A concrete pump truck is a specialized concrete conveying machine with high mobility. It typically mounts a concrete pump on a specialized vehicle or truck chassis. It offers advantages such as high-quality pouring, fast construction speed, and labor savings, making it an essential component in construction projects. However, due to its complex operation and challenging structure, concrete pump trucks are prone to various malfunctions during operation.
1. Overheating of the Pumping System Hydraulic Oil: During continuous operation, concrete pump trucks often experience reversing pressure shocks, and the pumping system frequently reverses direction. Overheating is mainly caused by improper adjustment, maintenance, or operation of components, or by manufacturing and design flaws. Specifically, the following are possible causes: First, severe internal leakage in the hydraulic system; second, the relief valve is not unloading or the set pressure is too high; third, poor heat dissipation and excessive dust accumulation on the cooler fins; fourth, the cooler fan is not running; fifth, the cooler is blocked; sixth, the low-pressure relief valve is set too high or is damaged; seventh, the boom hydraulic system is not unloading; eighth, the hydraulic oil level is insufficient. When the oil temperature rises too quickly, or when the hydraulic oil temperature exceeds the normal operating temperature of 30℃～80℃, the cause of the fault should be identified and compared based on experience in order to take appropriate repair measures.
2 Common Faults and Troubleshooting of the Mixing System
2.1 Slurry Leakage in the Mixing System
Concrete pump trucks are generally equipped with lubrication devices to prevent cement slurry leakage at the
mixing shaft. Once slurry leakage is found at the mixing shaft, immediately check whether the oil filter is blocked,
whether there is oil in the grease pipe joints, whether the grease supply system is normal, and whether the grease
distribution valve has lost its distribution function. If the wear is due to the long service life of the mixing system,
the components should be replaced and effective maintenance should be performed in a timely manner.
2.2 Agitator Shaft Rotation Failure: If the agitator shaft stops rotating or its speed drops significantly, immediately
check if the hydraulic motor is working properly and if the hydraulic system pressure is within a reasonable range.
Alternatively, appropriately increase the agitator shaft speed.
3. Conveying Pipe Blockage and Clearing: Blockages in the concrete pump truck's conveying pipe mostly occur at
easily vibrating conical pipes and bends. Tap along the conveying pipe with a small iron rod. If the sound is crisp
and the conveying sound is a rustling sound, there is no blockage; if the sound is dull and the conveying sound is
harsh, there is a blockage. Symptoms include a gradual increase in conveying pressure, pumping stopping, no
decrease in hopper level, no discharge from the pipe outlet, pump vibration, and strong vibration and
displacement in the pipe. Reverse pumping is possible, but blockage reappears after switching to forward
pumping.
4. Proper Maintenance of Concrete Pump Trucks: Maintenance of concrete pump trucks mainly includes precision
checks, periodic inspections, regular maintenance, daily maintenance, and maintenance of the equipment cooling
system and lubrication system. Routine maintenance of concrete pump trucks must be standardized and
systematic, as this is the foundation of concrete pump truck maintenance. It is essential to adhere to concrete
pump truck maintenance procedures to extend the service life of the trucks and ensure a safe and comfortable
working environment. Simultaneously, it is crucial to improve the skills and qualifications of concrete pump truck
operators, which is key to effective management. Cultivating employee safety awareness, employing flexible and
diverse training methods for regular staff training, providing opportunities for further education, and
encouraging inter-departmental exchange are all vital to reducing the frequency of accidents.