Summary
The Volvo S40 has 11 recalls spanning the 2000–2011 model years, with the most serious being a brake master cylinder defect on 2007 vehicles where an internal seal wears prematurely, allowing brake fluid to leak internally and forcing the driver to press much harder than normal to slow the car.
The 2011 model year has a structural recall: a crack in a passenger-side engine compartment support member can reduce how well the front structure holds up in a crash. On 2009–2011 vehicles with power front passenger seats, a faulty detection system in the seat rail can allow the seat to travel forward past its intended limit, placing the occupant closer to the dashboard than designed and raising the risk of injury in a crash. Going back to 2008 models, the power steering return hose can rupture suddenly, drain the steering fluid, and leave the driver with full manual steering effort at any speed. There is also a 2004 brake issue where a cracked non-return valve creates a vacuum leak, requiring extra pedal force to stop, and a 2004 fuel pump module that can corrode from water intrusion and cause the engine to stall or fail to run.
On the fuel side, 2005 vehicles with T5 turbo engines have a plastic fuel line routed near the turbo and exhaust that can soften and leak, creating a fire risk from fuel near hot components. A separate 2005 recall, covering vehicles registered in northern salt-belt states, involves fuel pump corrosion that can cause stalling or a no-start condition. The 2003 model year has a fuel rail with inadequate welds that can leak fuel and ignite if an ignition source is nearby. The 2000 model year has a brake vacuum pump that can take on water and fail, eliminating the power assist and requiring significantly more pedal effort to stop. The 2001 model year has a climate control diode that can fail and disable the heater fan and defroster.