Rusty rotors after car sat for a few months

[mclasser]

Hey guys, my Pilot & Accord sat parked outside for a few months while I was away for work. I took the Pilot for a drive after I returned and it's making a *thump thump thump* noise when braking. I thought it was just surface rust on the rotors that would clear off but I drove nearly 30 miles in various braking situations and the noise is still there. In contrast, the brakes in my Accord are quiet and smooth.

Here's a pic of one of the rotors. The rest look just like this, almost pitted(?).... Do I have to do some aggressive stops to scrub the build up off?? The noise is pretty annoying.

 

[Chris142]

Dunno. I have never seen anything like that.

 

[Chris Meutsch]

That ain't wearing off. I think replace.

 

[Jetronic]

The rust is harder wearing than the clean metal, it won't ever wear off when it's progressed like that.

 

[Cujet]

I'm not sure that's a disaster. Hard to tell how deep the rust pits are. I don't think there is any downside to performing a series of hard stops from speed.

When I do this, I generally go out of town on a remote road, and perform 3 brake pad bedding stops, often down to 5mph, then get going to cruising speed again and let the brake parts cool down at speed. Then perform 3 more stops from speed. Never completely stopping.

The one thing I try to avoid is stopping completely with the hot brake pads resting on a specific rotor location.

 

[slacktide_bitog]

Get new rotors and drive the car at least once a week from now on

You could always do some more hard stops like others are suggesting

 

[BlueOvalFitter]

I have noticed surface rust on my rotors after sitting for a few days. The first time, or two, using the brakes, it's gone.

 

[eljefino]

Yeah if 30 miles didn't clean them off they're done. Turn or replace.

 

[Dave9]

Could be the rotors but I would also wonder about the slide rails and pins, would take the rotor off and see if those need cleaned and lubed.

 

[ka9mnx]

I wouldn't replace them. Keep driving, it will get better.

 

[Shel_B]

I'd take the car to a competent and well-regarded brake shop and see if the rotors can be turned. If not, replace them. In either case, have the rest of the brake system checked and the necessary parts replaced.

 

[atikovi]

it's making a *thump thump thump* noise when braking.

Where the pads were resting, the rotor didn't rust. It's thumping as the rotor turns from the rusted to unrusted area when braking. Figure on 50 to 100 miles of driving per month of sitting for that noise to go away. No you don't need new rotors, turn rotors, or take it in to a shop. Brand new cars can sit at the dock for 3-6 months waiting to get shipped and they don't do anything about it.

 

[Danno]

I see that on cars on our lot that have sat for a while.

Replace them imo.

Exact same situation and rotors looked the same this week on a Toy CH-R. Our mechanic had to replace them.

 

[VolvoZ]

Assuming you have an angle grinder with either a sanding pad or grinding wheel, this can be fixed by lightly grinding or sanding the entire surface of the disk being careful to evenly abrade the surface. For DIY, this is the cheapest and easiest method. Also, it is very likely that only the exposed outer surface is affected by rust, so you should not have to abrade the inner surface. I have done this several times before for moderately rusted disks with success, including just two weeks ago on a friend’s Volvo S80 that was making the “thumping” noise due to rust from sitting. Turning the disk would be the next cheapest option, usually.

Regular usage may or may not eventually take care of the pitted disk area. I think it really depends on how abrasive your brake pads’ friction materials are.

 

[JavierH19]

it's honestly not a big deal. what i do is lightly ride on the brakes until a barely feel resistance for a half minute. last time i went on a cruise was for two weeks and after parking my suv near the beach i noticed the rotors were nice and rusted out as hell with a bit of pitting. No big deal i resurfaced them just by breaking and the pitting eventually went away after a while. They once were also warped and would brake inconsistently but i eventually resurfaced them after a year. Truth is not much will happen. Not like they're gonna disintegrate and you'll go crashing. At worst you'll wear your pads faster like me but if you have enough meat on both the pads and rotors it'll be okay and you wont have to replace the rotors at least for a couple more years. I say to just drive it like that. The thumping is probably just the area under the pad that didn't get rust and is acting like a hill when you brake. No big deal either.

 

[joekingcorvette]

My son and I drove 5 different used Jeep Cherokee Trailhawks. They were all sitting on the lot for a few weeks and hadn't been driven. Every one of them had brakes that would vibrate and shudder on our test drives. The salesman said it was just from sitting with being driven much. He bought the one with 2,000 actual miles and the brakes were a little shaky for the first 100 miles and they miraculously were perfect after that. Your brakes will be just fine and I am sure you figured it out by now. Its bare metal and they rust up quickly if they get wet the rotors turn rusty. Yours look a little more pitted than normal but I would just drive it and it should be just fine.

 

[Jetronic]

Where the pads were resting, the rotor didn't rust. It's thumping as the rotor turns from the rusted to unrusted area when braking. Figure on 50 to 100 miles of driving per month of sitting for that noise to go away. No you don't need new rotors, turn rotors, or take it in to a shop. Brand new cars can sit at the dock for 3-6 months waiting to get shipped and they don't do anything about it.

the discs never look like that though, i'm thinking they had salt on them when it was parked

 

[Hall]

Where the pads were resting, the rotor didn't rust. It's thumping as the rotor turns from the rusted to unrusted area when braking. Figure on 50 to 100 miles of driving per month of sitting for that noise to go away. No you don't need new rotors, turn rotors, or take it in to a shop.

Agree with this and if it's not the case, there's no harm in "trying". Brakes will work just fine, just be annoying for a while. The OP should act like these are new pads and rotors and do the more aggressive burnishing technique. Here's one:

https://www.brakepartsinc.com/dam/jcr:3dd70239-f732-4891-b074-749acb4c6907/Tech%20Tips%20Police%20Burnishing.pdf

 

[GMBoy]

I've seen much worse as in the entire rotor is brown with rust. Drove them riding the brake pedal slightly for about a 1/4 mile then did several slow/medium stops where the pads are touching the rotors for a good while to scrub them. Then do a few hard stops and then all is well again.