Government procurement case of Dongfeng single-cab sewer cleaning truck (blue license plate, 5 m³) in Xiamen: 3-year failure rate analysis and bid-winning solution interpretation. In early 2023, a municipal sanitation department in Xiamen publicly tendered for a batch of Dongfeng single-cab sewer cleaning trucks (blue license plate, 5 m³), with a budget cap of approximately RMB 313,000 per unit. Chengli Special Purpose Vehicle Co., Ltd. secured the contract and delivered five units at an average unit price of around RMB 265,000 (per publicly available tender information). As of February 2026, these vehicles have been in operation for nearly three years. This article conducts an in-depth analysis—based on authentic maintenance records—across dimensions including fault type distribution, adaptability to hot-humid environments, after-sales response speed, and spare parts supply assurance, while also interpreting the procurement strategy to provide reference for similar organizations. I. Three-Year Authentic Maintenance Records: Fault Type Distribution and Data Interpretation The five Dongfeng single-cab sewer cleaning trucks (model series referenced from CLW5070GSSD6 official derivative announcements) entered service in March 2023, primarily undertaking sewer pipe cleaning and routine maintenance operations during Xiamen’s rainy season (May–September). According to repair work orders logged in Chengli’s after-sales service system (as of February 2026), a total of 23 fault reports were recorded, categorized as follows: Hydraulic System Failures (8 incidents, 34.8%): Primarily involving sluggish lifting motion of the cleaning boom and hydraulic hose leakage. Among these, three incidents resulted from accelerated aging of hydraulic hose fittings under hot-humid conditions; two were caused by operator error leading to seal ring damage. Engine and Chassis-Related Failures (5 incidents, 21.7%): Including one incident of unstable engine idling (resolved by replacing the fuel filter), two cases of clutch plate wear (linked to frequent start-stop operations), and two tire punctures. Sewer Cleaning Equipment Failures (6 incidents, 26.1%): Including three suction inlet blockages (caused by ingestion of oversized debris during operation), two vacuum pump seal failures (occurring after continuous high-load operation), and one leak at a pipeline connection joint. Electrical and Control System Failures (3 incidents, 13%): Including two sensor false alarms (resolved after cleaning) and one control panel contact failure (resolved by module replacement). Body Corrosion and Sealing Issues (1 incident, 4.4%): One vehicle exhibited minor corrosion at a weld seam near the rear of the sewage tank following the end of the 2025 rainy season (resolved by Chengli’s after-sales team applying anti-corrosion coating). Distribution analysis shows that hydraulic system and sewer cleaning equipment failures accounted for the highest proportion (combined 60.9%), directly reflecting the high-intensity, high-frequency operational nature of sewer cleaning trucks. Notably, under hot-humid conditions (Xiamen’s annual average relative humidity is ~80%), durability of hydraulic hose fittings and sealing components emerged as critical performance determinants. II. Specialized Performance in Hot-Humid Environments: Anti-Corrosion Coating and Seal Durability Xiamen features a subtropical maritime climate characterized by high temperature, high humidity, and severe salt fog corrosion—imposing stringent requirements on vehicle corrosion resistance and sealing performance. For this batch of sewer cleaning trucks, Chengli implemented the following environment-specific configurations at the factory stage: Enhanced Anti-Corrosion Coating: The tank body and cleaning boom utilize epoxy zinc-rich primer plus polyurethane topcoat, with a total dry-film thickness exceeding 120 μm. Based on three-year usage records, only one vehicle exhibited minor corrosion at a weld seam…