Brake rotor rust opinions

04' Pacifica that's used mainly for trips and sits for long periods in
between. (and it's been very rainy for the last week or two)
This afternoon, I headed out in the car and at the end of the block applied
the brakes for the stop sign. Felt like all four rotors had warped half an
inch. Got back up to speed and applied the brakes a bit more aggressively a
couple of times. Still had bad vibrations.
Drove about 15 minutes at highway speed to my first stop. At speed, it felt
like tire(s) out of balance. Still had braking vibration. Checked the rotors
and they were badly rusted, as expected. By my next stop, another 15 minutes
at speed both the tire imbalance feeling and braking vibrations had gone.

So:
recommendations / opinions about how best to resolve this rust on rotors
issue?

Just drive normally?
Drive fast with quick stops until clear?
Drive slow with slow / low pressure stops until clear?
Reverse of either of the above two?
Doesn't matter, no harm is done either way?
Doesn't matter the same harm is done no matter what?
Other opinions?
Crackpot opinions?

Thanks,
BF

 

I doubt they were "badly" rusted. Surface rust appears on rotors almost
instantly in humid locations, and it can build up to coat the entire
surface of the rotor (except where the pad physically prevents water
access) quickly. This is why it felt like the rotors had warped; there was
a non-rusty patch on each of the four rotors. The proliferation of
open-frame alloy wheel designs that let you (and every raindrop) see the
pretty brakes has greatly aggravated the condition in recent times, though
it can occur with any kind of wheel.

It doesn't mean there's anything wrong with the car or the brakes. It does
mean you need to get in the habit of dragging your brakes the first few
hundred feet when the car's been sitting long enough for the condition to
occur. Don't drive especially slowly or quickly, just drag the brakes
until they clean up, then use them normally after that.

DS

 

I have no idea what Chrysler did to the Pacifica front and rear rotors, they
are really junk metal, they will pit really bad if sat for awhile. I had a
set already machined at work on my bench and threw them away because the
humidity in the shop ruined them, normally driving the vehicle will clean em
up but in some cases we have been replacing them. There are no TSBs for this
problem
Glenn beasley
Chrysler Tech
Do not replace the rotors for an appearance concern...Unless a customer is
experiencing brake noise or brake related roughness / vibration issues DO
NOT REPLACE a rotor(s) based on appearance only. The lining material
selected for this vehicle may pick up iron which becomes embedded in the
friction material resulting in scoring of the rotor surface. Rotor scoring
does not necessarily contribute to roughness, vibration, noise or any other
type of degraded brake performance.

 

Didn't mean to imply that I was worried about the rotors. But was wondering
if people had concerns about pads or other components and how they would
best to try protect them.
The rotors are just great chunks of cast mild steel, so it would take
decades for corrosion to do any real damage to them. But I don't know if
there are other considerations to worry about.
BF

 

Nope.

 

Some of the shops I deal with use a zinc rich weld through primer that body
shops use to spray into the vented slots of the rotors and thus provide a
sacrificial anode that will prevent surface rust.

 

You may not need this info, but you mentioned tire balance. You should
expect your tires to thump also if you don't drive for a long time. It might
take several miles to take the flat spot out of them, but eventually they
should get round again.

 

Thanks Joe,
Could be part of it but I suspect most was the rust intermittently hitting
the calipers.
BF

 

That's a pretty cool idea..
Going to have to remember that one when the wheels come off in the
spring, to put on the summer tires.

 

There are 2 (two) things to consider in the makeup of the brake rotors and
drum's material. Beyond basic metalurgy and wear, the chemical makeup of the
material and the location of use create the circumstance. However the metal
fails to remain inert for more than the two reasons as I implied earlier.
Chemical and Biological reasons. Look it up. The Titanic is rotting away
faster than so-called experts (or had previously) explained. Ask any
MicroBiologist. Rust can happen due to many reasons but there is a third
that is often overlooked. Iron eating bacteria. It exists in more situations
than discussed.

Many times I wondered why a so-called dry block rotted away after only a few
months while only a few feet away another block looked pristeen.

http://www.google.com/search?hl=en&q=iron+eating+bacteria&meta=

So don't discount the obvious but don't dismiss the remote until you know
all the reasons...