wrote:

> now, if i dont drive every day, the disc surfaces rust visibly, and
> make an obvious grinding noise the first few times i use the brakes.
> the breaking is smooth and strong, as far as i can tell. i have never
> driven any other car whose brakes rusted so quickly, though.

Every day, I park near the same co-workers. One has a C5 'vette another
an Infiniti GXmumblesomethingwhatever (about 9 months old), another a GM
F-body. All 3 have very open wheels that make the rotors visible, and
all 3 will show visible surface-rust spots by *noon* after being parked
in the morning on a rainy day. And this is in the south- no salted roads
within 500 miles. If I look very carefully through my own wheels, my old
'73 Plymouth shows the same surface rust, and one of its rotors is
original to the car with over 400,000 miles on it. Any bare iron surface
will show light rusting within hours in damp weather- whether or not its
a problem depends on how deep the rust penetrates.

The grinding is a little bit of a concern, though. How deep does the
rusting appear to penetrate the surface? If you can just wipe it off
with your finger tip, don't worry.

In article .com>,
says...
>
>
>a few months ago i switched out the entire front brake system- heavily
>scored discs, beat pads, and frozen calipers were replaced with cheap
>autozone discs and pads, and rebuilt calipers.
>
>now, if i dont drive every day, the disc surfaces rust visibly, and
>make an obvious grinding noise the first few times i use the brakes.
>the breaking is smooth and strong, as far as i can tell. i have never
>driven any other car whose brakes rusted so quickly, though. two days
>of sitting around, and the grinding is back.
>
>the discs, on a quick inspection, look fine. no scoring to speak of.
>
>i could return them and upgrade to a pricier disc most likely. the
>grinding for the first couple times braking doesnt bother me. i just
>dont want any surprises after the 'warranty' runs out.
>anything i shoudl know?

Nothing to worry about.
-----------
Alex

Steve wrote:
> The grinding is a little bit of a concern, though. How deep does the
> rusting appear to penetrate the surface? If you can just wipe it off
> with your finger tip, don't worry.

i had a peek at it this afternoon. didnt take the wheel cover off, or
really mess around, but i did tickle the disc with a finger and it
feels smooth as the day i put it on. ill have another look another day
(when the car isnt covered with snow..) and assuming theyre both like
that ill just learn to love my scratchy first brake application.

speaking of rust- the rebuilt caliper i put on is now very rusted, on
the surface. im not worried about looks, but i dont want anything to
seize up inside like the old calipers. does anyone treat their metal
parts with anything? spray it down with a light oil? silicone the boots
or anything?

anthony

TeGGer® wrote:

> "ant" > wrote in
> oups.com:
>
>
>
>>speaking of rust- the rebuilt caliper i put on is now very rusted, on
>>the surface. im not worried about looks, but i dont want anything to
>>seize up inside like the old calipers. does anyone treat their metal
>>parts with anything? spray it down with a light oil? silicone the boots
>>or anything?
>
>
>
>
> Probably the best thing you can do is to give the piston some silicone
> grease all around its circumference.
>
> Pump the pedal with the caliper off the rotor until the piston's dust boot
> is pretty much extended. Get some spray brake cleaner, wash off all the
> dirt from the dust boot where it meets the piston.
>
> Then use something like this:
> http://www.tegger.com/hondafaq/rustybrakes/syringe.jpg
> to inject silicone under the dust boot all around the piston. Now push the
> piston back in and work it in and out a few times to distribute the
> silicone. This will help keep your pistons from seizing for a long time.
>
> As for the rest of the servicing,
> http://www.tegger.com/hondafaq/rusty...rakeintro.html
> or if you live in a dry area,
> http://www.g2ic.com/tegtips/brakesus/5.html
>
>

I also paint any new calipers. Hose 'em down with brakleen to get the
grease off, then a final wipe with windex (really!) then paint. I just
throw a light coat of engine paint on there, it really makes a
difference and holds up reasonably well. Some will say that that hurts
the abilities of the caliper to shed heat but if that is a concern to
you you should be looking into special coatings and probably brake upgrades.

I also put a turn of teflon pipe tape on the bleeder screw threads (but
NOT the seat area) as well as a vacuum cap over the bleeder screw's
nipple, if the car doesn't have a little cap from the factory. Nothing
sucks worse than a perfectly good caliper that has to be replaced
because of a frozen bleeder. Of course, you are changing your brake
fluid at least every 2 years right?

Finally, I put a little anti-seize on the backs of the pads, to prevent
squeaking and I also knock a little chamfer on the leading edge of the
pads. My 944's brakes used to make all sorts of noise, especially after
going through a car wash... today was the first day I took the car
through a car wash after going through my "de-squeak" procedure and the
brakes were dead silent. Some people like the anti-squeak shims, but I
always have a bottle of anti-seize handy anyway so it's easier for me to
use that.

I like the idea of something inside the dust boot to prevent rust, all
my old manuals suggest something called "brake assembly paste" which I
believe is pretty much silicone grease, but when I ask for it at the
parts store I get blank looks... and the little tubes of dielectric are
too expensive to use on brakes...

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

In article >,
Nate Nagel > wrote:

> I like the idea of something inside the dust boot to prevent rust, all
> my old manuals suggest something called "brake assembly paste" which I
> believe is pretty much silicone grease, but when I ask for it at the
> parts store I get blank looks... and the little tubes of dielectric are
> too expensive to use on brakes...

Syl-glide, available at any NAPA store.

Couple of bucks a tube.

On Fri, 21 Jan 2005 01:51:55 GMT, aarcuda69062
> wrote:

>In article >,
> Nate Nagel > wrote:
>
>> I like the idea of something inside the dust boot to prevent rust, all
>> my old manuals suggest something called "brake assembly paste" which I
>> believe is pretty much silicone grease, but when I ask for it at the
>> parts store I get blank looks... and the little tubes of dielectric are
>> too expensive to use on brakes...
>
>Syl-glide, available at any NAPA store.

Or CRC Synthetic Brake Caliper Grease


>
>Couple of bucks a tube.

On 21 Jan 2005 03:29:41 GMT, "TeGGer®" > wrote:

>Lawrence Glickman > wrote in
:
>
>> On Fri, 21 Jan 2005 01:51:55 GMT, aarcuda69062
>> > wrote:
>>
>>>In article >,
>>> Nate Nagel > wrote:
>>>
>>>> I like the idea of something inside the dust boot to prevent rust,
>>>> all my old manuals suggest something called "brake assembly paste"
>>>> which I believe is pretty much silicone grease, but when I ask for
>>>> it at the parts store I get blank looks... and the little tubes of
>>>> dielectric are too expensive to use on brakes...
>>>
>>>Syl-glide, available at any NAPA store.
>>
>> Or CRC Synthetic Brake Caliper Grease
>>
>
>
>That might work. Never seen it though.

It is unbelievably expensive unless you buy it in the 2.5 oz tube.
I bought the little packets that each contain enough *stuff* for one
caliper ;-\

It is a blend of a lot of things, including
molybdenum disulfide
graphite
Teflon
and a bunch of other junk
but it's advantage is it won't _drip_ or run-off parts at the enormous
temperatures brakes can sometimes reach.

I am guessing Anti Seize will also work, because that is supposed to
be good up to 1,600F ( think HO2S ), but, people say that will wash
off with road splash, so I stick with the CRC for the moment.

Lg