2021 Mci D4520 technical service bulletins

Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.

• Aug 11, 2026 Service bulletinThis bulletin is to provide instructions for clearing DTC 1067 FMI 7 (Pressure Sensor Not Calibrated) and...
• Jun 11, 2026 Service bulletinThis bulletin introduces an optional product improvement to the A/C compressor drive system for coaches...
• May 6, 2026 Service bulletinThis TSIB provides information to provide a software update
• Feb 9, 2026 Service bulletinThis TSIB is to inform customers the recommended steering axle cleaning/greasing instructions to prevent...
• Nov 5, 2024 Service bulletinInformation to owners showing the proper procedure for checking the oil level in a BITZER HVAC compressor.
• Jul 17, 2024 Service bulletinService instruction for updating plug doors to improve reliability and reduce wind noise.
• Feb 10, 2023 Service bulletinInstructions to properly adjust entrance door to ensure proper operation.
• Feb 2, 2023 Service bulletinInstructions for improving fuel tank venting while fueling.
• May 3, 2022 Service bulletinTechnical Service Information Bulletin describing the retrofit for the front junction box cover on...
• Apr 1, 2022 Service bulletinThis Technical Service Information Bulletin is a supplemental reminder to all MCI owners/operators of...
• Dec 14, 2021 Service bulletinThis Technical Service Information Bulletin (TSIB) describes an update from Meritor for the bolt torque...