Hydraulic distributor p 80 DIY repair

In detail: hydraulic valve p 80 DIY repair from a real master for the site my.housecope.com.

MTZ 80 is a universal wheeled row-crop tractor, which has been produced at the Minsk Tractor Plant since 1974. The long production period of this machine is provided by a successful design and the possibility of aggregation with a large number of additional special equipment, which makes the tractor multifunctional. The joint use of a variety of equipment is due to the high-quality, reliable and high-performance hydraulic system of the agricultural unit. One of the key elements of this system is the P-80 hydraulic valve for the MTZ 80 tractor.

Also, the features of MTZ 80 include:

the presence of a rear-wheel drive;
front placement of the power unit;
a large number of forward and reverse gears (18/4);
ease of repair and maintenance.

The successful design of the tractor, its technical characteristics and versatility ensure MTZ 80 is widely used not only in agriculture, but also in production, construction, housing and communal services and forestry.

The hydraulic system of the tractor is designed to control and provide energy to the installed various additional equipment, which can be completed with MTZ 80. It is made in a separate-modular version and includes the following main elements:

gear pump;
power regulator;
hydraulic magnifier;
separate control cylinders;
hydraulic valve MTZ;
hinge mechanism for mounting equipment;
PTO;
high pressure tubes;
connecting fittings;
oil tank.

Video (click to play).

Despite the large number of elements and assemblies used in the hydraulic system, the design over several decades of operation has made it possible to identify the arising shortcomings in the work and, as a result of the modifications carried out, to eliminate them.

At present, the operation of the hydraulic system is characterized by high reliability and high productivity, which allows the use of the most modern attachments and trailers for the MTZ 80 tractor. An important contribution to this is made by the P80 hydraulic distributor, which, with proper maintenance and correct adjustments, practically does not require repair.

Distributor R-80 3/1 222G of three-section type is used in the general-purpose hydraulic system of the Belarus 80 tractor and for the following functions:

protects the system from hydraulic overloads during lifting or forced lowering;
distributes the flow of hydraulic fluid, which is pumped by the hydraulic pump between the units of the system (hydraulic cylinders, hydraulic motors, etc.);
unloads the system at idle with neutral development due to the overflow of transmission oil into the oil tank;
performs the connection of the working volume of the hydraulic cylinder for draining the process fluid (when working in the neutral position).

In addition, the hydraulic distributor P80 3/1 222G serves as a basic device on which various modifications are made for use on loading units, excavators and road construction equipment.

The technical characteristics and parameters of the distributor can be found in the description of the P80 marking, where:

Р - distributor.
80 - nominal transmission fluid consumption (l / min).
3 - version of the process pressure (maximum allowable 20 MPa, nominal 16 MPa).
1 - type of operational purpose (autonomous use in general-purpose hydraulic systems).
222 - three special spools made according to option two.
D - hydraulic locks (check valves).

The valve assembly consists of the following key parts:

housings Р80 3/1 222G with connectors for valves and channels for supplying process fluid from the gear pump and channels for removing oil from the cylinders;
three spools, which are equipped with locking and auto-return mechanisms;
upper housing cover with integrated guides for spool control;
special overflow safety valve.

The principle of operation of the hydraulic distributor is based on the fact that when the hydraulic distributor P80 3/1 222G is connected to the hydraulic system inside the body, all spools and the valve form several combined passage channels for hydraulic fluid. There are three of them in total.

Discharge - Covers all spools and bypass valve.
Drain - with this option, only the spools are connected, and this channel provides the release of the waste fluid.
Control - also passes through all spools and an overflow valve, but at the same time is connected to the process piping from the pump.

The control of the spools, respectively, and the redirection of transmission oil flows through the appropriate channels provides four different positions when working with additional units and equipment. These operating modes include:

neutral,
rise,
sinking,
swimming position (lowering of working devices under the influence of their own weight).

Such a device allows, if necessary, to carry out repairs separately on each operating mode and connection diagram of the P80.

The most common malfunctions in the P80 3/1 222G hydraulic valve installed on the MTZ 80 tractor should be considered:

wear of the interface in a pair of valve body-spool;
violations in the piston of the hydraulic cylinder;
breakage of pump gears;
cracking of rubber seals;
leakage of hydraulic fluid through the connecting fittings;
damage to the oil drive tubes.

The design and device of the hydraulic valve allows the operator to repair these malfunctions with his own hands. In addition, a special repair kit recommended by the manufacturer for the P80 3/1 222G will help to facilitate the repair.

The reliable proven design of the P80 hydraulic valve allows it to be successfully used on a newer version of the Belarus 920 tractor, as well as on the multifunctional MTZ 3022.

Sectional hydraulic valves are designed to change the distribution of the fluid flow to the power elements of the hydraulic drive, start and stop the flow of working fluid in the hydraulic systems of stationary and stable machines and mechanisms. The basis of sectional hydraulic valves is the body, in which the main channels are made - an opening for entering the working fluid under pressure, openings for connecting to the consumer, an opening for the working fluid to exit into the tank; in the central hole of the body, with a diameter of 16 mm, there is a spool, which is driven by electromagnets.

Working pressure: up to 350 bar

Flow rate: up to 280 l / min.

Manual, electric control.

There are three types of hydraulic valves:

1. Crane hydraulic valves.

Valves of this type have a small flow capacity (up to 8-10 l / min), so they are most often used to supply a control signal to the main flow distributor. Their shut-off and control elements are made in the form of a cylindrical or conical valve. In the latter version, a tighter clamping of the plug to the valve seat is obtained due to the difference in areas between the upper and lower parts of the cone.

2. Directional spool valves.

In spool valves, the shut-off and regulating element is most often a cylindrical valve, which, depending on the number of channels (inlets) in the body, can have one, two or more belts. Accordingly, the first digit in the marking indicates the number of distributor connections. The second digit indicates the number of positions.

3. Hydraulic distributors are valve.

The valve manifolds are characterized by high tightness, which is undoubtedly their advantage. From this point of view, they can be recommended for use in hydraulic systems with high working pressure. According to the design of the locking and regulating element, this type of hydraulic valves is divided into ball and conical, and according to the method of switching - into valves with manual, electromagnetic and hydraulic control.

How does the designation of the distributor stand for?

An example of the designation of the P80-3 / 1-222 distributor, see.

80 - nominal flow rate (l / min);

3 - pressure version: nominal 16 MPa / maximum 20 MPa;

1 - code for operational purpose: for autonomous use in general-purpose hydraulic systems;

222. spool type: spool engagement positions

The spool switches off automatically from the “up” and “down” positions
Find out more about sectional valves in our lectures on hydraulics in the distance course “Basic Course in Practical Hydraulics”.

What are the technical requirements for hydraulic valves?

The main technical requirements according to TU 3.U.00235814-002-93 are as follows:

Constructive design - monoblock, valve-spool. 1. The hydraulic valve is an indirect overflow safety valve. 2. Control of spools. manual. 3. Type of spools - “1”, “2”, “3”, “4”, “5”. 4. Positions of spools - “Neutral”, “Raise”, “Forced lowering” - for all types of spools, “Floating” - for spools of type “1”, “2”, “3”. 5. The number of spools - 3 and 2 (on request). Example: Р80-3 / 1-222 - three spools of type “2”; Р80-3 / 2-44 - two spools of type “4”. 2. Nominal bore (mm) - 16. 3. Working fluid flow rate (l / min) o nominal - 80 o maximum - 120 o minimum - 20. 4. Inlet pressure (MPa) o nominal - 16 o maximum - 20 o minimum - 5. 5. Setting pressure of the safety valve for the third version (Pset., MPa) o maximum - 20 o minimum - 18 6. Internal tightness (maximum internal leakage through spool pairs): 0. Without hydraulic lock at Pstat. = 6. 7 MPa in 30min. (cm3) - 150. 1. If there is a hydraulic lock at Rstat. 70% of P nominal for 30 min. (cm3) - 24.

Note: The presence of hydraulic locks in the pressure chamber of the distributors when the spools are in "lift" position allows to reduce by 6.25 times the internal leakage in the pair "body - spool" or, in other words, to practically eliminate the eternal defect of the distributor - the subsidence of the load after it is lifted on tractors and agricultural machines ... Almost all tractor manufacturers are equipped with valves with a hydraulic lock: LTZ, MTZ, VgTZ, KhTZ, YuMZ. In distributors with a hydraulic lock, the drawdown of the cylinder rod when the spool is moved from the “neutral” position to the “lift” position with the upper or intermediate position of the load (Pstat. = 7 MPa, not less) in 30 minutes

for cylinder C80 (mm) - no more than 8

for cylinder Ts90 (mm) - no more than 6

Under what operating conditions is the valve's trouble-free operation ensured?

The connection of pipelines or hoses to the distributor is carried out only through intermediate parts (unions, flanges, etc.).

The purity of the working fluid in the hydraulic system must be at least 16 class GOST17216. The cleaning of the working fluid should be carried out in an effective way with a filtration fineness of 25 microns.

It is recommended to set the spool levers, which are not used when hitching tractors, to the “neutral” position.

When servicing tractors and carrying out technical maintenance, it is allowed, if necessary, to readjust the pressure of the safety valve to the values specified in the instructions for the machine, checking the adjusted pressure using a pressure gauge connected to the pressure chamber of the distributor. The adjustment is carried out at the maximum speed of the tractor engine crankshaft, taking into account the pressure value specified in the “Manual for the tractor”.

The pressure in the drainage hydraulic system at the outlet of the distributor should not exceed 0.5 MPa at the rated flow.

The distributor must be located on the machine no lower than the top of the oil tank.

P80-3 / 1 valves with any types of spools (111, 222, 333, 444) are used independently in the hydraulic systems of tractors, agricultural machines, industrial equipment, engineering equipment.

Spools types 1, 2, 3 provide a four-position valve operation:

Spool type 4 provides a three-position valve operation:

Distributors P80-3 / 4-. with spools of type 1, 2, 3 work only in conjunction with the power regulator of plowing 80-4614020 (50% of MTZ tractors, 30% of YuMZ tractors, 10% of LTZ tractors)

Distributors P80-3 / 2-. + P80-3 / 3-. with any types of spools they work only in pairs (six-spool assembly).

Distributor P80-3 / 4-. with spools of type 1, 2, 3, it is allowed to use it independently; for this, it is necessary to transfer the operating mode of the valve system to the distributor system. To do this, it is necessary to unload the neutral position from high pressure by connecting it to the drain by means of the K1 / 4 ″ threaded socket on the side of the third spool, after removing the metal plug.

Sectional valve repair

Before undertaking the repair of sectional hydraulic valves, we advise you to correctly assess your strength and knowledge in the field of hydraulics. We strongly recommend that you first take refresher courses in the specialty of hydraulics, in extreme cases, you can take distance courses in hydraulics, especially since you can order this course without leaving your home. This will cost you much less than if your sectional valve becomes unrepairable after your repair.

Knowing the device of one hydraulic valve of the working system of a front loader, it is easy to deal with the device of hydraulic valves of other models of front loaders. They all have approximately the same device (with their own characteristics) and the same principle of operation. Even if we compare valves with two control levers, one, or with a joystick, all the same, the principle of the mechanism remains the same.

From the figure below, it can be seen that there is nothing complicated in the device of the hydraulic valve of the working system. The body, spools, valves - these are the most important things to pay attention to when repairing and diagnosing.

The most serious problem in the distributor is the development of the spool-body in the seats. Longitudinal seizures and scratches in the valve body and, even the weakest, beating of the spool in the body in the transverse direction, which are palpable by hand, are indicators that the valve has worn out its resource. Spools are not interchangeable. The method of fitting the spool from another valve is not recommended, but it is often practiced by “craftsmen”. Sometimes this makes it possible to extend the life of the valve without costly repairs. Restoring the seating clearances in the valve housing and the spool is quite expensive and not everyone will undertake this.

The main reasons for lowering the boom and bucket in a static position are valve malfunction (valve needle clogged or worn out, debris has entered), leaking rubber seals.

If both the boom and the bucket are lowered on the loader, then the diagnosis should be started with the valve.

If the problem is only with the bucket or only with the boom, then the cause must be looked for in additional valves, cylinders (turning them off one by one), spool pair. If the working system is completely inoperative, we increase the pressure in the valve, check the needle, the working pump, the plug, the presence of foreign objects in the pipeline and the distributor of the working system.

Basic course in practical hydraulics. Minsk, 2002

The hydraulic distributor R-80-3 / 4-222 of the Minsk-made MTZ-82 and MTZ-80 tractors is used to redistribute the working fluid of the hydraulic system of these machines. This fluid flows from the pump and enters the required cylinder space. The flow can be automatically redirected to the oil tank after performing a certain function. The mechanism allows you to adjust the oil pressure in the system, hold the attachment in the desired position. Simply put, it is used to control the working equipment of the tractor.

This assembly has in its design a body, springs, top and bottom covers, a retainer, cavities and channels for oil movement, various valves, an adjustment screw, three spool valves, a sleeve, a ball, a booster and a retainer clip. The distributor is controlled by levers that have support in the form of a sphere.

The spool valves of the distributor have the form of cylindrical rollers, which have undergone high-quality processing. There are special grooves in strictly defined points. They are placed in high-quality and machined holes in the case. They pass through the provided channels and cavities. The spool valves move in them in the direction of the axes. It turns out that by closing some channels, the spool valves slightly open others. This changes the fluid overflow vector. The sliders are set in motion under the action of a lever that has four positions:

neutral,
rise,
free swimming,
forced lowering.

These positions have their own fixation. Only forced lowering implies the need to hold the lever with your hand. The spool valves have devices for automatic return to the "neutral" position from the fixed "lift" and "forced lowering" positions.

In the neutral position, the spool valves remain under the influence of the springs. They cut off the delivery channel from the cavities, the oil liquid is not able to get to the cylinders. These spools disconnect the oil path to the drain ports. Actions lead to the fact that the piston remains in a strictly fixed position. If oil begins to be supplied by the pump to the delivery channel, the lower element of the bypass valve is affected. Force is generated and the valve is opened. The oil begins to move to the bottom of the hydraulic distributor and is sent to the drain.

The control channel remains ajar. A little oil goes to drain and does not interfere with the opening of the bypass valve. In the floating position of the spool, both spaces can communicate with each other by means of a drain line. The liquid from the pump easily flows through the hydraulic valve and enters the tank through the same channels as in the "neutral" position. And in this position, thanks to the communication of the two cylinders through the hydraulic valve, the piston is able to move under the influence of the rod load.

In the "lift" or "forced lowering" position, one cavity communicates with the drain, the other with the discharge. The control channel is blocked by the spool belt, the oil pressure in the lower and upper parts of the bypass valve piston becomes the same. The valve of the hydraulic redistributor, under the influence of its own spring, goes down. The entry of the oil liquid to the drain stops.

When exposed to liquid, the piston in the cylinder begins to move and bring the mechanisms and working parts of the tractor into the operating position.The automatic return of the spool valves from the lifting position is obtained due to the generated pressure. The magnitude of this pressure is practically equal to the magnitude of the pressure when the safety valve is triggered. This valve is reconnected to the drain line. The pressure in it decreases slightly. But in another channel and space, it remains relatively high. After all, the bypass valve is still closed.

Due to the different pressures in the valve channels, the opening of the hole occurs. Oil begins to flow under the booster. The spool lock disappears. The spring returns it to the neutral position. In the "forced lowering" position, the channel is connected to the drain channel. The movement of the valve and the stopping of the spool fixation is carried out at a low pressure - 2 megapascals.

The hydraulic distributor has a relatively simple, reliable design. It does not require special skills for maintenance and minor repairs.

Stuck bypass valve in directional valve or body

1.1 Ball exit from groove

1.2 Spring failure

2.1 Destruction of surfaces spool pair

2.2 Particulate matter entering the gapbetween body and spool

3.1 Bursting of covers, gaskets by pressure inlid cavities

3.2 Watch p / n 1.1 and 1.2

3.3 Heavy contamination of the filterelement

4.2 The use of oil inappropriate to the established standard TU

4.3 Premature wear or destruction of the working surfaces of the spool and body by solid particles (p / p 1 and 2 )

6.4 The use of oil inappropriate to the established standard TU

6.5 Large internal leaks reducing efficiency

6.6 Similarly, see p / p1 and

26.7 Long-term oil operation at t> 80 С

6.8 Breakage of the lever when trying to switch a jammed spool

Note:
When qualifying these failures of work, it is necessary to make sure that the remaining connecting nodes and organs that are part of the hydra system are in full serviceability: hydraulic cylinders , hydraulic pumps . Reasons for failure of work in case of non-compliance of the valve modification with the requirements of the machine

Reasons for failures associated with factory defects in the manufacture of new distributors

Intensive wear of the surfaces of the spool pairs due to theirinsufficient hardness

Overflow jamming due to elliptical surfacepairing

The socket was not originally crimped or was pressed withskew

Method for assembling the hydraulic valve P80-3 / 1-222. Complete set of spools, installation of a bypass valve, safety valve, replacement of O-rings. General assembly for subsequent testing on a test bench.

Well, another machine is ready for my workshop and this time a grinding one. Also in the near future I will still make machines, write in the comments which one you want to see a homemade machine in my performance)

I would like to share my opinion about this technique with others!

Method for determining the direction of rotation of hydraulic pumps NSh-10, NSh-32, NSh-50 of different types.

I help a subscriber to build a homemade tractor, this is not my big contribution to a novice home-builder

I bought a hydraulic valve and decided to replace the repair kit.

Perpetual motion machine from an aluminum cylinder or Accumulator of the FUTURE original video

distributor part 2. After replacing the ball and adjusting the spring, everything became normal, but we will wait for spring, since now we cannot warm up the oil to the desired temperature, because the hinge does not hold at a temperature when the oil is warm-liquid.

The hydraulic distributor MTZ 82 is responsible for the position and operation of the attachments. This device is usually attached to the rear power cylinder bracket. The MTZ-82 tractor is usually equipped with the P-80-3 / 4-222 model. The main function of this unit is to distribute the hydraulic fluid that comes from the pump. The hydraulic distributor is controlled from the tractor driver's cab. Let's consider this device in more detail.

The hydraulic distributor consists of the following parts:

frame;
channels for the distribution of hydraulic fluid;
three spools;
springs;
valves;
adjusting screw;
retainer;
liners;
ball.

The hydraulic distributor, which the MTZ-82 tractor is equipped with, has four working positions: neutral, lifting, free and forced lowering.

Each position of the unit is fixed, the only exception is the forced lowering of the equipment. In this case, the operator is forced to hold the control lever with his hand.

The possibility of automatic return of the hydraulic valve to the neutral position is provided.

When the MTZ-82 tractor works with attachments, the following processes take place in the hydraulic valve.

In neutral position, the spools are fixed with springs so that hydraulic fluid does not enter the working cylinders. In this case, the piston of the cylinder is in a fixed position.

If the pump is pumping fluid into the system, the bottom valve opens. In this case, the bypass valve communicates with the drain through the control valve. As a result of this communication, a pressure drop is created, with the help of which the hydraulic system is relieved.

If MTZ-82 lifts attachments, the safety valve opens and the spring-loaded bushing is pushed out under the influence of the hydraulic fluid. As a result, the balls are released and the spool takes the required position.

In lowering mode, the working pressure in the hydraulic valve of the MTZ-82 tractor is leveled. This is achieved by closing the control valve with the spool. The bypass valve moves downward, as a result of which the flow of liquid is interrupted.

In the floating position, the hydraulic fluid supply channels communicate with the drain system. In this case, the hydraulic distributor operates in the same way as in the neutral position. In other words, the hydraulic system is unloaded.

If the operating pressure in the system exceeds the permissible load on the safety valve, the spools automatically move from the operating position to the neutral position.

This happens as follows: the safety valve is connected to the drain line, this leads to a pressure drop in this channel. The bypass valve is in the closed position at this time, so the pressure of the hydraulic fluid in the other channel remains quite high. As a result, the spool fixation disappears and the spring automatically returns it to the neutral position.

It happens that the spool does not return to the neutral position even with increased fluid pressure in the system. To prevent this from happening, it is necessary to pre-adjust the safety valve to the maximum allowable pressure in the system.

The hydraulic valve, which is installed on the MTZ-82 tractor, is usually sealed by the manufacturer. Safety seals may not be installed only if there is such an agreement between the companies.

The hydraulic distributor allows the MTZ-82 tractor to work with almost any type of attachment. As a result, the main load falls on this distribution unit.

Wear of working systems occurs mainly as a result of exceeding the maximum allowable pressure in the system or water hammer. Here's what the most common breakdowns look like and their possible solutions.

This is usually caused by a lack of oil in the hydraulic system. There may be several reasons for this phenomenon:

The oil pump does not work. It is necessary to turn on the unit, if necessary, adjust or repair the device.
Lack of hydraulic fluid in the tank. It is necessary to fill the container to the recommended level.
The bypass valve is stuck. Usually this is due to the ingress of debris into the hydraulic distributor of the MTZ-82 tractor.The problem can be eliminated by lightly tapping on the valve cover. If it does not help, the valve will have to be removed and flushed.
The flow area in the locking device is violated. It is necessary to find the problem area by checking the tension of the flexible hoses. Tighten the locking nut on the locking device.
The valve responsible for limiting the movement of the piston stroke is stuck. It is necessary to loosen the fixing nut, remove the stop and quickly move the valve control handle from the "lower" position to the "raise" position.
Deceleration valve clogged. To eliminate the problem, the union is removed and the valve is flushed.

overheating or oil leakage. Switch off the tractor to cool the system. Replace the valve of the hydraulic adhesion weight multiplier (HGP);
the structure of the sealing rings is broken. Worn parts need to be replaced.

Dispensing valve hole clogged. It is necessary to clean the valve and remove the blockage;
insufficient oil temperature in the system. It is necessary to increase the temperature of the hydraulic fluid to 45 or 50 degrees;
the spool is jammed. It is necessary to disassemble the distributor and eliminate the cause of the blockage.

The retarder valve may be incorrectly adjusted. To fix the problem, it is necessary to adjust the device;

Incorrect operation of the attachments of the MTZ-82 tractor is often associated with overheating of the oil in the hydraulic valve. Here is a list of reasons that can cause an increase in the temperature of the oil in the system:

The oil line is bent or crumpled making it difficult for the hydraulic fluid to circulate. It is necessary to straighten the tubes, or completely replace the entire oil line circuit;
the control handle of the hydraulic distributor is in the working position. In this case, it is necessary to move the lever to the neutral position and wait for the oil to cool;
system operation is incorrectly adjusted. It is worth setting the recommended parameters.

In order for the hydraulic valve of the MTZ-82 tractor to function without interruption, it is necessary to regularly inspect the constituent parts and service this unit.

Periodic maintenance is mainly limited to checking the oil level in the tractor's hydraulic system. For this, a dipstick is taken and lowered into a container with hydraulic fluid. The recommended level should be between the marks on the dipstick.

In addition, the frequent failure of the hydraulic distributor of the MTZ-82 tractor is associated with the use of low-quality oil. Therefore, it is necessary to use only the oil recommended by the manufacturer. By regularly checking the condition of the oil line, you can eliminate the loss of hydraulic fluid.

Back in 1974, at the Minsk Tractor Plant, the first wheeled tractors MTZ 80 rolled off the assembly line, distinguished by their versatility when performing agricultural work. Its features such as a rear axle drive, a front engine compartment, 18 forward and 4 reverse gears, as well as ease of maintenance and repair, made it popular not only in the fields, but also in production, in the construction industry, housing and communal services. and forestry.

The long history of the production of these machines is due to the fact that their design allows the use of a wide range of all kinds of attachments for special equipment. This, in turn, became possible thanks to the hydraulic system installed on the tractor, which is characterized by high performance, quality and reliability. Hydraulic distributor MTZ (model range R-80) is one of the most important mechanisms of this system.

As mentioned above, the MTZ 80 tractor has the ability to install additional attachments, the functioning of which is ensured by the tractor's hydraulic system. It consists of the following main units:

Hydraulic tank;
Filter;
Gear pump;
Oil pipelines;
Hydraulic distributor MTZ;
Filter safety valve;
Hydraulic enlarger (FGP);
Power (positional) regulator;
Hydraulic cylinders;
PTO;
High-pressure hoses;
Side and rear terminals;
Mechanism for attachments;
Connecting fittings.

As you can see, the hydraulic system contains a large number of different units and elements. During the long years of intensive operation of special equipment, a number of design flaws were identified and eliminated, due to this, the overall reliability of the system has significantly increased.

Modifications to the hydraulic system of the MTZ 80 tractor, which have given it high performance and reliability, now allow the use of attachments and trailed equipment that keep up with the times. The P80 hydraulic valve has a significant effect on this. The reliability of this device is so high that with proper adjustment and periodic maintenance, it rarely needs repair.

Let us consider in more detail the three-section hydraulic valve R-80-3 / 1-222G. It is installed in the hydraulic system of the MTZ 80 tractor (being, moreover, the basic element when making modifications to the devices used on loaders, excavators and other equipment) to solve the following tasks:

Protection of hydraulics against overloads during lifting or forced lowering;
Distribution of oil between elements of the hydraulic system (cylinders, hydraulic motors, etc.);
Reduces the load on the system when idling by draining fluid into the tank ("neutral position");
Keeps the organs of the working mechanisms in a certain position.

The hydraulic valve marking contains information on its technical characteristics and parameters. Consider how R-80-3 / 1-222G stands for: the first symbol indicates that we have a distributor in front of us, the next number shows the nominal flow rate of the working fluid (in this case it is equal to 80 l / min), followed by the working code pressure (we have 3, which corresponds to the nominal system pressure of 16 MPa with a maximum equal to 20 MPa), the unit under the fraction is the destination code (i.e. the device is designed to work autonomously in general-purpose hydraulic systems), 222 - show that in device 3 of spools of type 2, and the last symbol Г, indicates the presence of hydraulic locks in the device.

The main structural elements of the hydraulic valve are:

Body, top and bottom covers;
Spool control levers installed in the top cover;
Inlet and outlet channels in the housing for supplying circulating working fluid from the pump to the working cylinders and draining it into the tank;
Spools with locking and automatic return mechanisms;
Safety valve;

After the MTZ 82 hydraulic valve is connected to the tractor hydraulic system, the movement of oil inside the body occurs along one of three channels created by spools and a valve. Consider how they are formed and what they serve.

Discharge port - passes through all spools and safety valve;
Drain channel - passes only through the spools, it is needed to release the used oil;
Control channel - covers spools and a safety valve, at the same time being connected to the line supplying fluid from the pump.

By controlling the spools, it is possible to provide the attachment with different positions by redistributing the hydraulic fluid through the necessary channels. The modes created for mounted units are conditionally divided into four types:

Neutral position, used when this spool is not in use;
Rise;
Lowering;
Floating position, similar to neutral, but allows the implement to lower under its own weight

This design makes it possible, if desired, to carry out repairs at each separate operating mode and the connected circuit of the MTZ hydraulic valve.

Most often, you can encounter the following malfunctions in the MTZ hydraulic valve installed on the Belarus tractor:

Violation of the tightness between the spool and the valve body as a result of wear;
Worn out hydraulic cylinder piston;
Destruction of the gear pump;
The appearance of cracks in rubber seals;
Violation of the tightness of the connecting fittings;
Damage to the hydraulic lines.

The uncomplicated design of the device allows for its repair without the participation of service specialists. Often, machine operators do it themselves. In addition, a special repair kit recommended by the company that produces these products can significantly simplify the repair of the MTZ 82 hydraulic valve.

The P80 hydraulic valve, developed many years ago, due to its successful design and high reliability, is successfully used on modern tractors Belarus 920 and MTZ 3022.

An experienced and responsible team has been formed in our company, which has long been familiar with the equipment produced by the Minsk Tractor Plant. Therefore, we can easily find any spare part you need.In our catalog you will find about 1000 items of spare parts, among them there are both frequently used products and those that are rarely needed. This allows you to find everything you need for repairs in one place.

Video (click to play).

Realizing that the work of special equipment is associated with high loads and difficult conditions, we interact only with trusted manufacturers. This allows you to have no doubts about the high quality of the products in accordance with the declared technical characteristics.