2010 Mercedes-Benz GL 4.0L Diesel · GJ10 GAJ

Corrosion of the brake lines and recurring fluid leaks represent the primary mechanical concerns for this vehicle, establishing a pattern of deteriorating consumables that requires immediate attention. While the Mercedes-Benz GL passed its most recent MOT on 27 October 2025, the inspection revealed a trend of persistent advisories regarding corroded front brake pipes on both sides and a non-excessive oil leak. The recent failure in October 2025 due to a compromised offside front upper suspension arm ball joint dust cover, combined with a severely deteriorated nearside front drive shaft CV boot, suggests that rubber components and metal lines are reaching the end of their serviceable life. The recorded mileage of 95,347 miles against a 2010 registration indicates a relatively low usage profile, averaging approximately 5,959 miles per year. While this lower annual accumulation generally implies less wear on the drivetrain and engine internals, it can often lead to the specific types of degradation seen here, such as the deterioration of rubber seals, CV boots, and dust covers due to age and environmental exposure rather than high mileage. The presence of corrosion on brake pipes and the deterioration of registration plates are common symptoms of a vehicle that may spend significant periods stationary or is subject to moisture retention in its underbody components. A prospective buyer must prioritize a thorough inspection of the braking system and the undercarriage. The advisory regarding corroded brake pipes covered in grease or other material is significant, as the coating can mask the true extent of the metal degradation. During a test drive, listen for any changes in braking feel or pressure, and pay close attention to any pedal judder or sponginess which could indicate air ingress or compromised hydraulic integrity. The nearside front brake pads were also noted as wearing thin, so a full assessment of the remaining pad thickness and disc condition is essential to avoid immediate replacement costs. Furthermore, the suspension and drivetrain components require close scrutiny. The recent failures regarding the upper suspension arm ball joint dust cover and the nearside front CV boot mean that the integrity of the steering and suspension geometry may be compromised. On the road, listen for rhythmic clicking sounds when turning the steering wheel at low speeds, which would indicate a failing CV joint, or any knocking and clunking noises when driving over uneven surfaces or speed bumps, which could signal worn suspension bushes or ball joints. Finally, the noted oil leak should be traced to its source to determine if it is a minor seal weep or a more substantial issue involving the engine or gearbox.