I noticed a pulsating feeling when I applied the brakes in my 2001 Ford Focus. I figure that it might be warped rotors, but after driving the car for a while, it seems to have dissipated. The car was sitting around for a few weeks. I read that it could just be rust buildup, but I feel that would require more than a few weeks of sitting around. Is there any way to check for myself, short of taking off the rotor? Thanks.
Actually rotors can acquire a coating of rust in only a few days of not being driven.
You should be able to see the rotors–to some extent–through the cooling slots in the wheels.
If you don’t see any rust at this point, then you don’t have any.
One rainy night and can I see the beginnings of rust on close inspection.
A few weeks could easily build up enough grunge to feel when driving.
In car sales they call it “lot rot”.
One area of the rotor is more exposed to the weather than the other,
so the rust can be uneven and give symptoms of warping.
And I’m sure you’ve driven it off. Drive on.
I’ve seen my rotors develop a coat of rust on a rainy day just while I was shopping at the mall. Rotors develop surface rust very quickly under the right weather conditions.