Failure Analyce & Trouble shooting：The fault is that the power cannot be taken, the  equipment can not operate normally, and the electrical, pneumatic, and  mechanical parts are gradually checked.

Repair Procedure：1. After the on-site inspection  operation, the equipment can still be in the driving state, so as to conclude  that the force is not switched. 

2. Check the line: It is found that the force  rocker switch is pressed, and the instrument panel lights up the power  indicator light to eliminate the line. 

3. Measure the coil resistance of the  solenoid valve at both ends of the two-position five-way valve, and the  resistance is normal. 

4. Gradually pull out the two-way five-way valve to the  power take-off tube to check that the air path is normal, so as to eliminate  the two-way five-way valve and gas path failure. 

5. Disassemble the rear end  cover of the power take-off, and find that the switching piston is stuck and  can not move normally. Clean the inner wall of the piston on site, replace  the O-ring and fill the lubricating oil repeatedly, and the installation and  debugging are normal and the fault is eliminated.

Principle & Expierence Summary：This type of fault is mostly caused  by line faults and the failure of the two-position five-way valve. It is  extremely rare to take force to switch the piston.