2017 Mercedes-Benz B-Class 1.6L Petrol · AF67 VLL

The most recent MOT test, conducted on 2025-09-12, resulted in a passing grade, though it did reveal a persistent and critical issue with the offside front constant velocity (CV) joint boot, classified as severely deteriorated under DVSA standard 6.1.7(g)(i). This defect is a minor failure point, indicating that the boot has failed to adequately seal the CV joint, allowing contaminants to enter and accelerate wear within the joint itself. While the vehicle passed, this condition must be addressed promptly, as CV joint failure can lead to catastrophic drivetrain failure, particularly under acceleration or when cornering, with symptoms such as a loud, rhythmic clunking noise emanating from the front left wheel area, especially when the vehicle is driven at speed or under load. The advisory regarding thin rear brake pads—classified under 1.1.13(a)(ii)—suggests that the friction material is approaching the legal minimum thickness, which could compromise stopping performance if not replaced soon. This is a recurring advisory, indicating a pattern of wear that may warrant closer monitoring, particularly if the vehicle is subjected to frequent braking or heavy loads. The recorded mileage of 43,494 miles for a vehicle aged nine years is notably low, translating to an average annual usage rate of approximately 4,833 miles, which is significantly below the industry average for a vehicle of this age. Such low mileage often reflects periods of prolonged stationary use, particularly if the vehicle was parked in a climate-controlled environment or used primarily for short commutes. However, this usage profile does not necessarily mitigate the risk of wear-related failures, especially in components that degrade over time rather than through mileage, such as the CV joint boot, brake pads, and suspension elements. The absence of higher mileage accumulation over the past few years could mask underlying issues, like suspension bush wear or internal engine/transmission wear, which might only surface when the vehicle is driven more extensively. Additionally, the vehicle’s age and low mileage raise concerns about potential issues stemming from prolonged standing, such as brake disc corrosion, caliper binding, or fluid degradation due to stagnation. For a prospective buyer, the most pressing immediate concern is the severely deteriorated CV joint boot, which should be replaced without delay to prevent joint failure and costly repairs. During a test drive, listen for the characteristic clunking noise when accelerating or turning, particularly on the offside front wheel, and check for any uneven tire wear or vibration that could indicate misalignment or drivetrain issues. The thin rear brake pads should be addressed within the next few months, with the friction material replaced to ensure safe stopping performance. Beyond these defects, given the vehicle’s age and low mileage, focus on inspecting the tires for signs of sidewall cracking or perishing, which can occur even with minimal use if the rubber has been exposed to prolonged environmental conditions. Check the 12-volt battery for signs of corrosion around terminals and ensure it holds a charge, as standing vehicles can lead to battery drain or sulfation. Inspect the brake discs for corrosion or binding, particularly on the rear, where the advisory suggests wear is approaching critical levels. Verify that all fluids—coolant, brake fluid, differential and transmission fluids—are topped up and free from contamination, as fluid degradation can accelerate wear in these systems. Finally, examine the suspension for signs of excessive play or unusual noises, such as clunks or rattles, which could indicate worn suspension bushes or broken coil springs, and ensure the exhaust system is free from leaks or structural damage, as emissions performance and structural integrity are critical for both roadworthiness and safety.