I have a 2012 dodge caravan bought new. After about 6000 miles the left rear brake began making a grinding noise, only when applied, every time the car sat more than a few hours, that goes away after about 2-3 miles. It began in winter and continues into the warm and dry days of spring now with 9000 miles total. Had it to dealer twice and inspection found no malfunction so they say its from rust build up because it goes away all the time and is nothing to worry about. It does not occur with the other wheels. My neice has the same van, in same geographic area and does not have this problem. Does this selective rust build up explanation make sense? Previously burned with bad brakes on a caravan, so am skeptical.
@MKMD It sounds to me like you’re still under new car warranty.
I believe that means the dealer should fix this, at no charge to you.
Make sure the calipers are properly engaging and releasing
Rust buildup within a few hours does NOT sound normal to me.
It sounds like they just aren’t very motivated to get a handle on it.
How loud is this grinding?
Brake components, like all parts of an automobile are manufactured to “nominal” specifications and when assembled the sum of deviations from perfect may all coincidentally be toward the same direction. I feel sure that I am not the only regular poster here who has turned brake rotors. And when turning rotors isn’t it common to find rotors that have a significant, raised ring at the outer circumference due to the pads being located somewhat inward from the ideal position. To eliminate the chatter I have chamferred the outer edge of brake rotors and pads being installed on rotors with the raised and often rusty ridge. That situation is a likely cause for the complaint and if so the dealership’s poor handling of the situation is inexcusable.
If you’re having “warm and dry days of spring”, then it isn’t rust buildup. On a rainy day (any day in Seattle) rust will rapidly form on the surface o brakes discs. I’ve had it form while I was in shopping with the ladyfriend at the local mall. But it comes off fairly rapidly. On a warm and dry day that will not happen.
I like Rod’s theory, but normally the problem he describes should not occur on a new car. And I agree that the dealer isn’t fulfilling his obligation. Few do.
@RodKnox turning rotors and chamfering pads seems a bit premature on a 9K car that’s still under new car warranty.
I’ve turned plenty of rotors, but I’ve never chamfered pads. Personally, I consider that to be modifying the brake pads. If I want chamfered brake pads, I’ll just buy some that were already chamfered by the manufacturer.
But that’s just my opinion.
Do you have rear disc brakes and those big open-spoked “Wagon Train” wheels that are so popular these days? If so, those open style wheel allow a lot of gunk to get to the brakes. I expect water/mud/dirt/rocks that have kicked up from the road are adversely affecting the brakes. It may be that all that is needed is the wheel taken off and the brake parts cleaned off with a hose end sprayer. If that doesn’t work, the brakes will need to be disassembled for a thorough inspection, cleaning, and lube.
OP shouldn’t be paying one red cent for any of this because the car is still under new car warranty and has 9K miles
For pity’s sake!
I was merely commenting on what seems a likely cause of the noise, @db4690. A customer’s threshold of annoyance to noise is sometimes phenomenal. And the deviations from ideal and perfect in the manufacturing of automobiles is immense. It’s a pity if there was no problem other than a rusty ridge on the outer edge of a brake rotor and the dealership’s shop blew off the owner when a few seconds with a Roloc pad would have eliminated the noise.