Giulietta - Mystery Front brake issue

[cc]

Hi
While the partner and I had been driving in stop start traffic in the Giulietta we noticed a light coloured smoke from the front left  of the car.. A smell of brakes,... (not oily) and pulled over to investigate.
All fluids temperatures and belts looked fine. No untoward noises.
The issue hasn't re appeared. The rotor looked ok. Haven't checked the pads.
Any thoughts on what it may be?
The lower front of the car had being grounded/bottomed out at the bottom of a steep driveway in the previous month.
cheers CC

[bazzbazz]

Check for oil leaks around the air pump that's on the top passenger side of engine. If the gasket develops a leak it drips on hot piping under it and burns - hence the white smoke.