What to do about oil leakage of forklift cylinder?

Hey, dear friends! Today I will share with you an analysis of the steps of oil cylinder failure in forklift maintenance. If you are a smart little expert interested in forklift maintenance, or are experiencing the torture of forklift oil cylinder failure, then you have come to the right place! The following content will take you into the magical world of forklift maintenance and help you solve this troubling problem. Forklift oil leakage has always been the most common problem that troubles customers. Whether it is internal combustion forklifts, electric transport trucks and electric stackers, or manual transport trucks and manual stackers, there is a problem of oil leakage. It seems that the oil leakage problem is a problem that cannot be solved for a long time, and it has been troubling companies and customers. However, today we will analyze which places are prone to oil leakage, why oil leakage occurs, and how to deal with it.

Finding the problem

During use, if you find that the forklift is unstable, slows down, or makes unusual noises during lifting, it is likely that there is a problem with the cylinder. In addition, if you observe hydraulic fluid leakage, foam or bubbles, or obvious damage to the cylinder piston rod, it is also a clear sign. Remember, the sooner you find the problem, the faster you can solve it!

Troubleshooting

Once you find signs of cylinder failure, we need to troubleshoot the problem. First, check whether the cylinder connection is loose or leaking, and check the condition of the hydraulic fluid and whether there is obvious damage on the surface of the cylinder piston rod. If any problems are found, take timely measures to repair them. In addition, check whether the pressure of the hydraulic system is normal to ensure that the system is working within the normal range.

Failure and causes of lifting cylinder:

The piston rod of the lifting cylinder automatically descends, and the piston rods of the two lifting cylinders are not lifted synchronously.

The reason is that the piston seal is not sealed, and the two chambers of the cylinder are in contact with each other, resulting in a drop in pressure; the hydraulic oil leaks out during the lifting of the piston rod of the lifting cylinder, which is caused by the seal and dust ring in the piston and cylinder cover not being sealed; the piston rod of the lifting cylinder shakes when it is lifted, one is that there is air in the pipeline to the piston section of the cylinder; the other is that there is less hydraulic oil in the system, resulting in insufficient oil pump pressure.

Failure and causes of tilting cylinder:

The piston rod of the tilting cylinder automatically extends (that is, the mast automatically tilts forward), and the tilting cylinder shakes when the piston rod acts on the mast to tilt backward.

The reason is that the piston seal is not sealed, or there is less hydraulic oil in the system; the hydraulic oil leaks out when the piston rod of the tilting cylinder extends, because the seal and dust ring in the guide sleeve are not sealed.

Solution

Once you have identified the cylinder failure and completed the troubleshooting, the next step is to choose a solution. Depending on the specific situation, you can choose to rebuild the cylinder, replace the seal, repair the piston rod, or replace the entire cylinder unit. Choose the solution that best suits your forklift and make sure to choose high-quality parts and the right tools to effectively solve the problem and prevent it from happening again.

Oil cylinder leakage

1.Internal leakage

(1) The wear gap between the valve stem and the valve body is too large

The long-term use of the distribution valve or unclean oil accelerates the wear of the valve stem and the valve body, destroys the matching sealing surface, and causes oil leakage. If the valve stem is lightly worn during repair, the valve stem can be chrome-plated and polished; if the valve stem is severely worn, it needs to be replaced

(2) Oil leakage between valve bodies

The sealing ring fails, resulting in internal leakage; during installation, the valve body is damaged or the O-ring is aged or damaged. Under the action of oil pressure, internal leakage is also likely to occur between the valve bodies.

If the valve body is damaged, it is necessary to grind and replace the O-ring, and tighten the bolts according to the sequence and torque requirements.

(3) Safety valve spring failure

If the safety valve spring fails, the hydraulic oil can force the steel ball to leave the valve position and flow into the overflow channel at a pressure lower than the specified system pressure, causing internal leakage and making the system fail

(4) The multi-way reversing valve stem cannot be reset

If the valve stem cannot be reset, the groove is connected to the oil channel, which will cause internal leakage.

One is that the valve stem reset spring is deformed or damaged, the spring force is reduced and the valve stem cannot return to its original position. The spring must be replaced during repair;

The second is that the valve body and the valve stem are not clean, which produces a large resistance, making it difficult to reset the valve stem. During repair, the inside of the multi-way reversing valve must be cleaned to eliminate the resistance.

(5) Cone valve wear

The cone valve is used to prevent oil backflow. If the cone valve is worn and the oil channel is not tightly closed, the hydraulic oil will flow back and the system will fail. During repair, it should be ground or replaced to eliminate backflow.

2.Oil leakage from valve body

The seal between valve stem and valve body is realized by O-ring. If the seal is aged or damaged, the hydraulic oil will flow out along the valve stem under the pressure of the system, causing oil leakage from the valve body. To eliminate this fault, just replace the O-ring.

Analysis of the steps for repairing the oil cylinder failure of a manual forklift

1. If the manual forklift is in use, the pressure is automatically relieved after loading the goods, and the fork cannot be lifted; or there is oil leakage in the oil cylinder; the fork cannot be lifted at all, etc., it means that there is a problem with the oil cylinder.

2. The steps for repairing the oil cylinder failure of a manual forklift are mainly to check the seal ring and piston rod of the oil cylinder.

3. There are three seal rings in the oil cylinder of the manual forklift, two sets of seal rings are set at the contact part between the piston rod and the oil cylinder; there is a set of seal rings at the bottom of the cylinder body; there is a set of seal rings at the oil filling port

4. When replacing the seal ring, you need to use a circlip pliers to remove the seal ring from the oil cylinder first, and select the seal ring of the same size according to the model on the seal ring to truly achieve a good sealing effect.

5. At the same time, when replacing the hydraulic oil in the winter in the north, replace the low-temperature hydraulic oil to prevent the hydraulic oil from solidifying and causing poor up and down movement, which will also cause the phenomenon of difficulty in lifting.

6. Another kind of fault is not very common, that is, in the steps of repairing the hydraulic cylinder of the manual forklift, there will be a situation where the manual forklift does not like to descend. In addition to the deformation of the fork legs or the deformation of the casters and bearings, it may also be due to the deformation of the piston rod of the hydraulic cylinder.

7. Check the spring of the control valve. If it rises when the handle is pressed and falls when the handle is lifted, the control valve spring should be checked.

I hope that through this article, you can learn how to analyze the forklift cylinder failure and the solution. Whether you are a novice maintenance worker or a user who wants to solve the forklift failure, you can gain knowledge and skills from this article. Remember, early detection of problems, accurate troubleshooting and selection of the correct solution are the key to keeping the forklift running normally!

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