How true isit that a cars brakes will rust and then pit if it is not driven more than 2times a week?


#1

Specifically 2003 Toyota Highlander. We keep hearing this same refrain about a car that we have that at times (5 months out of the year) is driven daily and the rest of the time twice weekly.


#2

If you live by the ocean, maybe. I wouldn’t worry about it otherwise.


#3

Well? Dealers have vehicles sitting on their lots for months at a time, and people store vehicles for months at a time. And there’s usually not a problem with pitting of the rotors from rust on most vehicles.

However, some vehicles came from the factory with such cheap rotors that they would rust and pit even if you drove the vehicle everyday.

Fortunately, Your vehicle isn’t one of them.

Tester


#4

You’ve got nothing to worry about


#5

Probably depends on climate and the particular rotor and pad materials. Rear drums on my old car squeak almost every time I drive it out (daily) until I use the brakes a couple of times. Then they’re quiet.


#6

This is something a Sherlock-Holmes scientist would gleefully approach with a deer-slayer hat and a big microscope I suppose. But since we have no such scientists with hats and microscopes employed here, my guess, there might be a little surface rust forming between drives, but if you drive twice weekly that would buff it off before much pitting action could happen.


#7

I had a Passat that frequently went for 3-4 days undriven, and live in New England. When I had the front brakes checked at one point, the mechanic said the rotors had rust holes in them, in places eaten all the way through.

But I took his word for it, never looked at them myself.


#8

If you drive into salt water with drum brakes and then park for a few weeks the results can be significant. An M38A1 Jeep will not budge when that occurs. But I have never seen rust from long periods of being parked cause a problem beyond the dragging sound that disappears within a mile when driven again.


#9

Add on from my above post: my theory is this: Some rust can accumulate if there is salt and moisture present and the car is not driven for a few days. If a rust pit gets deep enough in that period, when you do drive the car and wear off the surface rust, there still remains the rust in the deep pit, which can continue to rust, as it is below the surface and not subject to being worn off by the pads. Eventually the pit gets deep enough and wide enough to reduce your braking and a safety issue.

Just a theory.


#10

Surface rust will occur on all rotors and drums just sitting in a parking lot on a rainy day, however it disappears with the first brake use and is harmless.

Tester has posted some excellent points.

I have seen serious rotor rot on a car that was parked under pine trees on wetland (a wooded surface that stays wet all year around) for six months or so, but that’s a really extreme exposure. The rotors were so rotted that the cooling vanes were plugged with rust, some of the vanes actually rotting away, and the disc portions were distorted and splayed out. Based on this experience, I would suggest that if you park under pine trees in a wet-surfaced area you should try to use the car regularly.


#11

Yes, the brake rotors will rust always, everytime, all the time. No matter how you drive it. They are bare cast iron exposed to moisture in the air, water splash, snow and salt. As many here have correctly pointed out, it won’t really cause much harm.

That said, cars that don’t get used much may rust out their rotors or drums before the brake pads or shoes wear away. The edges rust away reducing the contact area of the pads. I have had to replace rusty rotors many times before the pads wore out on my lightly used cars. You’ll know it because the brakes likely will be a bit noisey, pulsate or your mechanic will point it out while rotating your tires. (you DO rotate, right?)


#12

Well, you don’t need to live next to the ocean, just where they use salt on the roads in winter. I have a Camry that sits most of the time. Last year, I took it in for inspection and the guy comes out and asks what I did to the car- it looks like it sat at the bottom of the ocean!

Sure enough, the calipers, rotors and everything else was completely rusted. The backing plates are essentially gone, completely rotted away. I had to replace almost everything.

Not the first time I’ve seen this. Living in the midwest, my Dad rarely drove his car and all of them rotted out prematurely from the bottom up.

Exposure to salt/slush and sitting do not make a good combination…

Dealer cars sit, true. Essentially in one spot. They only get moved to plow the snow off the lot or to be sold. They aren’t driving them down the road once a week for an entire winter are they?


#13

True & False, Both

The comments above agree that it’s true in some cases, salt exposure, for instance, and false in others, such as cars on dealer lots, being stored, etcetera.

I have 7 cars and now only 3 drivers. They can’t all be used at the same time. So, some sit for periods of time, up to six or seven months, without a problem of brake rotor rust (outside in a fairly humid climate).

On the other hand, (I’ll blame my wife here) my wife drove her car during the winter road salt season a few years ago and then parked it for a couple of weeks and drove something else. The brakes turned to junk!

Also, as noted above, all brake rotors rust all the time. However, usually the small amount of rust is cleaned off when the car is driven and brakes are applied.

There is a difference in rotor quality, too. Some cheap rotors come with pitting in them when purchased. I have had my best luck with OE rotors that were on the vehicle from the factory.

CSA


#14

A car will eventually wear out or rust and rot out or a combination of the two.


#15

I have a 1979 with 71k and original brakes.
So I guess it’s all relative to conditions.


#16
I have a 1979 with 71k and original brakes.

Rotors are made a lot thinner now. Some you can’t even mill.


#17

Here in the heart of the rust belt, if you don.t wear out the brakes in three years, they will surely rot out. Unless you don’t drive them in the salt. There are people around here that put their “good” car away at the end of October and bring them back out in May. They buy a rusty heap for the winter.


#18

So in the rust belt driving it more often wouldn’t help, right? Just get more salt on them?


#19

“So in the rust belt driving it more often wouldn’t help, right? Just get more salt on them?”

It does help me to drive frequently in the salt belt. Even though it can subject the brakes to more salt, it’s the sitting and rusting in place that’s bad news, especially where the pads are in close proximity to the rotors. The trapped salt water in there rally does a number on the rotors. The caliper slides on certain makes seize up and pads stick, too.

In the winter, if I’m going to let a vehicle sit for a while, I try and find a rare day that the roads dry off. Them I drive the car, heat the brakes up, and then park. Even on dry roads the tires blow up clouds of salt dust. It’s a thing of beauty. I can’t get enough of it.

CSA


#20

LOL, salt clouds a thing of beauty? I never thought of them that way. Well, whether they are or not, they’ll be here soon!! :smile: