2001 Jeep Cherokee Front Brake Rotors

jim wrote:
>
> aarcuda69062 wrote:
>> In article >,
>> jim <"sjedgingN0Sp"@m@mwt,net> wrote:
>>
>>> aarcuda69062 wrote:
>>>> In article >,
>>>> TomO > wrote:
>>>>
>>>>> Hi group,
>>>>>
>>>>> Tonight I was foiled by either a pair of very stuck rotors or by some
>>>>> means of holding them to the hub that was not readily apparent to me.
>>>>>
>>>>> This is a 2001 Jeep Cherokee. The rotors look as if they should just pull
>>>>> off the hubs once the caliper is removed. But try as I may, I could not
>>>>> get them loose with a three-jaw puller, nor could I see any means of
>>>>> holding them in place.
>>>>>
>>>>> Is there something I missed, or are they just severely rusted in place?
>>>>>
>>>>> Thanks!
>>>> Severely rusted in place.
>>>> Cheap brake pads with high iron content will do that.
>>> I thought it was pads made for racing applications that had high iron
>>> content.
>> The rock bottom cheapy pads are also high iron content.
>
> The spindle, hub, rotors and calipers usually have higher iron content.
> Do you think the iron in the pads is the straw that breaks the camel's
> back.
>
> Metallic pads can be cheap or expensive. Is it just the cheap one's
> that cause the problem?
>
>>> But anyway don't you suppose the iron in the rotor and hub
>>> plays some part in why the two rust together?
>
>
>> Nope. The problem is more or less non-existent if ceramic pads are used.
>
> And I suppose if ceramic pads are used and the rotors still stick to
> the hub, (which they certainly do) that is just an indication that
> somewhere out there there must be a set of higher priced pads?
>
>
> How much time lapses between removal of the rotors definitely has
> something to do with it. And that could be related to the type of pads
> used.
> Not driving thru slush puddles with high salt content also helps
> a lot.
> Applying a little anti-sieze or grease around the center hole will
> definitely help avoid the problem on the next removal.

A lot of factory rotors fit tight on the OD of the hub. I don't know if
this is one. If so, it might be easiest to cut it off.

In article >,
jim <"sjedgingN0Sp"@m@mwt,net> wrote:


> > The rock bottom cheapy pads are also high iron content.
>
> The spindle, hub, rotors and calipers usually have higher iron content.
> Do you think the iron in the pads is the straw that breaks the camel's
> back.

I think it is the iron sloughing off the pads as they wear that causes
the problem.

>
> The rock bottom cheapy pads are also high iron content.


Iron is the metal in "semi-metallic" pads and has been for years, long
before ceramic pads were on the market. I'm sure that the iron dust from
semi-met pads can contribute a little to sticking the rotors in place,
but then its just DUST by the time it gets near the hub. The iron in
the rotor and hub will rust together just fine without added iron dust
from the pads, given the right (corrosive) conditions.

Steve wrote:
>
> >
> > The rock bottom cheapy pads are also high iron content.
>
> Iron is the metal in "semi-metallic" pads and has been for years, long
> before ceramic pads were on the market. I'm sure that the iron dust from
> semi-met pads can contribute a little to sticking the rotors in place,
> but then its just DUST by the time it gets near the hub. The iron in
> the rotor and hub will rust together just fine without added iron dust
> from the pads, given the right (corrosive) conditions.


It doesn't seem like it would be that easy for the dust to arrive where
it needs to be. It is not as if dust will flow thru the cracks between
closely matched mating surfaces like water will.

I thought the theory behind this idea was going to be that metallic
brake pads are electrically conductive while ceramic are not (don't know
if that is even really true, but it sounds good). That would mean there
was a closed ground loop that the hub to rotor interface is part of and
that leads to the corrosion.

-Jim

Steve wrote:
>
>>
>> The rock bottom cheapy pads are also high iron content.
>
>
> Iron is the metal in "semi-metallic" pads and has been for years, long
> before ceramic pads were on the market. I'm sure that the iron dust from
> semi-met pads can contribute a little to sticking the rotors in place,
> but then its just DUST by the time it gets near the hub. The iron in
> the rotor and hub will rust together just fine without added iron dust
> from the pads, given the right (corrosive) conditions.

VERY common for rotors to rust on. Take a look at the design and it
becomes REAL obvious. The hub bore is a very tight fit on a good rotor.
However none of the wheels out there fit that way. There is always a
small space behind the wheel where it fits to the hub and this lets
water/dirt/brake dust all collect in there. Toss in some damp weather OR
salt on the roads and you get a good rust ridge around the hub that
locks the rotor on.

Easy way to stop it is to clean everything very well. Install the new
rotor and use a THIN bead of silicone sealer around the hub center
before you install the wheels. The silicone will keep water/dirt out of
the interface and allow the rotor to be removed easier.
--
Steve W.

In article >,
Steve > wrote:

> >
> > The rock bottom cheapy pads are also high iron content.
>
>
> Iron is the metal in "semi-metallic" pads and has been for years,

It's one of them and varies depending on the specific brake pad.
You may also find copper or aluminum and god knows what else.

> long before ceramic pads were on the market. I'm sure that the iron dust from
> semi-met pads can contribute a little to sticking the rotors in place,
> but then its just DUST by the time it gets near the hub.

It's dust in Texas and other parts of the arid south, move out of that
region and add some water and you've got an iron based cement that sets
the stage for posts like the OPs.

> The iron in
> the rotor and hub will rust together just fine without added iron dust
> from the pads, given the right (corrosive) conditions.

And they rust together worse when swathed in iron powder + moisture.

In article >,
jim <"sjedgingN0Sp"@m@mwt,net> wrote:

> Steve wrote:
> >
> > >
> > > The rock bottom cheapy pads are also high iron content.
> >
> > Iron is the metal in "semi-metallic" pads and has been for years, long
> > before ceramic pads were on the market. I'm sure that the iron dust from
> > semi-met pads can contribute a little to sticking the rotors in place,
> > but then its just DUST by the time it gets near the hub. The iron in
> > the rotor and hub will rust together just fine without added iron dust
> > from the pads, given the right (corrosive) conditions.
>
>
> It doesn't seem like it would be that easy for the dust to arrive where
> it needs to be. It is not as if dust will flow thru the cracks between
> closely matched mating surfaces like water will.

What do you think it will do when it gets wet? Or doesn't it ever rain
or snow where you are?

> I thought the theory behind this idea was going to be that metallic
> brake pads are electrically conductive while ceramic are not (don't know
> if that is even really true, but it sounds good). That would mean there
> was a closed ground loop that the hub to rotor interface is part of and
> that leads to the corrosion.

Actually, it doesn't even sound good.

"aarcuda69062" > wrote in message
...
> In article >,
> jim <"sjedgingN0Sp"@m@mwt,net> wrote:

>> I thought the theory behind this idea was going to be that metallic
>> brake pads are electrically conductive while ceramic are not (don't know
>> if that is even really true, but it sounds good). That would mean there
>> was a closed ground loop that the hub to rotor interface is part of and
>> that leads to the corrosion.
>
> Actually, it doesn't even sound good.

You're right, Aarcuda...it doesn't sound good at all.

hls wrote:
>
> "aarcuda69062" > wrote in message
> ...
> > In article >,
> > jim <"sjedgingN0Sp"@m@mwt,net> wrote:
>
> >> I thought the theory behind this idea was going to be that metallic
> >> brake pads are electrically conductive while ceramic are not (don't know
> >> if that is even really true, but it sounds good). That would mean there
> >> was a closed ground loop that the hub to rotor interface is part of and
> >> that leads to the corrosion.
> >
> > Actually, it doesn't even sound good.
>
> You're right, Aarcuda...it doesn't sound good at all.

So obviously you don't have the slightest clue whether or not metallic
pads are more electrically conductive than ceramic ones.

-jim

On Fri, 31 Jul 2009 12:04:09 -0500, aarcuda69062 wrote:

> In article >,
> jim <"sjedgingN0Sp"@m@mwt,net> wrote:
>
>> hls wrote:
>> >
>> > "aarcuda69062" > wrote in message
>> > ...
>> > > In article >, jim
>> > > <"sjedgingN0Sp"@m@mwt,net> wrote:
>> >
>> > >> I thought the theory behind this idea was going to be that
>> > >> metallic brake pads are electrically conductive while ceramic are
>> > >> not (don't know if that is even really true, but it sounds good).
>> > >> That would mean there was a closed ground loop that the hub to
>> > >> rotor interface is part of and that leads to the corrosion.
>> > >
>> > > Actually, it doesn't even sound good.
>> >
>> > You're right, Aarcuda...it doesn't sound good at all.
>>
>> So obviously you don't have the slightest clue whether or not
metallic
>> pads are more electrically conductive than ceramic ones.
>>
>> -jim
>
> Are the seats cloth, vinyl or leather?

Vinyl.
(You just gotta love usenet)