2009 Mercedes-Benz CLK 2.1L Diesel · AF09 OUC

The latest MOT test in December 2025 resulted in a pass, though it carried forward advisories and minor defects from a failed test the previous day, notably a dangerous offside rear tyre cut that required immediate replacement. The broader history shows a gradual deterioration in the brake pipe condition, with corrosion advisories first appearing in 2021 and expanding to multiple lines by 2024, indicating a worsening trend that demands close attention. While the vehicle has passed its last test, the recurring brake pipe advisories and the recent tyre failure suggest that underlying maintenance has been reactive rather than preventative, and the overall condition appears to be slowly declining. At 79,575 miles over 17 years, the annual average of around 4,680 miles is low for a vehicle of this age, which raises concerns about prolonged periods of inactivity. Extended standing can lead to its own set of issues, such as seized or binding brake calipers, corroded brake discs, and degraded seals or gaskets from lack of use. The mileage pattern does not indicate excessive wear from high usage, but the age-related deterioration of components remains a significant factor, particularly for rubber, plastic, and fluid-based systems that degrade over time regardless of mileage. The recurring brake pipe corrosion advisories are a critical area for inspection, as these lines are essential for safe braking and can fail without warning if the corrosion penetrates deeply. On a test drive, listen for a soft or spongy brake pedal, which may indicate air in the system or fluid loss, and inspect for dampness or staining around the pipes and connections. The recent tyre failure also highlights the need to examine all tyres for age-related cracking, uneven wear, or embedded debris, as low-mileage vehicles often suffer from perished rubber due to age rather than wear. Additionally, check the condition of the brake discs for surface corrosion or pitting, which can cause juddering under braking, and ensure the calipers are not binding, as this is common in vehicles that have stood for long periods. Given the vehicle’s age and low mileage, a thorough inspection of time-sensitive components is essential. Verify the health of the 12V battery, as older batteries can fail without warning, and assess the condition of all fluid systems, including brake, power steering, and coolant, which degrade over time. Inspect suspension bushes, droplinks, and coil springs for wear or corrosion, as these can deteriorate even with minimal use. Finally, review the service history to confirm that time-based maintenance, such as timing belt or chain replacement, has been carried out, as these are critical to the engine’s longevity and are often overlooked in low-mileage, older vehicles.