The common faults of hydraulic torque converters for loader parts are: oil temperature is too high, oil supply pressure is too low, oil leakage, machine travel speed is too low or travel is weak, and abnormal noises are announced during operation.
1. The oil temperature is too high
Excessive oil temperature is manifested when the oil temperature gauge exceeds 120 ° C when the machine is in operation or feels tangy when touched by hand. There are several reasons: the transmission oil level is too low; the water level in the cooling system is too low; the oil pipe and the cooler are blocked or Too dirty; the torque converter is too long to operate in the low efficiency range; the fastening screws of the work wheel are loose; the bearing cooperation is loose or damaged; the integrated hydraulic torque converter is locked due to the free wheel jamming; when the guide wheel device The free wheel organizes short parts.
The diagnosis and removal methods of excessive oil temperature of the torque converter are as follows: when the oil temperature is too high, the parking should be immediately carried out and the engine should be operated at idle speed to see if the cooling system is leaking and the water tank is filled with water; if it is cooled If the system is normal, you should check whether the transmission oil level is between the two symbols of the dipstick. If the oil level is too low, the oil of the same brand should be made up; if the oil level is too high, it is necessary to drain the oil to the proper oil level. If the oil level meets the requirements, the machine should be adjusted so that the torque converter operates within the high-efficiency zone, and try to prevent long-term operation in the inefficient zone. If the oil temperature is still too high after adjusting the operating conditions of the machine, check the temperature of the oil pipe and the cooler. If the temperature is low when touched by hand, it indicates that the oil drain pipe or the cooler is blocked or too dirty. The oil drain pipe should be removed to see if there is any The sediment is blocked. If there is any sediment, it should be shoveled out, and then install the joint and seal the drain pipe. If you feel the temperature is very high when touching the cooler, a small amount of oil should be discharged from the torque converter housing for inspection. If there is metal dust in the oil, explain that the bearing is loose or damaged, resulting in wear of the work wheel. It should be differentiated, replace the bearing, and check whether the tightening bolts of the pump wheel and the pump hub are loose. If they are loose, they should be tightened. The above items are normal, but when the oil temperature is still high, you should check whether the operation of the guide wheel is normal. Fully open the engine throttle so that the torque converter is at zero speed. After the oil temperature at the outlet of the torque converter has risen to a certain value, replace the torque converter with the hydraulic coupling. Investigate the degree of oil temperature drop. If the oil temperature drops slowly, it may be because the free wheel is stuck and the guide wheel is locked. The torque converter should be disassembled to check.
Kobelco loader accessories
2. The oil supply pressure of the loader parts is too low
The phenomenon is: when the engine throttle is fully open, the inlet oil pressure of the torque converter is still less than the specification value. Mainly caused by the following reasons: low oil supply, oil level is lower than the level of the oil suction port; leakage or blockage of the oil pipe; too much oil flowing to the transmission; blockage of the oil inlet pipe or oil filter; severe wear or damage of the hydraulic pump; oil absorption The filter device is not appropriate; the oil foams; the inlet and outlet pressure valves cannot be closed or the rigidity of the tension spring is reduced.
If the oil supply pressure is too low, the oil level should be checked first: if the oil level is lower than the minimum scale, the oil should be compensated; if the oil level is normal, the oil inlet and outlet pipes should be checked for leakage, and if there is oil leakage, the oil should be removed . If the inlet and outlet pipes are well sealed, check the operation status of the inlet and outlet pressure valves. If the inlet and outlet pressure valves cannot be closed, remove them to see if there are any cracks or scars on the parts, whether the oil passages and oil holes Unblocking, and whether the stiffness of the tension spring becomes smaller, the problem should be dealt with in time. If the pressure valve is normal, remove the oil pipe or filter to check. If there is a blockage, it should be cleaned and shoveled away. If the tubing is cleared, the hydraulic pump should be checked, and the hydraulic pump should be replaced if necessary. If the hydraulic oil foams, you should check the condition of the oil return pipe. If the oil level of the oil return pipe is lower than the oil level of the oil sump, you should reinstall the oil return pipe.
3. Leakage of torque converter
The oil leakage of the torque converter is mainly caused by the loosening of the connecting bolts of the torque converter back cover and the pump wheel, the connection between the pump wheel and the hub, or the aging or damage of the seal. If an oil leakage is found, the engine should be started and the oil leakage area should be checked. If there is oil leakage from the connection between the torque converter and the engine, it is clarified that the connection bolts of the pump wheel and the pump wheel cover are loose or the seal ring is aging. Tighten the connection bolt or replace the O-ring seal; if the connection between the torque converter and the transmission is thrown away Oil, clarify that the connection bolt between the pump wheel and the pump hub is loose or the seal ring is damaged. Tighten the bolt or check the seal ring; if the oil leakage part is in the direction of the oil filler or oil drain, check the tightness of the bolt connection and whether there are cracks, etc. .
4. The speed of the machine is irregularly low or weak
This fault is mainly caused by the following reasons: the internal seal of the torque converter is damaged, which causes the fluid flow impact of the working chamber to drop; the free wheel organization is stuck, forming a guide wheel lock; the free wheel wear failure; the work wheel blade Damaged; inlet and outlet pressure valves damaged; hydraulic pump worn, lack of oil supply; hydraulic oil level is too low; transmission friction main clutch is defective.
After starting the gear, if the travel is weak or slow, you should first check whether the indicated pressure of the gear pressure gauge is within the normal range. If the pressure is too low, you should sweep it out; if the pressure is normal, it may be that the free wheel wears out or works The wheel blade is damaged; there may also be a problem with the transmission friction clutch, which should be analyzed and removed.
5. Abnormal noise when the torque converter is in operation
This problem is mainly caused by the bearing or damage, loose connection of the working wheel or loose connection with the engine. In such a situation, you should first check whether the connecting parts are loose, and then check the bearings. If there is any looseness, you should adjust or replace the new bearing. In addition, the amount and quality of hydraulic oil should be checked, and new oil added or replaced if necessary
