Diagnostic method for walking weakness of model ZL50C loader
1 sets of Zheng Z L50C loader, its engine, working device and steering hydraulic system work normally, but its walking action is slow and weak, accompanied by torque converter and transmission oil temperature is high.
This type of loader torque converter and transmission is two independent assembly. When the failure occurs, the torque converter and gearbox are removed before disassembling and checking, which makes the maintenance efficiency low and the maintenance cost high. In this regard, we have in-depth study, decided not to disassemble the torque converter and transmission, by observing, testing and testing, diagnosis torque converter and transmission work whether there is a fault.
Fault diagnosis of 1. torque converter
(1) detecting the inlet and outlet pressure of torque converter
Converter inlet pressure valve of the pressure is 0.4~0.7MPa, the working pressure of oil outlet pressure valve for 0.25MP a. If the pressure is abnormal, should be normal to the value adjustment.
(2) check whether the torque converter output power
Start working loader operation if the engine is running normally and walk to, allows the loader to continue operations, and will increase the engine speed, rotation of the main drive to watch the converter to the transmission shaft, to determine whether the fault occurs in the torque converter. When the engine speed increases, if the main transmission shaft decreases or does not rotate, the torque converter fault can be diagnosed.
(3) observe the main drive shaft action
Put the high and low speed control handle in neutral position, let the engine run at medium speed, change the speed control handle in any gear, and turn in and back the control handle in the forward backward forward position repeatedly switch. The careful observation of action in reversing the main driving torque to the transmission shaft of the main transmission shaft, if instantaneous pause or slow down (about 1/2s) but immediately and quickly spin up, that the torque converter is normal; if the main drive shaft rotation weakness or long time no rotation is that torque is there a fault.
(4) listen to whether the torque converter has abnormal sound
In the process of diagnosis should listen attentively to the torque converter is a different sound. If the converter sends out abnormal sound, it may be the internal bearing damage, or the friction between the pump wheel, turbine and guide wheel. At this time, the oil of the oil pan can be checked. If there is a large amount of aluminum in the oil, it shows that there is abnormal wear in the converter, so the torque converter should be repaired immediately to avoid the damage of other parts.
(5) see if the torque converter is leaking
Check the respirator on the top of the torque converter housing. If there is oil leakage and if the loader is unable to work, it can be diagnosed as the damage of the frame oil seal at the wheel hub of the pump wheel. The disintegration of the torque converter, skeleton oil seal pump replacement wheel at.
2. transmission fault diagnosis
(1) detecting oil pressure
Put the transmission in and out of the control handle and speed control handle in neutral position, start the engine, check the speed of the oil pressure is normal. If the pressure is normal, we can check the following.
(2) no load check after hanging gear
Respectively, the inlet and back control handle and speed change control handle are placed in any position one by one, and carefully observe the pressure value corresponding to each gear, whether it is the same as the neutral pressure. If a low gear pressure, then prove that the gear clutch leakage. At this time only on the gear clutch seal can be replaced.
(3) load check after gear block
The loader is placed on the working site, and the bucket is laid flat and inserted in the mound, and the load test of the 3 gears except the reverse gear is carried out. The method is as follows: the high and low gear control handle is arranged in the high position, going in and out of control handle on a forward position, and the transmission handle in block I and III - neutral - I and III - transform between neutral gear. At this point, carefully observe whether the main drive shaft changes with the shift stop, spin - stop - rotation action. If the locomotive wheel is not rotated when the I gear or the third gear is loaded, the main drive shaft can rotate again, indicating that the gear is in fault. Other gear check methods are the same. In the inspection process can be 4 wheels fixed with 8 triangular wood, to prevent accidents.
(4) check the shift clutch
In the transmission, if the clutch piston is jammed, the friction plate is sintered and the butterfly spring is damaged, the clutch can always be in a state of constant engagement. Forward gear clutch has been in constant joint state, there are 3 aspects: one is the system of all gear pressure is normal; two is going in and out of the handle and the transmission handle in the neutral position, the loader can stop; three is on each gear power transmission normal loader, but when the gears are backward don't walk. This is because at this time, the 3 shift clutch at the same time, resulting in the transmission lock, resulting in transmission power can not be transmitted normally.
The same method can be used to judge whether the other 3 clutches are working normally. If a clutch is found to be out of order, the clutch can be decomposed and repaired.
Shift control valve of the brake off valve stuck in the off position, the pressure of each gear is normal, but they can not walk. At this time of the brake retaining valve for cleaning and maintenance.
