1. What should you watch out for when assembling the drive shaft? Answer: In order to ensure that the drive shaft can be assembled in its original position after being disassembled, it must be marked before disassembling. When assembling, care should be taken to ensure that the universal joints at both ends of the drive shaft are in the same plane, and that the spline grooves and expansion joints of the drive shaft do not change. 2. How to remove the single-acting cylinder piston? A: The single-acting cylinder piston can be disassembled in the following two ways: (1) The piston is pressed out of the cylinder sleeve with compressed air. Compressed air should be compressed from the inlet port of the cylinder (usually a bicycle pump), and the other infusion ports should be blocked to prevent gas leakage. (2) When the piston seal is severely damaged and it is difficult to disassemble it with compressed air, the cylinder port can be turned downward and the piston can be pulled out on the wood. 3, how to determine the hydraulic brake failure? Answer: (1) When the brake pedal is pressed continuously, if the pedal can gradually rise and feels elastic when continuing to step on the next step, there is air in the brake system and it should be eliminated. (2) If the brake pedal is continuously pressed and the pedal is raised, but continues to step down, there is a feeling of pedal rise. This indicates that there is oil leakage in the pipeline, joint, or the main pump and the branch pump. (3) If the pedal height is appropriate, there is no sense of elasticity and sinking when stepping down, but the braking effect is poor, it is a defect of the brake hub and the brake friction plate. If the friction plate is stained with oil and the rivet is exposed, it will The braking force is weakened, and brake failure, blockage of main pump vents, and compensation holes can also cause brake failure. (4) If the brake pedal does not work, but the pedal is raised for a few moments, there is no elastic feeling, indicating that the pedal free stroke and brake clearance are too large and must be adjusted. 4, hydraulic brake for the delay there? Answer: Braking delay means that all or part of the wheel still produces braking effect when the brake pedal is raised after braking. The reason is: (1) The brake pedal does not have a free stroke, or the pedal return spring falls off, becomes too soft or breaks. (2) The hydraulic pump cylinder blocks the balance hole and cannot return oil or return, or the hydraulic pump bowl swells, embolism does not work, and it cannot return after braking. (3) The gap between the friction plate and the brake hub is too small to cause rubbing, or the spring of the shoe return spring breaks and fails. (4) The brake shoe bearing pin is contaminated and the brake shoe cannot rotate freely. After traveling for a distance, if all the wheels are found to be hot, it means that the fault is in the main pump. If any individual wheel is hot, the fault is on the wheel and should be promptly eliminated.