2009 Mercedes-Benz B-Class 2.0L Diesel · KW09 BXR

The 2009 Mercedes B-Class presents a mixed but broadly stable picture as of its most recent MOT on 30 September 2025 at 112,180 miles. That pass was preceded by a failure just one day earlier on 29 September 2025 at the same recorded mileage, where the tester flagged a leaking rear brake pipe connection, corroded rear brake pipes contaminated with grease, a corroded offside rear fuel pipe, a corroded rear anti-roll bar linkage, and a non-functioning nearside front dipped beam headlamp. The fact that all of those defects were rectified within 24 hours and the car passed the following day suggests a reactive repair rather than a sustained programme of preventative maintenance. The recurring corrosion on rear brake and fuel pipes, along with the anti-roll bar linkage, has appeared across multiple tests, indicating a slow but persistent deterioration pattern that the owner has been addressing only when it becomes a test failure point rather than resolving it systematically. The mileage profile is consistent and unremarkable for a vehicle of this age. Between 23 October 2023 at 107,238 miles and 5 October 2024 at 109,802 miles, the car covered roughly 2,564 miles over nearly a full year. From 5 October 2024 to 30 September 2025, it added a further 2,378 miles, arriving at 112,180 miles. That works out to approximately 2,400 miles per year in recent use, well below the stated annual average of around 6,599 miles across the vehicle's full 17-year life. The earlier years clearly saw heavier use, and the current low annual mileage may reflect lighter duty cycles or extended periods of inactivity, which itself can accelerate corrosion in brake lines, fuel pipes, and underbody components due to moisture sitting in the system without the drying effect of regular heat cycles. The 2023 failure on 3 October 2023 at 107,237 miles is the most mechanically significant entry in the record. A fractured offside front coil spring, an inoperative offside rear parking brake, parking brake efficiency below the legal threshold, and front brake imbalance across axle 1 all point to a vehicle that had been running with degraded suspension and braking components. The subsequent clean pass on 6 October 2023 confirms these were repaired, but a fractured coil spring on a 14-year-old car at that mileage suggests the suspension has endured considerable stress and the remaining original components, particularly the nearside front coil spring and both rear springs, deserve close inspection for cracks, sag, or corrosion jacking. The rear parking brake system should also be tested under load, as an inoperative cable or binding caliper can recur if the root cause was not fully addressed. A prospective buyer should focus the physical inspection on three areas. First, the rear brake pipework and fuel lines underneath the car, particularly where they cross the rear axle, should be examined for active corrosion, weeping, or previous patch repairs covered in grease or sealant. Second, the rear anti-roll bar linkage and D-bushes should be checked for play and advanced corrosion, as this has been flagged repeatedly and can cause knocks and unpredictable handling at low speeds. Third, the front suspension, especially the offside front coil spring that was previously broken, should be inspected for fracture lines, sag, or uneven ride height, and the front brake system should be road-tested for pulling or imbalance under firm braking. The nearside front headlamp dipped beam failure on the 2025 failure was likely a bulb or connector issue, but the headlamp aim and internal adjuster mechanism should be verified given the note about the internal adjuster being altered to recheck lights in 2024.