I. After-sales clauses in the contract: How to design them to avoid disputes? In a tender project for Dongfeng double-cab sewage suction trucks (blue license plate, 3 m³) procured by a municipal sanitation department in Guangdong Province, after-sales clauses served as a key scoring item during evaluation. According to the 'Government Procurement Law' and local implementation practices, standard after-sales clauses in such contracts typically include the following core provisions: Warranty period requirements: Full-vehicle warranty of no less than 1 year or 20,000 km (whichever occurs first); chassis components must comply with the original manufacturer’s three-warranty policy. Response time: Suppliers must respond by phone within 2 hours of fault reporting and dispatch technicians to the site within 24 hours (for Foshan City and surrounding areas). Spare parts supply: A list of commonly used wear-and-tear parts must be provided within 7 days after contract signing, with a commitment to ship orders within 24 hours. Training services: On-site training for at least two operators upon vehicle delivery, covering routine maintenance, safe operation, and troubleshooting common faults. Special operating condition assurance: Given Guangdong’s hot and humid climate, suppliers must apply anti-corrosion coating to both chassis and superstructure, and guarantee free replacement of components damaged due to corrosion during the warranty period. Additionally, durability test reports for sealing components must be provided to ensure reliability under high-frequency rainy-season operations (average daily operating time exceeding 6 hours). These clause designs directly address real-world pain points encountered by municipal sanitation vehicles in the region—metal corrosion caused by high temperature and humidity, accelerated aging of sealing components during rainy seasons, and component wear on chassis and superstructure under heavy-duty operation. II. Common types of after-sales disputes: The 'invisible killers' in hot-humid environments Based on Chengli Special Purpose Vehicle’s service experience across more than 500 municipal sanitation units, after-sales disputes in southern regions such as Guangdong primarily fall into the following three categories: Chassis and superstructure corrosion: Although Dongfeng chassis are factory-produced, insufficient specialized anti-corrosion treatment leads to rust spots appearing on chassis beams, subframes, and bolted joints within 3–6 months in coastal cities like Foshan and Guangzhou—severely compromising structural integrity. Sewage suction trucks face even higher corrosion risks due to frequent contact with wastewater and sludge. Sealing component failure causing leakage: Sealing components in hydraulic systems, sewage tank openings, and discharge valves age faster in hot-humid conditions. If seal materials lack heat resistance and oil resistance, hydraulic oil leakage or sewage seepage may occur during rainy-season operations—reducing operational efficiency and exposing users to environmental regulatory penalties. Component fatigue under high-load operation: During rainy seasons, sewage suction trucks may operate 8–10 hours per day. Prolonged high-load operation of hydraulic pumps, multi-way valves, and power take-off (PTO) units—without regular maintenance or genuine OEM parts—easily results in breakdowns and operational downtime. To address these issues, Chengli Special Purpose Vehicle emphasized the following after-sales commitments in its bid proposal for the Foshan project: III. Chengli’s Lifetime After-sales System: From 'Three-Warranty' to 'Full Lifecycle Support' For government procurement projects, Chengli Special Purpose Vehicle offers a dual-protection model: 'Nationwide Dongfeng Chassis Warranty + Lifetime Superstructure Service'. Specific provisions include: Chassis nationwide warranty: Dongfeng chassis are covered under a nationwide warranty network comprising over 2,000 authorized s