Troubleshooting methods for the braking system of loaders

With the rapid development of highway engineering construction and the gradual improvement of the mechanization level of maintenance, more and more construction units and individuals who rent out have purchased various earthmoving machinery, among which loaders are the most common. A correct understanding of the structural features of the braking systems of these devices and mastering the troubleshooting methods for common faults can ensure the normal operation of the equipment. Here, taking the caliper disc brake system widely used in wheeled construction machinery as an example, the common fault phenomena and their elimination methods are illustrated.

1. The pressure on the barometer rises slowly

The main reasons are: (a) Gas leakage in the pipeline; (b) The air pump is not working properly; (c) Rust and jamming of the check valve; (d) The oil drain bolt of the oil-water separator is not tightened or the pressure regulating valve is leaking.

Troubleshooting method: First, eliminate air leakage in the pipeline, and then check the working condition of the air pump. Remove the exhaust pipe of the air pump and press the exhaust port with your thumb. If the exhaust pressure is low, it indicates that there is a problem with the air pump. If the air pump is in good working condition, then check the oil drain plug of the oil-water separator or the pressure regulating valve to avoid bypass and eliminate faults through inspection. Finally, check the two check valves in the three-way joint. If the check valves are stuck, it will cause the air storage cylinder to fail to intake air or intake air slowly.

2. Insufficient braking force, weak

The main reasons are: (a) Oil leakage from the brake; (b) There is air in the brake oil circuit; (c) The hub oil seal is damaged and there is oil stain on the caliper plate. (d) Severe wear of the brake and burning of the friction surface; (e) The air pressure in the airway is adjusted too low.

The above-mentioned faults can be eliminated by repairing, adjusting or replacing parts according to their respective causes.

3. Deviation after braking

The direct cause of deviation is the unequal braking torque of the wheels on both sides. Common fault causes: (a) Severe oil stains on the brake caliper disc, a significant decline in the friction system, resulting in unbalanced braking torque. At this time, the oil stains on the brake caliper disc should be removed. (b) The piston of the sub-pump is stuck and cannot work. When the vehicle is stationary, step on the brake, observe the operation of the slave cylinder, and disassemble and inspect it as needed.

4. Brake caliper

Fault phenomenon: The loader has difficulty starting and moving. After stopping, when touching the caliper plate by hand, the caliper plate gets hot. The main reasons are: (a) The friction plates wear out and become thinner, the dust-proof ring is damaged and water enters, and the piston rusts and gets stuck. (b) The reset spring in the booster pump is weak or broken, and the high-pressure oil cannot be added.

5. Fault phenomenon

When the brake is applied, oil mist is sprayed out. Cause: (a) The brake light switch is damaged, and high-pressure oil spurts out from the switch interface. Replacing the switch can solve the problem. (b) The length of the piston rod of the booster pump is too large. This situation may occur when a new booster pump assembly is replaced. The reason is that the piston rod is adjusted too long, causing the piston stroke to be too large when the booster pump is working, and the brake fluid to flow back into the booster pump through the oil drain hole and spray out. When installing, the working stroke of the piston should be measured to determine the length of the piston rod.