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Winter Preheating Guide for Concrete Pump Trucks

Jun. 10, 2026

1. Necessity of Preheating

In cold winter, construction machinery is usually parked outdoors. For concrete pump trucks, preheating the engine before departure is mandatory. Besides, the on-board pumping system also needs preheating after arriving at the construction site.

Low temperature increases the viscosity of hydraulic oil and reduces its fluidity, resulting in higher flow resistance in pipelines. The hydraulic pump may suffer insufficient oil suction or cavitation. Poor lubrication will cause severe wear of pump components. Therefore, adequate preheating of the hydraulic system is essential before formal pumping operations, especially in winter with lower initial temperature.

The common preheating procedure is to engage the power take-off while the engine is running. The hydraulic pump operates passively until the oil temperature and viscosity reach the normal working range. Standard operation effectively reduces wear and failure rate of the hydraulic system, while improper operation will accelerate equipment damage.

Winter Preheating Guide for Concrete Pump Trucks

2. Standard Preheating for Main Hydraulic Pump

Working Principle

During idling operation, friction of bearings, valve plates and other components generates heat, which gradually warms up the hydraulic oil and lowers its viscosity. Adjust the swash plate of the hydraulic pump at a small angle to circulate the warm oil throughout the hydraulic circuit. The whole pumping system finishes preheating once the oil temperature reaches the rated value.

Operation by System Type

Open hydraulic system
Gradually increase the pumping displacement from zero. The directional valve works and hydraulic oil flows back to the tank to raise the overall oil temperature. Increase displacement step by step and keep each gear for 2 to 3 minutes. The whole process takes about 15 to 20 minutes until the normal working displacement is reached.
Closed hydraulic system
Start pumping at the minimum displacement and keep running for 5 to 8 minutes, then switch directly to the normal working displacement.

3. Preheating for Other Hydraulic Pumps

Other pumps include constant pressure pump, mixing pump, boom pump, and charge pump (for closed systems). Constant pressure pump and boom pump are swash plate piston pumps; mixing pump and charge pump are gear pumps. None of them support displacement or swash plate adjustment, so the preheating method for main pump is not applicable.

Keep the engine at idle speed in the early preheating stage. Most manufacturers require a 10-minute low-speed running before applying load. Do not raise engine speed prematurely during preheating. The lower the ambient temperature, the longer the no-load preheating time required.
In the later stage of preheating (for open systems), extend outriggers and booms, and start the mixer. This promotes oil circulation and backflow to the tank, so as to bring the overall oil temperature back to normal.

4. Supplementary Notes

Standard preheating operation greatly affects equipment failure rate, maintenance cost and operational safety.
This preheating method for main pumping system is also applicable to trailer concrete pumps, truck-mounted concrete pumps and other concrete pumping equipment.
All operations shall strictly comply with the provisions of the original equipment operation manual.

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