How to bleed a hydraulic jack

How to bleed a hydraulic jack, and other questions about lift maintenance

Man has invented many devices for lifting weights. To briefly describe the principle of their operation - the transformation of the distance traveled into effort.

Let's look at examples of such transformations:

Lever arm. On the long side, the distance traveled is greater and the effort is less. On the short side it's the opposite;
Block system. The cable, passing through a certain number of blocks, loses distance with each loop, proportionally acquiring additional traction force;
Gears with different gear ratios. The small gear rotates quickly and with less force. Big – on the contrary;
Chain (belt) pair. A smaller diameter pulley rotates effortlessly and faster. A larger diameter pulley develops high torque on the shaft at a lower rotation speed;
Communicating vessels. Two piston pairs connected to each other operate on the principle of a lever. A piston of a smaller diameter moves with a small force with a large swing. While its larger “brother” moves a short distance with proportionally increased effort.

A hydraulic jack operates on the principle of communicating vessels.

Relatively compact dimensions (compared to the force that the tool can develop) make it indispensable when working with large weights. Portable bottle jacks (this is their second name) develop a force from 1 to 20 tons. Larger specimens can weigh up to 200 tons.

At the same time, hydraulics are among the safest devices for lifting heavy objects.

Design, features of using a bottle jack

The illustration shows what components a hydraulic lift consists of.

The entire structure fits inside a reservoir with working fluid. The lifting rod in the lower position is completely recessed into the housing. The lever handle is removable and does not take up much space in the transport position. Therefore, jacks of this type easily fit in the trunk of a car.

The device, capable of lifting a solid SUV (force 5 tons), has dimensions (taking into account the detached handle) no larger than a 0.7 liter bottle of wine. One person can handle such a jack.

Advantages:

Easy to operate and maintain;
High efficiency – up to 80%;
Low force on the working handle;
Smooth operation due to the use of liquid;
Ability to control lift height with high accuracy;
High reliability due to the absence of rotating and rubbing parts;
Long service life - other than the O-rings, there is nothing to wear out in the bottle jack;
A good indicator of safety in operation - in the event of a breakdown, a sharp fall of the lifted object or a part of the tool being thrown to the side is excluded;
Wide range of application possibilities, not limited to use only in cars.

Flaws:

The height of the jack body is almost equal to the lifting height. This is typical for single-rod designs; telescopic (multi-rod) options do not have this drawback. This feature is partially compensated by a screw that unscrews from the rod - an extension. Due to this disadvantage, the initial lifting height starts from 20-25 cm. This limits the dimensions of the device;
Slowness. One cycle of operation of the injection pump provides lifting to a low height. The higher the load capacity, the more movements the handle must be made to lift;
Inability to accurately control the height of the load;
Work only in a vertical position. In an inclined or horizontal state, air will enter the hydraulic system and it will have to be pumped;
Large mass of the device, taking into account the working fluid;
High cost of the product.

To work with low initial heights (for example, low-slung passenger cars), a rolling jack is used. It operates on a lever circuit, and a hydraulic cylinder is used as the driving force, as in a conventional bottle jack.

DIY hydraulic jack maintenance and repair

To know how to repair this device, you need to study its structure and operating principle. The cross-sectional diagram is shown in the figure:

The working cylinder (4) is tightly screwed into the powerful base (10).

The connection must be reliable, since the pressure of the working fluid (6) when lifting heavy objects is quite high.

A working piston (5) with a sealing ring is placed in the cylinder. An extension screw (3) is screwed into the working piston (also known as the lifting rod), which, if necessary, is unscrewed by 2/3 of the length of the rod.

The screw ends with a support platform (7), which has anti-slip corrugation.

Around the working cylinder there is a protective casing (2), which serves as a container for the working fluid (6).

Nearby there is a pressure cylinder (plunger) (8), hermetically screwed into the base.

It is equipped with two valves. The intake valve, when the pressure piston moves upward (9), fills the cylinder with working fluid.

When the injection piston is lowered, the liquid enters the working cylinder through the supply valve and presses from below on the working piston (5).

Under pressure, the rod moves upward, lifting the load. The cycle is then repeated until the required lift height is reached.

At the end of the work, the bypass valve (1) opens, and the liquid from the working cylinder (4) flows into the container body (2).

The valve has a ball valve that can withstand high pressure. The working piston lowers under the weight of the load, displacing all the liquid into the container.

The jack is ready for the next lifting cycle.

Repair and service

The jack must be disassembled for maintenance. You should not be afraid of this; there is no high pressure in it.

First you need to drain the hydraulic oil. This can be done through the filler plug, or, if it is missing, through the bypass valve. To do this, unscrew the upper hex nut and completely unscrew the lower valve.

Then the housing is removed, the tightness and condition of the lower rubber ring is checked.
This element does not carry a large load; it simply prevents liquid from leaking out of the housing. We unscrew the working cylinder from the base and remove the piston.

We check the condition of the inner surface of the cylinder and the piston sealing ring. If there is corrosion (which is unlikely), the surface of the cylinder is ground and polished.

We unscrew and check the condition of the plunger (discharge piston) and its sealing rings. We check the axles, rod and lever body. There should be no dents, cracks or wear out of metal. Damaged rubber seals must be replaced with new ones.

We wash all valves to remove possible deposits and debris. We assemble the jack to its original position.

How to fill the oil?

Hydraulic fluid is poured through the neck located on the side of the housing. It is also a level. There is no load on the plug, there is no pressure inside the body. Then the hydraulic jack needs to be pumped. This is a simple but responsible procedure.

After pouring, it is necessary to raise the rod to its maximum height (without load). Then the jack is placed horizontally, with the filler plug facing up. The plug is loosened and the rod is vigorously pressed into the cylinder. Most of the air will be squeezed out into the container with liquid.

Then the plug is tightly closed, and several (up to 20) full cycles of lifting to the maximum height with a load of 30-50 kg and lowering the rod are performed. After which you should perform a control lift under an increased (100-500 kg) load. If the jack does not “hold” the load, repeat pumping.

What oil should I fill? The one indicated in the product passport or in the instructions. If the documents are lost, find information on the manufacturer’s website. Experienced professionals advise using the so-called. spindle. This is only true for older models.

Still have questions? Watch a video about repairing a 12-ton hydraulic bottle jack.

Source: http://obinstrumente.ru/ruchnoj-instrument/kak-prokachat-gidravlicheskij-domkrat.html

Jack repair, how to bleed a hydraulic jack

instrument.guru > Auto tools > Jack repair, how to bleed a hydraulic jack

It takes a lot of force to lift the load. To solve such problems, a jack is designed - a simple mechanism that is widely used in industry and is indispensable in everyday life. To lift a relatively small load, manual strength or a simple mechanical device is sufficient.

Hydraulic jacks are used to lift heavy loads. In such devices, the force is created using a special piston and hydraulic oil.

For reliable and trouble-free operation, periodic maintenance is required: cleaning the tank, replacing hydraulic fluid, bleeding equipment.

Design and principle of operation of a hydraulic jack

The main element of a hydraulic jack is the body. It is made from high-strength steel grades. It has two main functions: it serves as a guide cylinder and is a container for working fluid, which is used as hydraulic oil.

The second component included in the lift is the movable piston. The jack is also equipped with a hydraulic pump, which, due to the pressure created, raises a special platform.

Additional elements that operate the lifting device are the plunger, lever and valves.

The principle of operation is based on the movement of working fluid from a common container to the one located under the piston. Pumping is carried out using a plunger, and the valve prevents the liquid from moving back. If you open the valve slightly, the oil will return to the common container and the rod of the device will lower.

Types of hydraulic jacks

For different fields of activity, different types of lifting devices were created, which were distinguished by their ease of use for certain and specific types of work. Hydraulic jacks are divided into the following types:

bottle type is the most common type. Such devices of various modifications lift loads from 2 to hundreds of tons. They are very popular among drivers and are used in almost all areas of the economy. Structurally, bottle jacks are divided into single-rod and double-rod. Single-rod ones can only work in a vertical position, double-rod ones - in any direction;
rolling - rolls under the load during operation. It got its name because of its resemblance to a cart. Control is carried out using a lever, which rotates to regulate the oil valve. Disadvantage - can only work on a flat and hard surface;
hook - designed for lifting low-profile loads from a small height (for example, a railway rail);
hybrid and diamond - used mainly by car services. These are various combinations of bottle and rolling jacks.

Causes of malfunctions

When jacks are used intensively, the main causes of malfunctions are heavy overload during lifting or hydraulic failure. When overloaded, the thrust rod usually bends.

As a result, the rod cannot pass through the coupling and becomes jammed in it. Repair of this type of fault is replacement of the deformed rod. It is impossible to straighten it yourself, since it is made of a special high-strength steel.

Hydraulic failure mainly occurs for two reasons:

For normal operation, it should only be used in a vertical position (this applies to storage and transportation). Due to improper operation, the engine oil contained in it leaks out, and air penetrates into the system. Using the jack with air slows down the operation of the device. Over time, he stops lifting the load altogether;
The internal parts of the hydraulic system are subject to rust, which leads to inhibition of the free movement of the system. The gaskets or balls in the valves wear out, and this disrupts the movement of oil in the device.

Repair and pumping

To do this, you need to unscrew the top hex nut and completely unscrew the bottom tap. After removing the housing, it is necessary to check the condition of the lower sealing ring, which prevents oil from leaking out of the device housing.

After this, unscrew the working cylinder and remove the piston from the base. Then we check the condition of the cylinder walls and the piston sealing ring. If the cylinder walls are covered with rust, they must be sanded and polished.

Now you need to check the condition of the injection piston (plunger) and its o-rings. The axles, rod and lever body must be checked. They should not have cracks, dents, etc. All valves need to be washed and the device can be assembled. Before filling the working fluid, it is necessary to flush the hydraulic channels with flushing fluid.

It is poured through the filling hole on the side of the housing, filling the oil reservoir with liquid up to the neck. Using a lever, pumping is done to release air. When flushing begins to flow into the oil container, all air has been removed from the system. It is advisable to rinse the jack 2 times, after which the liquid is completely pumped out.

You can add new oil. It is better to find out the brand from the manufacturer. Having previously completely lowered the rod, we fill it, and since the oil flows through the system, it is necessary to periodically top up. When pumping, we ensure that there are no air bubbles in the filler neck and tighten the plug. The jack is ready for further use.

Repairs, oil changes and maintenance of your lifting device can be done yourself. If you don't need spare parts, this job will be very cheap and enjoyable. The updated jack will serve for a long time.

Source: https://instrument.guru/avto/remont-domkrata-kak-prokachat-gidravlicheskij-domkrat.html

How to bleed a hydraulic jack

An indispensable device for lifting cars is a jack. It is included in new cars as mandatory repair equipment.

For passenger cars, a mechanical device is enough, but to lift trucks, you can’t do without hydraulics. Like any mechanism, the jack can fail, including due to intensive use.

To further work with it, it will be necessary to pump the working fluid. We will tell you how to bleed a hydraulic jack in our article.

Reasons for decreased efficiency

Before proceeding with repairs, it is necessary to diagnose the device. There may be several reasons why the device may not perform its functions. The main ones are:

airing of the working fluid (air bubbles appear in the oil, preventing the transmission of force to the piston);
corrosion plaque (reduction of passage channels due to the formation of corrosion layers on the stacks, reducing the diameter or clogging the oil passage);
loads that deform the working rod (a curved rod passes tightly in the working area and can transfer the load not along a given axis, which leads to the jack “shooting out” from under the lifted load);
contamination of the working fluid (oil contains particles of debris or metal wear, which negatively affects the quality of the device).

Disassembly and diagnostics

Standard do-it-yourself repair of a hydraulic jack begins with identifying defective places in the device and preliminary preparation for maintenance.

Types of hydraulic jacks

The work is carried out in several stages:

The fastening hardware is unscrewed.
The valve assembly is removed to relieve the pressure of the working fluid.
We take out the piston for inspection. The working side surface must be free of dents, nicks, ditches and obvious signs of wear. It has a smooth, even, polished surface. Otherwise, such roughness will cause poor performance of the jack.
Next, a visual inspection of gaskets, seals, and locking metal balls is carried out. If blocked channels are detected (fuse ball), then it is removed by loosening it; it is advisable not to use metal hammers so as not to damage the sockets. Gaskets and seals must be replaced if necessary.
If the working hydraulic cavities are contaminated, then the contaminated surfaces are washed to remove “grease.” Small channels can be cleaned using copper wire. It is not advisable to perform this operation with a steel rod or nail, as the surface is damaged and scratches and nicks are left.
The device is then assembled in the reverse order of disassembly. After this, clean oil is poured in and the jack is pumped. There should be enough oil to fully fill the device reservoir.

Source: http://ktonaavto.ru/avto-faq/raznoe/kak-prokachat-gidravlicheskij-domkrat.html

How to bleed a bottle-type hydraulic jack

Today it is impossible to imagine carrying out car repairs, be it replacing a wheel or repairing the suspension, without the use of jacks - special devices that are designed to lift a load and fix it at a certain height. And today the most popular are hydraulic jacks, in which force is created using a piston and working fluid.

Hydraulic jack device

The main elements in the design of a hydraulic jack are:

metal case;
hydraulic piston;
working fluid.

The hydraulic jack can have a regular or extended body made of hardened metal. The housing performs the following functions: it is a container for working oil and acts as a guide cylinder for the piston.

This type of unit is equipped with a hydraulic pump with air, foot or hand drive. The design of the jack contains safety valves and other devices to maintain trouble-free and long-term operation.

Retractable hydraulic cylinder and lifting mechanism . which raises a special platform, located in the holes of the housing. Lowering occurs by turning the T-shaped handle. The design has built-in wheels that provide mobility to the device. The elongated body of the shooting range is usually used to work with heavy vehicles and buses.

Principle of operation

Any hydraulic lifting mechanism works using fluid according to the principle of communicating vessels. Before work, you need to install the unit on a hard and level surface under the car and, with the valve closed, hold the lever until the car reaches the required height. The machine is lowered by opening the valve located on the jack body.

The operating hydraulic oil is pumped by the drive pump using a lever. The liquid moves into the cylinder through the valve, squeezing it out. The return of oil is prevented by two valves - suction and discharge. In order to lower the jack, you need to open the valve on the pump, in this case the liquid flows from the cylinder back into the housing.

The presence of threads on the body, protected by a special casing, threaded holes in the base and threads on the rod, guarantees unlimited operation of the jacks and the possibility of use for bending, clamping and crimping. A reliable support made of hardened metal and mounted on the rod protects the lifting mechanism from damage. The corrugated part of the base prevents the car from sliding.

Advantages and disadvantages

Hydraulic jacks are considered the most unpretentious . The main feature of hydraulics is the incompressible working fluid.

The result is smooth lifting of the load, precise braking and fixation at the required height.

Hydraulic jacks have excellent efficiency - up to 85% and a large load capacity - over 250 tons with little effort, thanks to the high gear ratio between the surfaces of the cylinder and the pump plunger.

https://www.youtube.com/watch?v=7bBd-1_rRjM

But with hydraulic lifting devices, the initial lifting height is much higher, unlike mechanical devices. Another difficulty is the inability to accurately adjust the lowering height.

To support the jack in the working position, you need to constantly monitor the tightness of the seals and valves, as well as monitor the oil level.

These units can only be stored and transported in a vertical position, otherwise liquid may spill out of the housing.

Disadvantages of hydraulic jacks:

They are quite slow.
They are large in size and weight.
High price.
Small stroke for single plunger jacks.

Bottle (vertical) jacks

The design of a hydraulic vertical jack is the simplest. The scope of use of these jacks is quite extensive due to the significant range of the load being lifted - from 3 to 200 tons.

Bottle jacks are used in trucks.

In addition to the main advantages of a hydraulic jack, bottle models have several more - a large support area, compactness and versatility of use.

Vertical jacks can be double-rod or single-rod. The single-rod device is characterized by ease of use and simplicity of design, which expands the scope of its use and makes it possible to perform work of varying complexity:

dismantling and installation in construction and mechanical engineering;
repair of carriage and car wheels;
use as a power unit of a pipe cutter, pipe bender, press and similar tool.

The two-rod telescopic jack has a similar design to the vertical one; the operating principle of the bottle mechanism is based on the installation of several rods. The piston is located at the base of the telescopic device.

It can be used in vertical and horizontal position. It fits most cars and has small dimensions. Lifting occurs using a lifting lever, which is brought into working position by a cylinder.

Rolling jacks

This type of jack works on the same principle as the vertical one, but with the difference that the cylinder is not in a vertical position, and the piston is not directly combined with the pick-up.

This device is called a rolling device because it is a cart on wheels that can be rolled along a surface.

When the lever is raised and picked up, the jack moves or “rolls” under the load .

This jack is set in motion, like bottle machines, by swinging the lever, and is also lowered by unscrewing the valve screw.

If it is necessary to lower the load, then you need to attach a tubular handle to the valve screw, then the partition fits into the groove of this screw.

By turning the handle around the axis, the operator also rotates the screw, thus reducing the pressure in the cylinder and lowering the car to the desired height.

As a rule, a rolling jack is used at a tire station, as it is ideal for lifting one side of a car and is quite quick to install and operate.

The disadvantages of this design come from the name - the rolling lifting mechanism requires a hard and flat surface, asphalt or concrete, to operate.

In addition, its heavy weight and size make it difficult to transport the device in a car.

Rolling jacks are divided according to their purpose:

For personal use of passenger cars with a carrying capacity of up to three tons.
For tire and automotive services, with a lifting capacity of up to four tons and with the installation of pre-lift levers to quickly achieve the required pick-up height.
For special vehicles and maintenance of heavy vehicles, with a lifting capacity of up to twenty tons and with the installation of pre-lift levers.

Hydraulic jack repair

Hydraulic lifting devices require periodic maintenance, which is why it is necessary to add oil to the working cylinder, which leaks out through various seals and oil seals during operation.

In addition to the question of how to bleed a hydraulic jack with your own hands, problems may also include jamming while lifting the car to the required height, as well as the inability to lift even a light load or the inability to release the piston after lifting.

Oil leak

To test or repair the jack yourself, you must purchase the required repair kit . Before repairs, you must first disassemble the unit. To do this, you may need an extension to the keys to get more leverage and significant force. Also, be sure to prepare containers for used oil and prepare new oil.

Then you need to remove the pistons and check them for corrosion. All corrosion and dirt must be removed. Check to see if the stem is bent. If deformation does occur, then it is unlikely that you will be able to level it again, so you can complete the repair with your own hands.

It is also worth checking the valve that transfers the oil. Why it is unscrewed and checked for dirt or deformation. If the valve is broken due to mechanical deformation, it simply needs to be replaced. In this case, it may simply become clogged, and the ball begins to sit loosely in its place. This is the reason for oil leakage.

Pour out the old fluid completely. This is a fairly simple procedure, although it will take you a lot of time while the liquid flows through the cylinders. The oil is drained by bleeding the system by moving the lever up and down. Wash all elements thoroughly to remove any remaining oil and dust. Completely replace all seals and seals .

Another reason for jack failure is dirt that gets into the working mechanism. To remove it, you need to unscrew the housing head, pour kerosene into the base and pump the jack with the locking needle unscrewed. At the end of the operation, the kerosene must be removed and new oil must be poured into the working part.

Entry of air bubbles

During prolonged use, air bubbles accumulate in the working part of the jack, significantly reducing its performance. Repair of this breakdown occurs in this way.

First, unscrew the bypass valve and the oil tank cap, and then quickly pump the pump several times . So, the air will escape from the working part into the oil tank.

After this, you can close the hole that leads to the oil tank and bypass valve. If everything is done correctly, the air will escape and the device will again operate as normal.

If the attempt is unsuccessful, repeat these steps.

So, you have become familiar with the design of a hydraulic jack, studied its advantages and disadvantages, understood the classification and know how to repair a hydraulic jack with your own hands. The main thing is to remember when operating it about periodic addition of working fluid and maintenance.

Source: http://sovetskyfilm.ru/all-1945/

Construction and repair of a bottle-type hydraulic jack

Devices that lift loads to a certain height have become indispensable in our time. A hydraulic bottle jack is a useful tool in construction, and especially in car repair.

Motorists cannot imagine car maintenance without this wonderful device.

If it happens that the jack fails, then you just need to know how to make repairs yourself.

Bottle jack device

As can be seen in the figure, the hydraulic bottle jack consists of the following parts:

Fig 1. Bottle jack design

1. Main piston

2. Lever

3.Stem

4. Suction valve

5. Shut-off valve

6. Oil storage tank.

7. Working chamber.

When a force is created on the lever (2), the rod (3) creates pressure, as a result of which the valve (5) opens, and the liquid flows into the working chamber (7).

When the lever is lifted up, the shut-off valve (5) closes and liquid is drawn into the pump cavity from the oil storage tank (6) by opening the pressure of the suction valve (4).

By pumping liquid from the reservoir (6) into the working chamber (7), the main piston (1) is raised.

The design of a bottle jack is quite simple; we pump liquid from one reservoir to another, and thereby build up pressure in the second, thereby raising the working piston.

Types, properties and characteristics of hydraulic bottle jack

Jacks are divided into several types, the first division is based on the number of rods (half-rams):

Single-stem bottle, the most common type Fig. 2.
Double stem bottle Fig 3.

Fig 2. Single-rod jackFig 3. Double-rod jack

There is also a division based on the operating principle of the pump pumping liquid:

Manual, activated by user pressure on the lever
Large pumps designed to lift enormous masses are driven by a separate drive, hydraulic pump or hydraulic station.

Properties:

Load capacity , an important parameter that determines the maximum lifted weight. The parameter depends on the volume of the working chamber and strength characteristics. Bottle-type devices have a load capacity from 2 to 100 tons.

Minimum lifting height , otherwise called minimum pick-up height. This is the height at which the load must already be in order to be able to place a jack under it.

Please pay attention to the minimum height if you are selecting a device for a car.

If you have low ground clearance, then a bottle-type device due to its high design will not suit you.

Maximum lift height. The height to which a load can be lifted. The bottle ones have a special feature: on the support platform there is a retractable screw that increases the minimum and maximum lifting height.

Why doesn't the bottle jack work?

There is little oil in the tank . The rod does not rise to the height specified in the technical documentation. To repair it yourself, we just need to add oil. Open the oil filler cap, fill it, then pump the jack, as described at the end of the article.

Oil is leaking . It happens that oil leaks in places, rubber bands and seals, this is the first sign that a major repair needs to be made, all gaskets and seals need to be replaced, and a flush must be carried out. To repair a hydraulic bottle jack yourself, you will need a repair kit.

It sags under load . Occurs due to the air inside; one of the rubber bands or gaskets allows oil to pass through and instead air enters the working chamber, which tends to compress strongly under load. To eliminate the problem, it is recommended to repair the jack, change all gaskets and fill in new oil.

Repair and service

Hydraulic bottle jacks

In order to service the bottle jack, it must be disassembled. There is no need to worry about being splashed with oil from high pressure. It is quite possible to do this operation yourself. The first step is to drain the oil.

Draining is done through the filler hole, and if there is no drainage through the bypass valve, to do this, unscrew the upper hex nut and completely unscrew the lower valve. We remove the housing, check its tightness, and assess the condition of the lower rubber ring. These parts do not carry a load, they are just a reservoir for liquid.

Next, unscrew the working cylinder and remove the piston. We carefully inspect everything for rust. If it is found, we get rid of it as thoroughly as possible. We unscrew the plunger, check its functionality, and inspect the O-rings. There should be no iron shavings inside, parts should not have dents.

Seals that have become unusable should be replaced with new ones. Do not forget to thoroughly rinse all valves from dirt and various deposits. We carry out the assembly, and all the repairs have been made.

How to fill the oil and bleed the jack?

Oil is poured through the neck on the side of the housing. This same neck is a level. Fill the oil, then you need to bleed the jack.

Bleeding the jack:

Raise the rod to the highest position without load using a lever
Then it is placed on its side, the filler plug should be on top
The plug is loosened and the rod is vigorously pressed into the cylinder. The operation is performed to squeeze out air from the working chamber.
The plug is closed, and 10-15 full lifts and lowerings of the rod are performed with a load of 40 - 45 kg.
At the last cycle, you should give an increased load and if the jack does not hold, repeat the procedure.

Source: https://gidropnevm.ru/gidravlicheskij-instrument/gidravlicheskie-domkraty/ygghjgjgremont-gidravlicheskogo-domkrata-butylochnogo-tipa-svoimi-rukami-mnenie-eksperta

Do-it-yourself hydraulic jack repair – algorithm of actions + video

Monolithic Wrench Jack

A jack is one of the most important tools in your arsenal; it will help you everywhere: repairing a car or equipment, carrying out a variety of construction and repair work. And if suddenly your device fails for some reason, you need to find out how to repair a hydraulic jack yourself!

Types and types of jacks: choosing the best

You will also be pleased with the wide variety of jacks, each of which has its own characteristics and distinctive features.

The most famous is the mechanical one, the main advantage of which is considered to be low cost. Additional advantages are: low weight, high lift level and fast working stroke. Among the disadvantages, the small support area is noted, which leads to little stability.
The next type is electrical equipment, it works from the electrical wiring of the machine, and the jack is controlled using a small block. The load capacity of the device reaches 2 tons, but the disadvantages include the large mass of the device and manual lowering, which requires a lot of time.
There is also a pneumatic jack, which runs on compressed air or a compressor. The advantages include low weight, reduced work costs, and a large support area.
But we will pay more attention to the hydraulic jack, because this model is most often used not only when repairing a car, but also during construction work, including work with reinforced concrete and reinforcement structures. They are able to demonstrate the highest possible performance, because the efficiency of the device reaches 80%, and the load capacity is about 200 tons, depending on the model. Unfortunately, we cannot do without difficulties. For example, you cannot precisely adjust the release height, so you should study the operating instructions for the tool in advance. During operation, in order not to cause the jack to break, it is advisable to monitor the condition of the oil seal, valves and the presence of oil . Yes, and you need to transport the tool wisely - only in a vertical position, so that the fuel does not simply leak out through the valve.

Like any equipment that carries enormous loads, devices can often break down, and therefore you always need to know how to repair a jack yourself. To be fully armed at the moment of breakdown!

DIY hydraulic jack repair

Any hydraulic jack is powered by fluid, and the main elements of the jack are the body, piston and oil.

If you decide to learn how to carry out repairs yourself, you definitely need to know what reasons can lead to breakdowns.

First of all, the design of the device could be “attacked” by corrosion, which leads to restrictions in the release of the mechanism. Naturally, jacks often break due to too much load, which causes the rods to bend.

There are some other considerations, including the need to change the oil. However, any repair is carried out practically according to the same scheme. And the first thing you need to know is how to disassemble the device, after which you can start replacing the fluid. Disassembling the tool is carried out in the following order:

Using wrenches, unscrew the fasteners;
Remove the fluid bleed valve and piston;
Carrying out a proper inspection, we check the quality of the valve and all gaskets - if you notice that they have become unusable, we simply change the elements of the jack;
We clean the mechanism from debris and other foreign elements, rinse the cylinder;
We check and change the old rubber if necessary;
The last step is to reassemble the tool in reverse order.

Naturally, after you assemble the jack, you should definitely check it for functionality! If the device starts working, great, but it’s not always possible to fix everything the first time. Perhaps the whole problem is in the oil?

Refilling the tool - how to fill the jack with oil?

Oil is the driving force of the device; it is the oil that presses on the piston, setting the rod in the desired position. Due to this, it is possible to lift almost any load.

If there is not enough oil in the device, the mechanism will not work. Many who start repairs for the first time skip this point, which ultimately leads to problems with the operation of the jack.

Oil change instructions:

In order to fill the jack with oil, you must first unscrew the plug and drain the old fluid. The next step is to clean the mechanism using washing liquid, which can be purchased at any hardware store.

By the way, it is quite difficult to completely wash the jack, especially for a beginner, because you will have to fill in the liquid at least two or three times, after which it is pumped, the liquid is added again and pumped again.

Draining the old oil is done in the same way - so that not a drop of old fluid remains inside the mechanism.

The container must be filled with oil completely, that is, until the liquid reaches the required level. At the same time, install the jack in a low position. To lower the rod to the lower position, be sure to turn the valve screw until it reaches the “drain” position.

After tightening the plug, we pump it five times, after which we add oil and tighten the plug again.

During the cleaning process, there will not be enough oil every time, and therefore it is necessary to pump until the “fuel” of our jack reaches the required level and bubbles stop appearing on the surface of the liquid.

Tips for replacing fluid and operating the device

As you have seen, repairing jacks yourself is a fairly simple job. However, of course, you don’t want to bring it to repair work, because this requires both time and effort to implement. That is why we have compiled a selection of recommendations from experts for you. If you follow them, the operation of your jack will become much easier, and repairs can be “pushed” further away.

Recommendations:

In order for the oil change work to proceed efficiently and correctly, it is necessary to remove any loads, and the device itself can be started to be used only after you have completely completed all the work and assembled the jack;
It is advisable to replace the “fuel” twice a year, and if you use the jack constantly, then at least once a month you need to carry out this work, and you must wash the entire mechanism every time;
You can choose any oil, but if you are going to use the device in the winter, be sure to use a synthetic solution. This will allow the mechanism to always be in “full combat readiness” for work;
Regardless of what time of year it is outside, it will be better if you can store the tool in a dry and warm place, otherwise the oil may simply freeze;
If it is necessary to carry out work in the winter season, remember that working in the cold for too long can lead to damage to the device, and therefore the use of the jack is possible in the most extreme cases and for a short time.

If you work using these methods, you can significantly extend the life of the jack. And expensive repairs, which can cost you a significant amount, can be “postponed” for an indefinite period, which is good news!

Source: https://remoskop.ru/remont-domkrata-gidravlicheskogo.html