There are 5 owner-reported brakes complaints for the 2018 Mercedes-Benz GLS-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
January 2023 - Airbag suspension failed. Replaced by Mercedes dealership. December 2024 - Airbag suspension failed. Replaced by Mercedes dealership. April 2024: First brake failure. The brakes stopped while driving. Repaired. April 2025: Second brake failure. Brakes failed again. Repaired. The mechanic stated the line was too close to the wheelbase, resulting in a pinpoint-sized hole. No warning lights. July 2025: Engine failure - the vehicle experienced a complete shutdown while driving with no warning lights. Vehicle in shop for 6-8 weeks for engine replacement by certified Mercedes mechanic. Post-engine replacement (July - Nov 2025) - Severe oil leaks at left cylinder head, small leaks at right cylinder head. Coolant warnings and overheating despite adequate coolant. Radiator and vent line issues. Active Brake Assist Limited warning appeared. Late November - Vehicle emitted smoke and experienced a small engine fire, observed under hood after stopping. Mercedes dealership deemed car unsafe to drive. During engine replacement wood pieces were found where destroyed motor mounts should have been. Multiple issues with no notice or warning lights.
Brake brakes are terrible. They have other years that they’ve acknowledge that the break are spongy and at times does not break the GLS has that defect. Also smell of gas fumes inside the vehicle. Please direct me the right way and help me with this issue. The brake issue almost have caused me two major accidents car doesn’t stop mechanic says this is a Mercedes issue You may contact me at [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Took vechicle for warranty repair of the frozen and suck both front calipers to Rallye mercedes dealer, repair was refused, car was noty drivable since brakes were stuck, still was kicked out of the dealership
The contact owns a 2018 Mercedes Benz GLS550. The contact stated that when the brake pedal was depressed there was an abnormal noise detected. The brake warning indicator light was illuminated. The contact stated that the brake pad on one side of the disc was completely worn, and the other side of the disc was like new with a full thick pad. The vehicle was taken to the local dealer and the contact was informed that the brake rotor needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure however, no further assistance was provided. The failure mileage was approximately 4,500. Consumer stated problem lies with the unevenness of the brake pad on both sides of the front wheels.
I WAS ALREADY 90% IN PARKING LINE WHICH IS HANDICAP'S. ABOUT TO STOP RIGHT FRONT OF HANDICAP SIGN, SUDDENLY VEHICLE START MOVING FORWARD WHILE MY FOOT WAS IN BRAKE SO I PUSH LITTLE HARD TO COMPLETE STOP BUT VEHICLE SUDDENLY ACCELERATE FORWARD SMASHING INTO THE BUILDING GLASS ENTRY WALL AND DOOR. I AM SO CERTAIN THAT MY FOOT WAS IN BRAKE. I WANT TO KNOW THAT IS THERE ANY WAY SOMEONE CALL OR VISIT WHERE BODY SHOP TO INSPECT THE VEHICLE SO I CAN ASK MANUFACTURE TO REPLACE MY VEHICLE.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026