Start with the business license: every legitimate Chinese company has a Unified Social Credit Code. Ask for a copy and verify it on the National Enterprise Credit Information system or via your freight forwarder. Check that the business scope includes 'used car export'—this requires specific qualifications. Next, look for proof of substance: a real office or yard (verify via live video call, not pre-recorded), staff answering on Chinese business platforms like WeChat with consistent branding, and a corporate bank account in the company's name—never pay a personal account. Cross-check trade history: ask for recent shipping documents (blurred bills of lading with customer info hidden), references from buyers in your region, and whether they hold export licenses issued by Chinese commerce authorities. Red flags: prices far below market, pressure to pay quickly, refusal of video calls, or bank accounts in third countries 'for convenience'. Take your time—real exporters pass these checks easily.

The technician will start the vehicle and turn on the air conditioning system, measuring the actual temperature at the vents at the lowest and highest settings with a thermometer; at the same time, they will connect a manifold pressure gauge to check if the refrigerant pressure in the high and low pressure lines is within the normal range, determining if there is a chronic refrigerant leak.

All our measuring instruments (especially calipers, paint thickness gauges, and refrigerant pressure gauges) are calibrated quarterly according to ISO quality management system requirements to ensure the data we provide you is objective, accurate, and reliable.