In complex working conditions such as water conservancy projects, wetland management, and river dredging, amphibious excavators have become core equipment in the construction field due to their excellent environmental adaptability.

However, these devices are long-term subjected to the dual tests of high-intensity operation and harsh environments, making them extremely prone to high-temperature issues. Once the heat dissipation system fails, it will not only lead to a sharp drop in engine power and slow hydraulic system response but also may cause serious failures such as cylinder scoring and hydraulic oil carbonization, even resulting in equipment paralysis and safety accidents. This article provides a systematic heat dissipation and maintenance solution from three dimensions: high-temperature warning signal identification, emergency treatment technical solutions, and long-term maintenance management specifications.

Ⅰ. Identification of High-Temperature Warning Signals: Capturing Equipment “SOS Signals”

When amphibious excavators experience abnormal high temperatures, they usually release multiple warning signals through performance, instruments, and physical phenomena, which need to be comprehensively judged by combining multi-dimensional indicators:

1. Significant Performance Degradation: Engine output power decreases by more than 15%, hydraulic system movements slow down, and excavation efficiency is reduced by over 20%, showing obvious “powerlessness”.
2. Abnormal Instrument Warnings: The high-temperature alarm light on the dashboard turns on, the engine water temperature breaks through the 95°C warning line, the hydraulic oil temperature continues to exceed 80°C, and some models will trigger the automatic speed reduction protection mechanism.
3. Abnormal Physical Phenomena: The surface temperature of the radiator exceeds 85°C, which feels burning when touched; the color of the hydraulic oil darkens, the viscosity decreases, and even a pungent burnt smell appears; the engine is accompanied by metal friction noise during operation, and the cooling fan runs at a high frequency but with weak cooling effect.

Ⅱ. Technical Solutions for High-Temperature Emergency Treatment: Time-Critical “Cooling First Aid”

(A) Deep Cleaning and Maintenance of Radiators

As the “air conditioner outdoor unit” of the equipment, the heat dissipation efficiency of the radiator directly affects the temperature control of the whole machine, which needs to follow the principle of “precise cleaning and scientific protection”:

1. High-Pressure Flushing Operation: Use a 6-8MPa high-pressure water gun to flush reversely in the direction perpendicular to the radiator fins, focusing on removing blockages such as water plants, sediment, and oil stains. Maintain a safe distance of 15-20cm during flushing to avoid deformation of the radiator fins caused by water impact.
2. Deep Cleaning Treatment: For stubborn adherents, use special radiator fin cleaners (neutral pH) to soak for 5-10 minutes, and gently scrub with a soft nylon brush. It is strictly forbidden to use hard tools such as wire brushes to prevent damage to the fin structure.
3. Integrity Inspection: After cleaning, use compressed air (pressure 0.3-0.5MPa) to dry the residual water, check whether the radiator fins are or damaged, and promptly correct or replace the damaged parts with special tools.

(B) Refined Management of the Coolant System

The coolant system is the “core hub” for engine temperature regulation, and it is necessary to strictly implement the standards for liquid level monitoring, quality inspection, and replacement:

1. Dynamic Liquid Level Monitoring: Check the coolant expansion tank before daily operation to ensure that the liquid level is maintained between the MIN and MAX scale lines. If the liquid level drops abnormally, immediately check whether the water pump, pipeline, and water tank have leaks.
2. Professional Quality Testing: Use a freezing point tester and pH test paper to detect the performance of the coolant every 500 hours of operation. It is recommended to use ethylene glycol-based coolants that meet ASTM D3306 standards to avoid water tank corrosion and scale accumulation caused by using ordinary water.
3. Replacement and Maintenance Specifications: When the coolant is turbid or precipitated, or the boiling point is lower than 108°C, it is necessary to completely drain the old liquid, use a special cleaning agent to flush the cooling system cyclically, and fill in the same brand and specification of coolant. After replacement, carry out a pressure test (0.1-0.15MPa) to ensure that the system is leak-free.

(C) Optimization Strategy for Cooling Fan Efficiency

As a key component of forced heat dissipation, the cooling fan needs to be optimized simultaneously from three aspects: mechanical transmission, motor performance, and temperature control components:

1. Belt Tension Calibration: Use the thumb pressure method to detect the tension of the drive belt, with the standard deflection being 10-15mm. If the belt is loose or severely worn, replace it with an original specification belt and adjust the position of the tension pulley.
2. Performance Testing of Electric Fans: Use a multimeter to detect the resistance value of the motor winding. If it exceeds the rated range (±10%) or there is a short circuit, replace the motor immediately. At the same time, check the dynamic balance of the fan blades to avoid bearing damage caused by excessive vibration.
3. Maintenance of Temperature Control Components: For silicone oil clutch fans, test their engagement response time at ambient temperatures above 85°C (normal within 30 seconds). If there is a delay or no action, check the tightness of the temperature control valve and silicone oil chamber, and supplement special silicone oil.

Ⅲ. Long-Term Maintenance Management Specifications: Building Equipment “Health Protection Network”

(A) Construction of a Three-Level Inspection System

Establish a three-dimensional maintenance mechanism of “daily inspection, weekly inspection, monthly inspection”, and improve preventive maintenance capabilities by combining digital management tools:

• Daily Inspection: Before operation, check the tightness of hydraulic pipelines and coolant leakage, and record the engine starting temperature and initial pressure of the hydraulic system.
• Weekly Inspection: Use an infrared thermal imager to detect the temperature distribution of the radiator, analyze the pollution degree of the hydraulic oil through a hydraulic oil detector, and detect the pressure cycle efficiency of the heat dissipation system.
• Monthly Inspection: Carry out engine thermal balance tests, hydraulic system oil temperature tests, use a vibration analyzer to diagnose the operation status of components such as bearings and water pumps, and generate equipment health reports.

(B) Working Condition Adaptability Optimization Strategy

Dynamically adjust the construction plan according to the ambient temperature and operation intensity to reduce the equipment thermal load:

1. Dynamic Load Management: Avoid continuous full-load operation for more than 4 hours, and adopt an intermittent mode of “45 minutes of high-intensity operation + 15 minutes of idle operation” to allow the equipment to dissipate heat sufficiently.
2. Response to High-Temperature Environments: When the ambient temperature exceeds 35°C, reduce the excavation depth to 70% of the standard working conditions, reduce the frequency of steep slope operations and continuous slewing actions, and avoid simultaneous high-load operation of the engine and hydraulic system.
3. Ventilation System Maintenance: After operation, promptly clean up debris around the engine compartment and hydraulic oil tank to ensure that the air inlet grille and exhaust passage are unblocked. If necessary, install a dust-proof net to prevent foreign matter from invading.

(C) Full Life Cycle Management of Core Components

Implement preventive replacement and performance calibration for key components such as water pumps, thermostats, and radiators:

• Water Pump Maintenance: After the water pump bearing has been in operation for 2000 hours, even if there is no failure, replace the seals and bearings to prevent bearing corrosion caused by coolant leakage.
• Thermostat Calibration: Detect the opening temperature of the thermostat every year (standard opening temperature 82±2°C) to ensure that it can effectively close the large cycle at low temperatures and quickly open the heat dissipation channel at high temperatures.
• Radiator Maintenance: Use a special water tank cleaning agent for cyclic treatment every quarter to remove scale and rust and extend the service life of the radiator.

Conclusion

In the full life cycle management of amphibious excavators, high-temperature heat dissipation and maintenance are systematic projects deeply related to equipment performance, construction safety, and economic benefits. High-temperature failures will not only lead to shutdown losses and soaring maintenance costs but also may lay hidden dangers of mechanical structure damage, endangering the safety of operators.

Through the early warning mechanism, emergency strategies, and long-term maintenance system described in this article, construction enterprises can build a closed-loop management from prevention to disposal, effectively improving equipment reliability. In the future, with the popularization of intelligent operation and maintenance technologies, it is recommended to combine IoT sensors and big data analysis to achieve real-time monitoring and predictive maintenance of equipment temperature, promoting the intelligent and precise upgrading of the management mode of amphibious excavators and providing a solid guarantee for the high-quality development of water conservancy projects, ecological governance, and other fields.