During the daily use of hydraulic jacks, various problems may occur. Today, TorcStark will introduce you to how to maintain hydraulic jacks with a few questions.

Small details you need to pay attention to when changing the hydraulic oil of a hydraulic cylinder.

Hydraulic oil is the key to the power source of hydraulic jacks. The operation of hydraulic jacks relies on Pascal’s Law, and its pressure is generated by the transmission of hydraulic oil. At the same time, the smoothness of power transmission is closely related to the purity of hydraulic oil.

After the hydraulic jack is used for a long time, the quality of the hydraulic oil will inevitably change under the influence of the surrounding environment and temperature. Therefore, replacing the hydraulic oil is an important part of ensuring the good performance of the hydraulic jack for a long time. Many people do not know how to replace hydraulic oil in hydraulic jacks, which leads to a sharp drop in the performance of hydraulic jacks. Now, TorcStark will briefly introduce the correct way to replace hydraulic oil.

Generally, the oil filling port of the hydraulic jack is on the side of it. We need to find the rubber plug of the oil filling port and pull it out, then put the hydraulic jack upright so that the filler port is facing up, and then slowly pour the hydraulic oil into the filler port. After filling up the oil, push the piston rod tightly, and then tighten the rubber plug again.

There are a few small details to pay attention to when refueling:

First: clean the old oil inside first, and then replace it with new oil.

Second: in the process of pouring oil, in order to prevent the hydraulic oil from spilling, a funnel can be used.

Third: add a layer of filter screen when pouring oil to filter out some tiny impurities in the hydraulic oil, so that the purity of the hydraulic oil can be higher.

Fourth: The hydraulic oil does not need to be overfilled. Generally, the height can be equal to the horizontal position of the oil port.

How does the damage to the seal affect the hydraulic jack?

Most of the mechanical equipment containing fluid requires sealing rings to seal to ensure the normal operation of the mechanical equipment. This design of sealing with a sealing ring is the most typical in hydraulic equipment, especially on hydraulic jacks, from which we can see the importance of sealing for hydraulic jacks.

So when the hydraulic jack seal is damaged, what will happen to the hydraulic jack?

Here are some instructions from TorcStark.

After the sealing ring of the hydraulic jack is damaged, its airtightness will naturally be seriously affected. Since the sealing ring is generally placed around the lifting sleeve, the hydraulic oil in the hydraulic system will not be 100% bound by the sealing ring. Under huge pressure, the hydraulic oil will leak along the gap around the sleeve.

When the hydraulic oil leaks, the entire closed hydraulic oil circulation of the hydraulic jack is no longer transmitted according to the normal route, resulting in a huge change in the internal pressure. As the number of uses increases, the hydraulic oil will become less and less, which will eventually lead to the loss of the rated load of the hydraulic jack.

It can be seen how serious the consequences will be if the hydraulic jack does not have good sealing. Therefore, in order to ensure the sealing of the hydraulic jack, we must always pay attention to whether there is any leakage of hydraulic oil around the sleeve.

Why does the return speed of the hydraulic jack slow down?

The advantage of hydraulic jacks is that the operation is simple and labor-saving and efficient. Its high efficiency is mainly reflected in one point, that is, the hydraulic transmission speed is fast, which ensures that the hydraulic jack has the incomparable advantages of general mechanical jacks whether it is lifting or returning.

Of course, after a long period of use, the hydraulic jack is not as smooth as it used to be. With the increase of use time and frequency, some small problems will also occur in the hydraulic jack, such as the slow return speed of the jack, which is common and will naturally affect the work efficiency.

So what causes this?

TorcStark is here to answer this question for you.

The slow return of the hydraulic jack may be caused by the following reasons:

First, the state of hydraulic oil has changed under special circumstances. For example, the viscosity of the hydraulic oil increases in extremely cold weather, which leads to a decrease in the fluidity of the hydraulic oil, which naturally leads to the failure of the entire hydraulic system. The transmission is slow, and the return speed of the hydraulic jack is also reduced.

Second, there is a problem with the sealing ring of the hydraulic jack. Once the sealing ring is defective, it will cause the hydraulic jack to leak internally or externally. The leakage of hydraulic oil will naturally seriously affect the transmission of the hydraulic system. The return speed will decrease.

Third, the return stroke of the hydraulic jack is by twisting the pressure relief valve, so that all the hydraulic oil in the main oil tank flows back to the oil storage tank. If the pressure relief valve is not fully opened, or there is a blockage of impurities, the hydraulic oil will not flow back smoothly to the oil storage tank through the oil circuit.

Any of these three points will seriously affect the return speed of the hydraulic cylinder.

Precautions when using hydraulic jacks

1. When using it, the place where it is placed should be flat and tough. Oil-free planks can be used to expand the bearing surface and ensure safety. Do not use iron plate instead of plank to prevent sliding.

2. It is required to be stable when lifting. After the heavy object is lifted a little, check whether there is any abnormality. Continue to lift only if there is no abnormality. Do not lengthen the handle arbitrarily or operate it too hard.

3. Do not overload or exceed the height limit. When a red line appears on the sleeve, it indicates that the rated height has been reached and the jacking should be stopped.

4. When several units are working at the same time, there must be a special person to command, so that the lifting or lowering can be carried out synchronously. The two adjacent hydraulic jacks should be spaced by wooden blocks to ensure the spacing and prevent sliding.

5. When using, always pay attention to the sealing part and the pipe joint part, and it must be safe and reliable.

6. Not suitable for places with acid, alkali, or corrosive gas.


The above are some common problems and maintenance methods for hydraulic jacks. In daily use, the user should always pay attention to the state of the hydraulic jack and solve the problem in time. Never use it in a bad state, or it will eventually damage the tool, affect the quality of the project, and even cause personal danger.