Three minutes can solve the high temperature of hydraulic oil!
May 31, 2022
The high temperature of hydraulic oil has always been a headache for excavator masters. Recently, many excavator masters have received help information about high temperature of hydraulic oil. So how to effectively solve the stubborn problem of high temperature of hydraulic oil? The following engineers explain to you! Many excavator masters believe that external contamination of the hydraulic oil radiator (oil cooler) and debris in the interlayer between the hydraulic oil radiator and the water tank are the main reasons for the high temperature failure of the hydraulic oil. In fact, it is not. The failure of the oil return check valve (back pressure valve) is the "culprit" that really causes the high temperature of the hydraulic oil. If the high temperature of the hydraulic oil is not dealt with in time, it will cause the main pump, main control valve and various working devices in the long run. If the internal leakage is serious, it must be repaired or replaced. The function of the oil return check valve is to make the return oil pressurized enough to compensate for the possible cavities in the system, and to prevent excessive oil return disturbance or shock from damaging the hydraulic oil radiator. The oil return check valve is a device for the hydraulic oil to return to the hydraulic oil tank from the main control valve to the working device. There are generally two devices, one is installed between the main control valve and the hydraulic oil tank, and the other is installed in the main control valve. between the valve and the hydraulic oil radiator. The pressure of the two oil return check valves is also different. The pressure of the oil return check valve on one side of the hydraulic oil tank is 0.5MPA/5BAR (maximum 0.5-0.3MPA) (different tonnage pressure), while the other side The pressure of the oil return check valve to the hydraulic oil radiator is 0.15MPA/1.5BAR (0.3-0.15MPA) (different tonnage and pressure).
When the hydraulic oil has a high temperature alarm, the oil return check valve opening on one side of the hydraulic oil tank is stuck or damaged, which will cause the hydraulic oil to return directly to the hydraulic oil tank without passing through the hydraulic oil radiator, resulting in abnormally high temperature. Note: (The hydraulic oil is not replaced for a long time, the quality of the hydraulic oil is poor, and too much impurities in the hydraulic oil will cause wear or damage to the oil return check valve, and in severe cases, it will also cause damage to the hydraulic pump, main control valve and working devices, so Hydraulic oil must be replaced on time in daily maintenance to prevent wear of hydraulic components). 
The pressure of the oil return check valve on the oil return tank side is higher than that of the oil return check valve on the hydraulic oil radiator side. When purchasing, it must be purchased and installed according to the standard pressure of the original factory. The pressure of the oil check valve is lower than that of the radiator side, and the hydraulic oil is directly returned to the oil tank, which will also cause the hydraulic oil temperature to be too high. If the two oil return check valves are not installed or removed, not only high temperature, but also the hydraulic oil radiator will often be damaged due to excessive return oil pressure, because the return from the main control valve to the hydraulic oil radiator side The oil check valve is damaged or not installed (Note: Generally, the copper radiator can withstand the pressure of up to 3BAR, and the aluminum radiator can withstand the pressure of up to 20BAR, so when buying a new radiator, it is best to look at the material of the original radiator, don't buy it It burst and leaked oil not long after I came back and installed it). Tips I also remind everyone here that there are many brands of oil return check valves in the market, but the price of the original factory is relatively high; and because its production process is relatively simple, domestic manufacturers can meet the technical requirements, so the oil return produced by domestic hydraulic manufacturers The quality of the one-way valve is still very good. For example, the price of the domestic oil return check valve for a 5-8 ton excavator is about 100 yuan, which is a reference for all bosses.
