2011 Mercedes-Benz B-Class 1.7L Petrol · FD11 TFF

A clear and escalating brake and steering-related defect pattern dominates the MOT history of this 2011 Mercedes-Benz B-Class, with the most recent test on 14 June 2025 producing both a pass and a fail on the same date. The failure at that visit was driven by two electronic warning lamp issues, namely an inoperative or malfunctioning engine management indicator lamp (MIL) and a supplementary restraint system (SRS) warning lamp indicating a fault, both classed as dangerous. Prior to this, the 2024 test sequence shows a significant mechanical deterioration, with brake pipes excessively corroded on both the front-to-rear run and the nearside rear, items which had previously only been noted as an advisory on the front-to-rear pipe in 2023 when it was recorded as corroded but covered in grease. This brake pipe progression from advisory in 2023 to major failure in 2024 is the standout structural concern in the record. The 2025 advisories then layer in worn front brake discs, thinning front brake pads, a deteriorated nearside front outer CV joint boot, an offside front tyre worn on the inner edge close to the legal limit, and slightly discoloured rear direction indicators, while the 2024 pass also flagged slight free play in the offside inner steering rack at the wheel joint. Against its fifteen-year build date, the recorded mileage of 81,500 miles equates to roughly 5,433 miles annually, which is notably low for the vehicle's age and indicates either periods of light use or extended standing time between journeys. The annual testing rhythm is well-maintained with no missed tests since 2020, and mileage accumulation appears broadly consistent year on year rather than showing any sudden jumps that would suggest heavy motorway use or towing. However, low annual mileage on a vehicle of this age frequently correlates with corrosion-related issues rather than wear-related ones, as components such as underbody brake lines, exhaust hangers, and suspension subframes are exposed to road salts and moisture during short trips without sufficient sustained running to dry them out. The presence of under trays noted in the 2024 advisories may have been masking developing corrosion, and the brake pipe defects recorded support the likelihood of an underbody corrosion trajectory rather than a wear-driven one. For a prospective buyer, the priority inspection areas should be the underbody brake lines along their full front-to-rear length, including the nearside rear section previously flagged as excessively corroded, checking for any pitting, flaking, or weeping at joints. The CV joint boot deterioration noted as a minor on the 2025 test should be inspected for fresh grease loss around the boot lips and any clicking or vibration through tight turns, which would indicate advanced wear. The offside inner steering rack free play recorded in 2024 warrants a road test focusing on steering precision, particularly any knocking or sloppiness around central lock and any uneven tyre wear that might confirm a worn inner tie bar end. On a test drive, listen for brake pedal sponginess or excessive travel which could indicate further pipe corrosion or air ingress, and feel for any pulling to one side under braking which might suggest a binding caliper following pad or disc replacement. Given the dual electronic warning lamp failures on the most recent test, a diagnostic scan of both the engine management and SRS systems is essential before purchase, as unresolved MIL and airbag faults can indicate underlying sensor, wiring, or control module issues that may prove costly to remedy on a fifteen-year-old platform.