Honda Repair/2010 Honda Civic EX-L
Hello: I had a strange experience with the subject car yesterday.I had it washed on the way home from work on Friday,and on Sunday,after it sat two days in the garage,I went to pick up a pizza. When I put it in drive (I always back into the garage),I heard and felt a distinct "clunk" from the back end,and the car lurched forward.After that,it drove normally.This episode reminded me of what happens in winter (when I assume wash water freezes the brake pads to the drums) if I start to drive after having had it washed the previous day,but what would cause it to happen in summer? The parking brake was not on.
The most likely cause of this problem is simply rust! After you parked the car it's likely that there was still some moisture on the rotors. While sitting this small amount of moisture can cause the rotors to develop a thin layer of rust. When you put your car in drive, the clunk you heard was probably the brake pads breaking free of the rust.
It's normally nothing to worry about as a few normal stops and the rotors will be free of the rust.
Even if you leave your car sitting in your driveway for a few days the rotors would rust a little just from the dew and moisture in the air.
I hope this helps!