If you drive a recent-model Mercedes-Benz S-Class, Maybach, or AMG sedan, take note: Mercedes-Benz USA (MBUSA) has broadened an earlier safety campaign regarding potential front brake hose failure. Filed under NHTSA Campaign Number 26V-638, this action covers 30,064 vehicles across multiple high-end model lines.
What Is the Defect?
According to Mercedes-Benz AG (MBAG), the front axle brake hoses on affected vehicles may suffer from accumulated material fatigue. Over time, increased thermal and mechanical stresses sustained during regular driving can cause the brake hoses to rupture and leak fluid.
The Risk
Vehicles use a dual-circuit system. If fluid escapes from a damaged front hose, it leads to a loss of hydraulic pressure in one of the circuits. While the backup circuit ensures the car can still stop, overall stopping performance will be significantly reduced, increasing stopping distances and raising the risk of a crash.
Affected Vehicles
This expanded action affects 2022–2025 model year vehicles in the flagship S-Class (223 platform) lineup:
- 2022–2025 Mercedes-Benz S 500 4MATIC
- 2022–2025 Mercedes-Benz S 580 4MATIC
- 2023–2025 Mercedes-Benz S 580 e 4MATIC
- 2022–2025 Mercedes-Maybach S 580 4MATIC
- 2022–2025 Mercedes-Maybach S 680 4MATIC
- 2024–2025 Mercedes-AMG S 63 E Performance
How Did the Investigation Unfold?
This update builds upon NHTSA Campaign 25V-116, originally filed in February 2025.
- The Initial Scope: MBAG initially attributed the brake hose failures to specific production windows and hot, humid regions where early cases were clustered.
- New Field Data: Between March and August 2025, MBAG received additional field reports from outside the U.S. involving vehicles operated in different climates and built outside the original production time frame.
- Engineering Review: MBAG launched a dedicated Field Engineering Activity in March 2026 to collect and analyze field components. Laboratory and durability testing completed in July 2026 confirmed that the risk applied to all vehicles produced up to the implementation of a redesigned brake hose in series production.
- Current Status: On September 25, 2026, MBAG officially decided to broaden the affected population. While three U.S. reports were identified between April and August 2026, there have been no reports of crashes, injuries, or property damage related to this condition.
Warning Signs to Watch For
Due to the nature of material fatigue, there are no advance warning signs before a leak develops.
However, if fluid loss occurs while driving:
- A red brake fluid warning message will display in the instrument cluster.
- You may notice increased brake pedal travel or reduced stopping power.
