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

Reply to
BF
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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

Reply to
Daniel J. Stern

Reply to
maxpower

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

Reply to
BF

Nope.

Reply to
Daniel J. Stern

Reply to
Sam Steele

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.

Reply to
Joe

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

Reply to
BF

I had a 71 Dart Swinger with disk brakes. Rochester, NY salt routinely ruined the pistons. I prefer the cars of today.

Reply to
Art

REMOVE the NOCRAP in my address to reply.

Reply to
Len

Actually, stainless steel does not make a good rotor. Stainless has a very poor thermal conductivity, so it warps easily and cannot handle heat well.

The best rotors are made of wrought iron - but as virtually no-one makes real wrought iron any more, most are made of cast iron. Or cast steel. The material composition is pretty loosely defined,

That said, cracking of brake rotors, except on early ford Taurus and Sable cars, is pretty much un heard of. The major problem is sub-surface pitting - where the rotor develops a "glazed" surface, and the metal rusts away underneath. It has a lot to do with the composition of the pads, with iron metallic pads being a serious problem, particularly in the salt belt.

Reply to
nospam.clare.nce

Wrought iron is very rust resistant due to the inclusion of slag. It is very workable and ductile. It is "stringy" rather than chrystaline. Getting as close to wrought iron characteristics in rotors (and drums) makes for good brakes. Interesting point - a lot (OK, SOME ) of the "cheap import" rotors are closer to wrought iron than most of the american and high quality japanese stuff - and actually stand up BETTER when it comes to corrosion.

When you machine a good rotor the chips come off like consistent beads, not curls like from steel. Much like from cast.

Reply to
nospam.clare.nce

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.

Reply to
Sportster4Eva

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.

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

Reply to
KaWallski

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