Faults and Troubleshooting Methods of Chutian IPF85E Concrete Pump Truck

The reasons for the excessively high oil temperature in the hydraulic system of the Chutian IPF85E concrete pump truck and the solutions are as follows:

Improper operation caused the oil temperature to be too high

(1) The oil cooling fan is not turned on

Exclusion: Turn on the cooling fan.

(2) After the outrigger extension action was completed, the handle of the outrigger oil circuit and the boom oil circuit reversing valve was not turned back to its original position, causing the boom safety valve to remain in a high-pressure overflow state.

Exclusion: Return the handle of the reversing valve for the outrigger oil circuit and boom oil circuit to their original positions, that is, the unloading position of the safety valve.

(3) The handle of the water pump - air compressor steering valve is wrongly placed in the operating position of the air compressor. As domestic models are not equipped with air compressors, the hydraulic safety valve of the cooling system has been in a high-pressure overflow state at this time.

Exclusion: Place the reversing valve handle in the middle position.

(4) When pumping concrete over long distances in hot summer, due to the high pump resistance and the high oil pressure in the main oil circuit of the hydraulic system, if the discharge handle II is not set to the upper limit position at this time, the engine speed will be low, and the speed of the cooling fan will also be low, resulting in poor cooling capacity.

Exclusion: Set the exhaust volume handle II to the upper limit position and use the exhaust volume handle I to adjust the required displacement.

2. Poor heat dissipation leads to excessively high oil temperature

The hydraulic oil level in the oil tank is below the lower limit position

Exclusion: Replenish the same grade of hydraulic oil to the normal oil level.

(2) The water volume in the car wash tank is insufficient

Exclusion: Fill the car wash tank with water.

(3) The oil cooler is clogged inside or has a lot of dirt on its surface, resulting in poor ventilation.

Troubleshooting: Unclog the oil cooler and remove surface dirt.

(4) The opening pressure of the cooling safety valve is lower than the standard value, thus causing overflow and diversion, resulting in the fan speed being too low.

Exclusion: Adjust the opening pressure of the cooling safety valve to 6MPa.

3. The hydraulic oil has been contaminated and deteriorated

Observe the color of the hydraulic oil at the oil level gauge. If the oil has changed color or become opaque, it indicates that the oil has been contaminated.

Exclusion: Replace the hydraulic oil.

4. Improper pressure adjustment of the hydraulic system

If the system pressure is set too low, the safety valve will open frequently, causing overflow losses and leading to system overheating. If the system pressure is set too high, it will increase internal leakage, causing the hydraulic system to overheat.

Exclusion: Adjust the system pressure to the standard value.

5. Severe internal leakage causes the oil temperature in the hydraulic system to be too high

(1) Internal leakage of the hydraulic pump causes the system oil temperature to be too high

The symptoms of internal leakage in the main hydraulic pump include weak pumping power and reduced displacement. When adjusting the discharge volume handle I, there is no significant change in the displacement. At the same time, the pressure of the main hydraulic system is too low to reach the rated pressure value of the system. This symptom indicates that the main hydraulic pump has experienced internal leakage.

When the symptoms of internal leakage in the stirring pump include weak stirring, reduced speed of the stirring shaft, and the pressure of the stirring system failing to reach the standard value, it indicates that the stirring pump has experienced internal leakage.

Exclusion: Repair or replace the main hydraulic pump and the stirring pump.

(2) Leakage inside the hydraulic cylinder causes the oil temperature to be too high

Leakage can occur if the cylinder body of the main hydraulic cylinder or the slide valve drive cylinder is scratched or the piston seal inside the main hydraulic cylinder is damaged.

When the main hydraulic cylinder is in operation, the pumping displacement decreases, and the stroke of the main hydraulic cylinder automatically lengthens or shortens. When not in operation, the concrete piston slides down.

When the spool valve drives the cylinder to discharge symptoms during operation, the spool valve operates weakly. When the spool valve is locked with a ball valve outside of operation, the spool valve will automatically descend.

Exclusion: Replace the piston seals of the main hydraulic cylinder and the slide valve drive cylinder or the damaged cylinder body.

(3) Internal leakage of the hydraulic valve causes the oil temperature to be too high

Based on our repair experience, the main cause was severe wear of the pilot valve cores of the safety valves and sequence valves within the system, which led to leakage and overheating.

Symptoms: Overflow noise occurs and the system pressure drops. When touched by hand, the surface of the valve body feels abnormally hot.

Exclusion: Grind the valve core and valve seat, or replace them.

(4) Internal leakage of the stirring hydraulic motor causes the system oil temperature to be too high

Symptoms: Weak stirring, decreased speed of the stirring shaft, and overheating of the motor housing surface

Exclusion: Use square timbre to hold the stirring blades in the reverse direction, then remove the motor reverse return oil hose and turn the handle of the stirring reversing valve to the reverse position to observe the leakage. Then determine whether to repair or replace the stirring hydraulic motor based on the leakage situation. Atlas air compressor parts