One problem related to brake drum wheel cylinder has been reported for the 2002 Volvo S40. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Volvo S40 based on all problems reported for the 2002 S40.
I was driving on a main road and my brakes failed. It was determined that a brake line corroded through. It appears that the vehicle has a single master brake cylinder. I asked a Volvo dealership about this, and they confirmed to me that the master brake cylinder is a single one. It is my understanding that in the 80's, all vehicles sold in the united states were to have a dual master brake cylinder.