2009 Mercedes C 2.5L Petrol · OU09 JYP

A seventeen-year-old Mercedes C-Class carrying a significant but localised brake-line corrosion issue dominates the mechanical history of this vehicle. The most recent test on 23 April 2026 was a pass, but the broader picture is more interesting than that single outcome suggests. In June 2023 the car failed its MOT outright on three Major defects, all relating to excessively corroded brake pipes on both nearside and offside front and rear circuits. This was accompanied by advisories noting pitted and scored brake discs at both axles. By July 2023 the vehicle had returned and passed, suggesting the brake lines were renewed and the discs either replaced or deemed acceptable. Since then the MOT record shows a stable pattern of passes alongside minor advisories, with the most recent flag relating to perishing on the offside rear tyre. The fact that brake pipe corrosion was severe enough to fail at 2023 but has not recurred is a positive indicator, though on a chassis of this age the underlying corrosion process rarely reverses and renewed lines are often only as durable as their underseal protection. The recorded mileage of 85,059 miles across seventeen years equates to an annual accumulation of roughly 5,000 miles, which sits well below the typical figure for a vehicle of this vintage. There are no obvious extended gaps in the MOT history, so the low mileage appears to reflect consistent light use rather than long periods of storage, although the annual figure is low enough that some component ageing from environmental exposure and infrequent use cannot be ruled out. Light usage of this kind generally preserves the engine internals and transmission but can bring its own concerns, including prolonged standing periods that may affect brake discs through surface corrosion, ageing of rubber components, and potential deterioration of underfloor and brake line protection through road salt and moisture exposure. The 2023 brake pipe failure aligns with this concern, as corrosion-driven defects are common on lightly driven cars that are nonetheless exposed to winter road conditions. For a prospective buyer, the brake pipe renewal in mid-2023 is the single most important item to verify. Any Mercedes C-Class of this generation is susceptible to corrosion along the brake lines, particularly where they run along the underbody and inside the wheel arches, and it is essential to confirm that the work was carried out to a satisfactory standard rather than a localised patch repair. On a test drive, listen for any knocking or binding from the brakes, particularly under light application, as the previous disc advisories suggested wear and pitting which, if the discs were not replaced, may now have progressed to the point of causing pedal judder or vibration under heavier braking. Inspect the underside thoroughly for any seepage around the renewed pipe runs and check the flexible hoses at each corner, as these rubber sections are typically the next corrosion-related failure point on this platform. The recurring tyre advisories on the offside rear, noted in 2025 for wearing close to the legal limit on its edge and in 2026 for cracking and damage, suggest a possible alignment issue or consistent kerbing or loading pattern on that corner. On inspection, examine the offside rear tyre shoulder closely and ask whether a tracking adjustment has been carried out, as uneven shoulder wear that recurs across replacements typically points to a geometry problem at the rear suspension rather than a simple consumable issue. Beyond this, the suspension and steering linkages on a C-Class of this age are known to wear, so on the test drive listen for clonks or thuds from the front over uneven surfaces, particularly over speed bumps, and pay attention to any vagueness or pulling in the steering. Given the mileage and age, the overall record is encouraging, but the brake line history demands physical verification and a careful inspection underneath before commitment.