The high temperature in summer is a "major test period" for the cooling system. Negligence in maintenance may cause a chain of failures. The following hidden dangers need to be emphasized for prevention.

I. Crisis of coolant performance degradation
Risk point

Boiling point drop: The common coolant boils at 105℃, while the long-lasting type can maintain it at 129℃.
Corrosion intensification: Poor-quality coolant can cause perforation in the copper tubes of the radiator.
Maintenance suggestions
Replace the coolant every two years and use a refractometer to measure the freezing point (below -35℃).
Before adding the leak repair agent, the system must be thoroughly flushed to prevent chemical reactions from blocking the waterways.
Ii. The Disaster of radiator blockage
Typical case: An SUV broke down at a highway service area. Upon inspection, it was found that the radiator was 90% clogged with willow catkins, causing the engine to pull the cylinder.
Cleaning tips

Use a high-pressure air gun to blow from the inside out, with the pressure controlled at 0.2MPa.
When performing chemical cleaning, use a neutral cleaning agent with a pH value of 6 to 8, and the soaking time should not exceed 15 minutes.
Iii. Overload Risk of Electronic Fans
Data Alert

After continuous high-speed operation for more than 20 minutes, the motor temperature can reach 140℃.
According to statistics from a certain brand of vehicle models, the failure rate of electronic fans in summer is 3.7 times that in winter.
Preventive measures
Regularly clean the dust accumulated on the fan blades to ensure there is no obstruction within 30cm of the air intake.
Upgrade the heat sink of the fan motor, increasing its surface area by 40%.
Iv. Hidden dangers of Belt Drive System
Key points for inspection

Measure the tension of the belt: Press with a force of 10kg, and the deflection should be 10-15mm.
Observe the edge of the belt: If cracks or fuzzing appear, replace it immediately.
Case: A taxi's fan stopped rotating due to a broken belt, and the engine overheated and was scrapped within 10 minutes.
V. Golden Rules for Emergency Response
Overheating treatment
Immediately turn on the hazard lights and slow down to below 60km/h.
Open the hood to assist with heat dissipation, but do not water directly.
Coolant replenishment
The same brand of coolant must be used. Mixing them will cause sedimentation.
In an emergency, pure water can be added, but it needs to be completely replaced later.
Trailer specifications
Automatic transmission vehicles must use flatbed trailers.
For manual transmission vehicles, the speed limit is 30km/h and the distance should not exceed 50km.
Conclusion: The maintenance of cooling fans requires the establishment of a three-level system of "prevention - monitoring - emergency response". Through regular inspections (every 5,000 kilometers), data monitoring (OBD-II reading), and emergency plans, the risk of engine overheating can be reduced by 82%. Remember, a single oversight in maintenance may result in tens of thousands of yuan in repair losses and may even endanger driving safety.