Water tank fire trucks play a critical role in firefighting operations, ensuring a stable and immediate water supply during emergencies. However, during long-term use, performance degradation or system failures may occur due to improper operation, insufficient maintenance, or natural wear and tear. To ensure optimal performance and operational reliability, regular maintenance and timely troubleshooting are essential. 1. Maintenance of Water Tank Fire Trucks Proper maintenance is the foundation for keeping a fire truck in peak working condition. Among all components, the centrifugal pump and priming system require particular attention. (1) Centrifugal Pump and Priming Device Maintenance 1. Lubrication Lubrication is essential for ensuring smooth pump operation and reducing wear: After every 4–6 hours of cumulative operation, check the gearbox oil level (if applicable). Refill immediately if the oil level has dropped. Use No. 18 hypoid gear oil as the recommended lubricant. Before operating the pump, inspect the oil level in the drive shaft bearing housing. Remove the oil level plug and fill oil through the inlet until it flows out of the level hole, then tighten the plug securely. It is recommended to replace the pump lubricating oil once per year. Apply grease regularly to the rear and middle supports of the pump shaft to ensure smooth rotation and prevent damage. 2. Drainage After Operation After each use: Drain all residual water from the pump and pipeline to prevent corrosion and freezing damage. Cover the inlet and outlet ports with protective caps. Apply grease to threaded connections to prevent rust and ensure easy disassembly. 3. Cleaning and Inspection Regularly remove carbon deposits from the exhaust priming device. Clean the water ring pump and its water tank monthly and replace with clean water. Ensure sufficient lubricating oil is maintained in the oil tank of piston-type or sliding-vane priming pumps. 4. Winter Protection During winter, antifreeze should be added to the water tank of the water ring pump. The antifreeze solution is typically a mixture of water and alcohol, prepared according to standard ratios to prevent freezing and ensure reliable operation in low temperatures. 2. Common Faults and Troubleshooting of Water Tank Fire Trucks Fault Phenomenon Cause Troubleshooting Method Priming device cannot reach maximum vacuum Poor friction wheel engagement Adjust Priming device cannot reach maximum vacuum Insufficient water in the tank Refill Vacuum gauge shows no vacuum or very low vacuum Poor sealing in suction pipeline Inspect and fix leaks Vacuum gauge shows no vacuum or very low vacuum Priming device malfunction Repair Vacuum gauge shows no vacuum or very low vacuum Strainer exposed above water surface Submerge into water as required High vacuum reading but no water intake Strainer check valve stuck Clear blockage High vacuum reading but no water intake Damaged suction hose Replace High vacuum reading but no water intake Pump inlet blocked Clean High vacuum reading but no water intake Excessive suction depth Reduce suction depth High vacuum reading but no water intake Strainer clogged with debris Clean Low discharge pressure with high vacuum Suction pipeline blocked Clean Low discharge pressure with high engine speed Flow exceeds pump rated capacity Reduce flow rate Low discharge pressure with low engine speed Engine malfunction Inspect and adjust Decreasing discharge pressure with increasing vacuum Gradual blockage in suction pipeline Clean Pump operates normally but pressure gauge shows no reading Pressure gauge damaged Replace pressure gauge Pump operates normally but pressure gauge shows no reading Pressure gauge passage blocked Flush the gauge passage Water discharge interrupted, pressure gauge needle fluctuates, engine speed increases Insufficient submersion depth of suction hose causing vortex and air intake Submerge strainer properly Water discharge interrupted, pressure gauge needle fluctuates, engine speed increases Engine malfunction Inspect and adjust No pressure reading, engine speed high Strainer exposed above water surface Submerge into water No pressure reading, engine speed high Loose suction hose connection Reinstall and tighten



