The brake system is an indispensable part of the forklift to control deceleration and parking and ensure personal safety during driving and operation. Therefore, faults should be handled and eliminated to make the forklift good use effect. The following are several faults and judgment methods of forklift braking system.

When the forklift is in operation and driving, the brake fails suddenly. Multiple feet are pressed to the bottom is invalid, or the brake pedal is weak, different from the normal operation function.

Cause analysis:
1 There is no brake fluid in the master cylinder or too little brake fluid to maintain the brake work, resulting in brake failure.

2. The master cylinder cup is ageing, damaged or overturned, and the pushing function cannot control the brake fluid.

3. The wheel cylinder cup is aged, damaged or trampled over.

4. The brake oil pipe is seriously cracked, the joint is disconnected, and oil leakage occurs so that the brake fluid does not enter other working ranges.

Diagnostic measures:

In brake failure during forklift operation, stop the forklift immediately for an inspection. First, observe whether there is leakage of brake fluid. For example, the dust boot of the brake master cylinder pushrod is damaged. If a large amount of brake fluid flows out from the edge of a wheel brake drum, it indicates that the wheel cylinder cup is overturned or seriously damaged. The leakage of brake fluid in the brake pipeline is generally apparent. If there is no brake fluid leakage or little brake fluid, it is required to supplement it in time.

Poor braking effect:

When the forklift uses the brake during driving, the braking distance is long, and the speed of the forklift cannot be slowed down or stopped at any time. Sometimes it breaks several feet continuously, but the braking effect is not good.

1. The master cylinder is faulty.

2. The wheel cylinder is faulty.

3. The brake is faulty.

4. Air enters the brake pipeline

Inspection and diagnosis:

1. Generally, it can be judged according to the brake pedal travel (high and low) or the soft and rugged feeling of pedal braking. The brake pedal height is too low, and the braking effect is not good. If your brake several consecutive times, the height of the pedal increases and the braking effect can improve. It indicates that the clearance between the brake drum and the friction pad or between the master cylinder and the pushrod is too large

2. If the pedal is on the brake pedal and the height of the pedal decreases slowly or rapidly, it indicates that the brake pipeline is broken somewhere. If the joint or the cylinder cup is not tightly sealed, there is oil leakage, the return spring is too soft or broken, or the master cylinder cup and ring are poorly sealed. Observe no brake fluid (oil) leakage through the test, and disassemble and inspect the wheel cylinder and master cylinder.

3. After several continuous brake tests, the pedal height is still too low. After stepping on the second brake, the master cylinder cup is broken, or the return spring is too soft.
4. After a few feet, press the pedal to the bottom and feel no reaction force on the pedal, indicating a severe loss of brake fluid in the master cylinder oil container.

5. Several brake pedals are slightly higher and elastic, indicating air infiltration in the brake pipeline.

6. Several foot brakes, the pedal height is low and soft, and the vent hole of the plugin the reservoir in the oil inlet hole of the master cylinder is blocked.

7. When braking with several feet, the pedal height is appropriate but too hard, and the braking effect is not good. Check whether the clearance between the friction plate and drum of each wheel is standard. If the clearance is average, check the surface condition of the drum wall and friction pad. If it is normal, check whether the brake shoe spring is too hard, whether the leather cup of the master cylinder or wheel cylinder expands, and whether the fit between piston and cylinder wall is loose

Brake deviation:

The forklift tilts to one side and mops the ground using the brake. There are friction marks between the tire and the ground, but there are no marks on the other side; The car cannot be braked, or the drag mark is short; The drag marks on both sides are short, and the wheel brakes on both sides are inconsistent.

Cause analysis

1. The contact area of the friction between the two front wheels is too different, the quality of the friction plates of the two front wheels is different, the elastic force of the return spring of the brake shoes of the two front wheels is different, the clearance between the brake drum and the friction plate of the two front wheels is different, and the inner diameter of the brake drum of the two front wheels is too different, which are easy to cause uneven stress and affect the quality of braking

2. The wheel cylinder piston on one side of the front wheel has excessive friction with the cylinder barrel and is too ageing. The front-wheel cylinder has aired on one side, the hose is ageing, the cylinder cup is poor, or the brake drum on one side of the front wheel is out of round. The air pressure of the two front tires is inconsistent, the front wheel friction pad on one side has oil stain, water moisture hardening, and the rivet is exposed, which will affect the quality of the brake pad.

3. The supporting pins of two front wheel brake shoes are eccentric, and the degree of friction is different

Diagnostic processing:

Test the empty forklift on a flat road to check the friction drag marks between the tire and the ground. If the drag marks are short or not, it means that the braking effect of the wheel is not good or there is no braking at all. Check whether there is oil leakage, whether the oil pipe joint is good, whether the oil pipe is broken, whether the tire pressure is sufficient and whether the tire pressure on both sides is consistent. Check the clearance between the friction plate and the brake drum and whether the wheel cylinder has penetrated the air if all are normal. If there is no air infiltration, remove the brake drum and check each component item by item.

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