How To Fix A Floor Jack That Won’t Lift? Step By Step Instructions

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A secure and straightforward assistant in lifting heavy loads has a reliable design, which serves as a guarantee of safe operation. A high strength criterion is considered to be the primary indicator of the effectiveness of the floor jack.

However, even this level does not exclude the possibility of damage to the device. In this article, we have brought all possible causes of failures of floor jacks and took them apart and made step-by-step instructions to resolve those or other faults.

Pay attention! Mechanical damage of both the body and the piston of car jacks is not considered. In case such breakage repair of floor jacks will be inexpedient — it is better to buy the new device.

In other cases, it is necessary to disassemble the mechanism and assemble it back so that the conditions are met:

  1. Valves fit snugly.
  2. Sufficient amount of working fluid in the departments.
  3. There’s no air in the system.

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Main Faults And Their Causes

The floor jack rarely breaks down seriously; most often, the problem is contamination, valves, or lack of fluid. All this is easy to repair, as well as to fix a rare problem — leakage.

Among all the reasons why the floor jack does not work, there are three main options: system clogging, valve failure, or stem damage. It is on these three whales that the most common breakdowns associated with a decrease in the efficiency or complete failure of the system are based. For greater clarity, let’s take a look at each case in more detail.

System Clogging

Clogging of the system can be caused by air, dust, or dirt entering the liquid. As a result of the first embodiment, the stop of the car jack may not rise, spring heavily or drop under load.

The accumulated clumps of dirt can restrict the movement of the valves, which will no longer close the channels tightly, passing the fluid in both directions.


In this case, the stop will not be fixed in one position, gradually descending to the zero level. When figuring out the circumstances why the hydraulic jack does not hold, first of all, you should pay attention to the cleanliness of the system.

Also, with the constant operation of the device, air accumulation is inevitable.

The floor jack works on the principle of communicating vessels, that is, when the fluid leaves, the pressure remains. But the air in the system does not escape under pressure, but is deformed and creates a pillow, due to which lifting is impossible.

The air is removed when changing the oil. Dirt is removed with a solution to remove deposits.

Valve Failure

Valve failure, in addition to mud blockage, can be caused by mechanical damage. The ball at the end of the spring, resting on a cone-shaped groove, can detach or catch on other structural elements.

In this case, the stem will not rise at all, because the fluid circulation in the system is broken, and pumping is not performed.


This breakdown is more complex and requires disassembling the device. It is not recommended to consider it before checking the system for blockages.

On a note. If the jack is full but still does not hold or lift the load, it is necessary to disassemble the device and check the valves.

Attention is drawn to how the valves are adjacent to the seats. If the contact is loose, the springs that may have loosened are checked. Valves could become clogged, so you need to remove dirt using a damp cloth, then dry thoroughly.

If the pollution is severe, for example, due to oil, then rinse with gasoline, kerosene. Then dry with compressed air.

If the valves are deformed, they must be replaced with new ones.

Springs are checked, in case of loosening they are replaced by more elastic. If it is not possible to replace, then a washer can be placed under them so as to increase the density and strength.

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Stock Damage

Damage to the stock can occur due to non-compliance with the conditions of service or storage, as well as from working with large loads and violation of the operating rules.

In the first case, the piston can be covered with corrosion, which will reduce the density of its adhesion to the cylinder, in consequence of which the liquid will seep. If you lift loads more massive than the permissible limit, the stop may bend.


The chances of such a failure are increased with the maximum extension of the screw and uneven installation of the auto jack on the ground. Deformation of the stock is considered the most severe failure, which is not always subject to repair, even in specialized centers.

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How To Fix A Floor Jack That Won’t Lift?

One of the common problems that arise in the operation of floor jacks is the reduction of the speed of the stem extension to a minimum or even to zero. This failure is often associated with a decrease in the height of the lift and a decrease in the maximum load.

The main reason for this failure lies in the airing of the system due to a drop in oil level. Restore the efficiency of the device, in this case, is not difficult. This will require a little oil (150-300 ml) and washing fluid (if the tool is more than two years old).

  1. First of all, turn the shut-off valve one turn from the tightened position. Then lower the pump piston and the stop to the zero level.
  2. Unscrew or remove (if rubber) plug on the filler hole and drain the old oil in any container
  3. If the device is several years old, its internal channels could likely be clogged with dirt, which can be no less a good reason why the floor jack won’t lift. It is recommended to rinse the device, and preferably several times. To do this, you can use kerosene or gasoline. Just pour the fluid through the hole from where the oil was poured, close the valve, raise the stop by pumping the pump, open the lid, lower the stop, and repeat the process two times. Then drain the dirty liquid, pour a new portion of clean one, and do the above actions at least one time (see the purity of the drained composition).
  4. When there is confidence in the purity of the system, you can fill it with oil. Here you can use almost all varieties, except brake fluid. The main thing that the consistency was not too thick. It is desirable to use a specialized hydraulic or synthetic industrial.
  5. Before pouring the oil, lower the pump piston and stop to zero position and tighten the valve. If the jack is a bottle, while pouring it should be installed in the vertical, operating position (the rolling low profile floor jack is refueling in horizontal).
  6. It is most convenient to fill the car jack through a syringe, smoothly filling the liquid consistency until it fills the entire volume of the tank and begins to flow out of the hole.
  7. Upon completion of refueling, it is necessary to pump the system, expelling excess air from it. To do this, with an open filler hole, pump the oil from the reservoir into the cylinder. When the stop reaches its maximum height, unscrew the shut-off valve and lower it. Perform the procedure 2-3 times.
  8. There is another method of pumping, without the use of a pump, if the previous one did not give results. It is necessary to unscrew the shut-off valve by 1-2 turns, then pull out and immerse the rod into the cylinder by hand, each time reducing the lifting height by 1 cm until you reach the zero mark.

The sequence of these simple actions will take no more than 20 minutes, and is likely to restore the effectiveness of your floor jack.

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Operating Recommendations

After use, the jack must be unloaded. Store the device in a warm and dry place. Due to the ingress of excess moisture, the mechanism can rust, and the cold will adversely affect the quality of the oil. It is recommended not to work with the jack in extreme cold.

The load on the device must not exceed those for which it is designed.

It is necessary to monitor the quality of the working fluid — in some workshops refined, or low-quality industrial oil can be poured. This will lead to quick breakage and contamination of the floor jack.