2021 Mercedes-Benz AMG GT Brake System Update

Why This Field Measure Matters

Mercedes-Benz has issued Field Measure 21P4396101 to ensure that the front axle brake system on affected 2021 Mercedes-Benz AMG GT models meets the latest series production standards. This proactive update is crucial for maintaining the vehicle's intended performance and safety characteristics, especially for high-performance variants like the Black Series.

Ensuring all components are up to current specifications helps prevent potential issues that could arise from outdated parts or configurations. This measure reflects Mercedes-Benz's commitment to vehicle quality and owner satisfaction for the Mercedes-Benz AMG GT brake system update.

Important Warnings and Advisories

Owners and technicians should be aware of several critical instructions during this procedure:

• "All screws must be replaced!" This warning is repeated throughout the procedure for various components, including the lower engine compartment lining, front bumper, radiator protection grille, holders, and rotational speed sensors.
• "Left and right front fender liners are no longer needed (will be replaced)!" and "The air ducting is no longer needed (will be replaced)!" indicate that these specific parts are being permanently removed and superseded by new designs.
• "The right holder is no longer needed (H, Figure 10)." refers to a specific component being eliminated from the assembly.
• When removing the brake caliper, technicians are explicitly warned: "Do not open hydraulically!" This prevents damage to the brake system.
• During the installation of heat protection for the rotational speed sensors, it's advised: "Do not wrap heat protection around too tightly – leave a small air gap for optimized insulation."

Overview of the Brake System Update

This field measure, identified as 21P4396101, focuses on comprehensively updating the front axle brake system and surrounding components for the 2021 Mercedes-Benz AMG GT, specifically Model 190 with M032 (Black Series). The update involves replacing numerous parts, including hoses, air ducting, holders, brake cover plates, and guide vanes, to align the vehicle with current production configurations. The process also includes critical steps like wrapping heat protection around speed sensors and bleeding the low-temperature circuit.

Detailed Repair Procedure Summary

The extensive procedure for the Mercedes-Benz AMG GT brake system update involves 31 steps, requiring significant disassembly and reassembly of the front end of the vehicle. Key steps include:

1. Preparation: Removal of both front wheel and tire assemblies, lower engine compartment lining, front and rear fender liners, front bumper, radiator protection grille, and air ducting.
2. Component Removal: Disassembly continues with the removal of three specific holders with struts, left and right impact foam pieces, top heat shields, and front axle rotational speed sensors.
3. Hose and Air Ducting Modifications: The left low-temperature water hose is extended using adapter A 190 501 67 00, and the low-temperature circuit is checked for leaks. New air hoses, part number A 190 428 31 00, are installed on both sides, ensuring correct positioning of color markings.
4. Holder and Grille Installation: Horn holders are removed, and the right horn is attached to a new holder (A 190 501 66 00). A supplied edge guard is mounted, followed by the installation of new right and left holders with horns onto new air ducting (A 190 505 36 00). The new air ducting is then connected with air hoses.
5. Brake System Work: The brake caliper and brake disk are removed. Heat protection (A 004 997 08 51), cut to 150 mm and secured with cable ties (A 000 995 97 06), is wrapped around the removed front axle rotational speed sensors before they are reinstalled.
6. New Component Installation: New brake cover plates (A 190 421 47 01 / A 190 421 48 01) and screening plates (A 190 421 67 01 / A 190 421 68 01) are installed. Front guide vanes (A 190 421 43 01 / A 190 421 44 01) and rear guide vanes (A 190 421 51 01 / A 190 421 52 01 / A 190 421 45 01 / A 190 421 46 01) are replaced.
7. Reassembly and Final Steps: The front bumper is reinstalled, along with new front fender liners (A 190 690 01 02 / A 190 690 02 02) and new connection fittings (A 190 885 65 04 / A 190 885 66 04) at the wheel well liner. The lower engine compartment lining is reinstalled. Finally, the low-temperature circuit coolant is filled and bled using a diagnostic system, with a mixing ratio of 40:60.

This comprehensive process ensures the 2021 Mercedes-Benz AMG GT brake system update is completed to factory standards.

Required Parts and Materials

This field measure requires a substantial list of new parts to complete the Mercedes-Benz AMG GT brake system update. Key components include:

• Hoses and Ducting: Adapter A 190 501 67 00, flexible air hoses A 190 428 31 00, new air ducting A 190 505 36 00.
• Holders and Brackets: New holder A 190 501 66 00 for the right horn, new right and left holders for horns.
• Brake Components: New brake cover plates A 190 421 47 01 / A 190 421 48 01, screening plates A 190 421 67 01 / A 190 421 68 01, front guide vanes A 190 421 43 01 / A 190 421 44 01, rear guide vanes (multiple part numbers: A 190 421 51 01, A 190 421 52 01, A 190 421 45 01, A 190 421 46 01).
• Fender Liners and Fittings: New front fender liners A 190 690 01 02 / A 190 690 02 02, new connection fittings A 190 885 65 04 / A 190 885 66 04.
• Fasteners and Miscellaneous: Heat protection A 004 997 08 51, cable ties A 000 995 97 06, and numerous screws, bolts, nuts, and expansion rivets (e.g., A 010 990 26 04, N 304017 006028, A 000 990 28 62, etc.) as detailed in the full parts list.

Owner Action

If you own a 2021 Mercedes-Benz AMG GT, particularly a Model 190 with the M032 (Black Series) designation, it is recommended to contact your authorized Mercedes-Benz dealership. Inquire about Field Measure 21P4396101 to confirm if your vehicle is subject to this front axle brake system update. This is a proactive measure to ensure your vehicle's brake system meets current production standards. The work procedure, identified by operation number 02-0682 and damage code 43 961 01, is performed by the dealership.

NHTSA ID: 10208673