1.insufficient braking pressure
Fault phenomena:
A brake failure due to insufficient air pressure is when the air pressure does not reach the required air pressure (0.45-0.70 MPa) and there is no braking response when the brake pedal is pressed.
Causes of failure:
1)leakage in the pipeline and insufficient pressure or low pressure in the gas storage cylinder may contribute to the lack of braking force.
2)The air compressor is experiencing malfunctions, preventing it from generating an adequate amount of compressed air.
3)The one-way valve is corroded and stuck, which makes it impossible to intake air into the gas storage cylinder or slow intake.
4)The oil releasing screw of the oil-water separator is not securely tightened, resulting in a significant leakage issue.
5)The pressure regulating valve leaks seriously.
Troubleshooting:
First, begin by inspecting the pipeline for any signs of leakage. Then, assess the condition of the air compressor. Detach the air compressor outlet pipe and place your thumb on the outlet. If the exhaust pressure is low, it indicates a malfunctioning air compressor. Next, examine the oil releasing screw plug or pressure regulating valve of the oil-water separator. Ensure they are securely fastened to prevent any bypassing. Lastly, check the two one-way valves located in the three-way joint. If any of the one-way valves are stuck, it can lead to an inability to enter the air storage cylinder or slow intake.
Brake failure
Fault phenomena:
The loader is unable to slow down and come to a stop while it is running.
Causes of Failure:
1) Insufficient brake pressure results in the inability to drive the piston action of the brake.
2) Brake valve failure, piston jam, or blockage in compensation hole and air hole leads to inadequate air pressure generation.
3) Presence of air in the brake oil pipe causes fluctuating oil pressure, insufficient flow, and inability to drive the piston action of the brake.
4) Insufficient or no brake fluid causes low output power in the brake cylinder, resulting in the inability to drive the piston action of the brake.
5) Brake tubing rupture or oil leakage at tubing joints reduces the amount and pressure of brake fluid entering the brake cylinder.
6) Jammed afterburner piston or damaged sealing ring leads to decreased output of brake fluid oil and pressure.
7) Severe oil leakage in the caliper disc brake cylinder resulting in a significant loss of pressure oil prevents the piston action of the brake.
8) Jammed piston in the caliper disc brake cylinder causes immobility of the piston.
9) Brake friction pads contaminated with oil or excessive wear results in decreased friction coefficient or increased brake clearance, thereby reducing the braking force.
Fault Diagnosis and Troubleshooting:
1) Check the brake pressure and resolve any issues with low brake pressure. Ensure that the brake pressure is within the range of 0.45 to 0.70 Mpa.
2) If the brake pedal does not move despite normal air pressure when pressed, it indicates a stuck piston in the brake control valve. Disassemble the brake valves and repair or replace them.
3) If the brake pedal position is initially very low and gradually rises with continued pressure, but the braking effect is weak, it suggests the presence of air in the brake system. The air should be purged from the system.
4) If continuous pressing of the brake pedal feels heavy, but the pedal position gradually decreases, there may be an oil leakage in the brake system. The system should be checked and repaired. If required, the brake assembly should be disassembled for maintenance, involving the replacement of the rectangular seal ring or brake piston.
5)Despite purging the air from the oil pipe, the brake pedal remains feeble. Upon opening the refueling port cover, a turbulent movement of brake fluid is observed, indicating deformation or damage to the seal in the disc brake caliper. Affected components should be carefully examined and replaced accordingly.
6)The piston within the caliper disc brake cylinder is immobilized, requiring remediation for both the piston and associated sealing elements.
7)Upon the wear of the brake friction disc to 1/3 of its original thickness, it is imperative to replace the friction disc to avert potential harm to the brake disc.
8) When the brake disc is deeply grooved or seriously deformed, the brake disc should be repaired or replaced.
2.3 Brake failure
When operating the loader, if the brake pedal is pressed but the equipment fails to stop promptly and continues to slide.
Causes of failure:
1)Presence of air in the brake tubing or brake cylinder leads to oil pressure fluctuations or inadequate flow.
2)Excessive free travel in the brake pedal.
3)Severe wear on brake valve seals, afterburner seals, and brake cylinder seals, or extensive wear on the cylinder and piston causes air and oil leakage.
4)Blockage in the brake valve compensating orifice or air orifice.
5)Rupture of the brake tubing or oil leakage at tubing joints.
6)Excessive clearance between the brake disc and friction disc.
7)Surface hardening of the friction disc, rivet protrusion, or oil stains.
8)Poor quality of brake fluid, prone to heating and evaporation.
9)Depression or blockage in the brake pipe.
Fault Diagnosis and Troubleshooting:
1)Verify the brake pressure, rectify any issues related to low brake pressure, and ensure that the brake pressure value falls within the range of 0.45-0.70M.
2) If the brake pedal sinks significantly upon initial depression and gradually rises with continuous pressure, yet with insufficient braking force, it suggests the presence of air in the brake tubing or brake cylinder, which must be addressed.
3) Inadequate performance during one-foot braking is characterized by a gradual increase in pedal position and enhanced reaction force with continuous pressure, resulting in improved braking effectiveness. This indicates excessive free travel in the brake pedal or an excessive gap between the friction disc and brake disc. Begin by inspecting and adjusting the free travel of the brake pedal, followed by the adjustment of the gap between the friction disc and brake disc.
4) If continuous pressure on the brake pedal yields a heavy feeling accompanied by a gradual decrease in pedal position, it suggests an examination and repair of brake system oil leakage. If necessary, remove and maintain the brake, replacing the rectangular seal ring or brake piston.
5) If the brake pedal remains weak even after removing air from the oil pipe, and violent turning of brake fluid occurs when opening the oil filling cover, it signals deformity or damage to the seal in the nipper disc brake. Replace the damaged parts accordingly.
6) When the brake pedal exhibits a very low position upon initial depression and fails to rise with continuous pressure, it typically indicates blockage in the ventilation or compensation holes of the brake valve, which should be cleared.