DIY hydraulic valve repair t 40

In detail: do-it-yourself repair of the t 40 hydraulic valve from a real master for the site my.housecope.com.

Hydraulics of the T-40 tractor divided into a power steering system and a separate-aggregate hydraulic hitch system. These systems operate from one pump, but have different purposes. The hydraulic linkage system is used to operate the tractor with trailed, semi-mounted, mounted implements and machines. The power steering system is designed to reduce the force applied to the steering wheel.

Device and circuit

The hydraulic system of the T-40 consists of a gear pump, a hydraulic tank with a filter, a flow dividing valve, a hydraulic distributor, a hydraulic booster, locking devices, pipelines and hoses, remote and main hydraulic cylinders, and burst couplings.

T-40 hydraulics diagram: 1 - hydraulic tank; 2 - pump; 3 - flow dividing valve; 4 - spool; 5 - spool spring; 6 - filter; 7 - power steering; 8 - hydraulic valve; 9 - main hydraulic cylinder; 10 - external hydraulic cylinders.

Principle of action (work)

Oil from the hydraulic tank is fed to a gear pump, which pumps it into the control valve. The valve divides the oil flow into two branches: one goes to the hydraulic booster, and the other to the hydraulic valve of the hydraulic hitch system. The hydraulic distributor supplies the oil flow either to the hydraulic tank via the oil drain line, or to the hydraulic cylinder, or through the rear and side outlets directly to the hydraulic drive of the agricultural equipment.

Hydraulic system malfunctions

What to do if the hydraulics of the T-40 do not work?

Attachment does not raise to transport position:

1. Stuck bypass valve of the distributor - disassemble and flush the bypass valve.

Video (click to play).

2. Dirty relief valve - Disassemble and flush the valve assembly. Adjust it to a pressure of 130-140 kgf / cm².

The implement lifts too slowly or jerks:

1. There is not enough oil in the hydraulic tank - add oil to the upper mark on the dipstick.

2. Air leaks in the suction line - tighten the suction line connections.

3. Air leaks through the pump drive gear oil seal - it is necessary to replace the oil seal.

4. Increased leaks in the pump - the pump must be replaced.

The distributor handles do not automatically return to the neutral position from the working ones:

1. The spring of the safety valve is loose - adjust the safety valve.

2. The spring of the distributor spool booster is tightly tightened - it is necessary to adjust the response pressure by 100-125 kgf / cm².

Hydraulic pump drive T-40

The pump drive is made in the form of a ball clutch, which allows you to turn on or off the pump at a low crankshaft speed. The hydraulic pump drive is turned off when the tractor is used as a stationary machine, when the engine is started in winter, as well as in the event of a hydraulic booster or hydraulics malfunction.

T-40 oil pump drive: 1 - hydraulic pump; 2 - axis of the pump activation lever; 3 - pump drive housing; 4 - ball; 5 - pump shaft sleeve; 6 - ball bearings; 7 - pump drive gear; 8 - front sheet; 9 - axis of the drive gear; 10 - pump activation clutch; 11 - latch handle; 12 - pump activation lever; 13 - pump activation plug.

In case of spontaneous shutdown of the pump during operation, loosen the fastening of the drive lever and, turning it with further tightening of the bolt, find a position that contributes to stable switching on and off of the hydraulic pump.

The device of the engine of the T-40 tractor: piston, crankshaft, cylinders

The device and operation of the power transmission of the T-40 tractor

The device of the power supply system of the T-40 tractor: injectors, high pressure fuel pumps, etc.

Electrical equipment T-40: diagrams and device.

Hydraulic system: malfunctions and repairs.

Tractor T-40 - device, operation and repair

1. Malfunctions of the hydraulic valve and visible manifestation of failure:

The valve spool does not switch to one of the extreme positions or to neutral;
There is no movement of the hydraulic motor;
The movement of the hydraulic motor continues with de-energized electromagnets;
There is no pressure relief from the cavities of the hydraulic motor or pump;
The pressures in the cavities of the hydraulic motor do not equalize.

Possible cause of the malfunction:

No power supply to the electromagnet;>
Failure of the electromagnet;
Spool jamming;
Breakage of the return spring.

Troubleshooting method:

Check the status of the LED on the plug connector: if the LED does not light up, establish the cause of the break in the electrical circuit and eliminate it; if the LED is on or absent altogether - check the presence of a magnetic field using a special tester;
Pressing the button for manual control of the distributor, check the ease of movement of the spool; if the spool moves easily, replace the magnet; if the spool does not move or moves with difficulty, disassemble the valve and eliminate the cause of jamming, or replace the valve. If there is no manual control button, check the pressure at the pump outlet and in the cavities of the hydraulic motor. If the pressure deviates from the required values, replace the hydraulic valve, having previously checked the serviceability of the magnet using a tester;
Press the manual control button and release it. If, when lowering, there is no sensation of a clear return, remove the distributor cap and replace it.

2. Malfunctions of the hydraulic valve and visible manifestation of failure

Incomplete stroke of the spool when switching the valve;
Slow or irregular movement of a machine organ.

Possible cause of the malfunction:

Insufficient traction of the electromagnet;
Deformation of the spool pusher;
Ingress of foreign particles into the gap between the spool and the body;
Increased body wear;
Spring breakage.

Troubleshooting method:

At an AC magnet, feel the temperature of the case by touch and listen to the noise when it is turned on. Increased temperature and audible noise indicate incomplete travel of the magnet armature. Disassemble the hydraulic valve and establish the cause by examining the condition of the pusher and the magnet armature;
Disassemble the hydraulic valve, inspect the parts and, if their condition is normal, rinse and reassemble, controlling the ease of movement of the spool.

3. Malfunctions of the hydraulic valve and visible manifestation of failure:

Increased internal fluid leakage;
Slow movement of the working body of the machine.

Possible cause of the malfunction:

Valve body worn or edge breakage.

Troubleshooting method:

Determine the temperature of the valve body by touch. If the temperature is higher than normal, replace the hydraulic valve.

4. Malfunctions of the hydraulic valve and visible manifestation of failure:

Possible cause of the malfunction:

Ingress of foreign particles under the mounting plane of the hydraulic valve;
Loosening of the distributor or its covers;
Destruction of seals.

Troubleshooting method:

Visually check the location of the leak. Tighten the screws securing the distributor and covers. Dismantle the distributor, disassemble and replace the seal.

Leakage of directional spool valves is their main disadvantage, since it can also be the reason for their seizure during long-term "standing" in one position and high pressure in the hydraulics, which is the stronger, the more contaminated the working fluid.

The power steering of the T-40 tractor is designed to reduce the efforts applied during the rotation of the steering wheel and to transfer one-way rotation from the steering wheel to the driving wheels. Its serviceability is associated not only with maneuverability, but also with safety - the wheels are less sensitive to uneven roads, and the trajectory of movement remains even with serious injuries of the tires. Timely preventive maintenance of the T-40 power steering, disassembly, assembly, repair, carried out with high quality, will help to increase the tractor's controllability and make it as easy as possible to work on it.

Power steering is one of the elements of the T-40 steering structure. It is located under the hood, closer to the front. The main components that will have to be faced during repair or maintenance: covers (front and rear), stops, nuts, bipod, spool.

The power steering of the T-40 tractor operates according to the piston principle. The oil is metered by a spool inside the piston.

Algorithm of work of GUR T-40:

hydraulic fluid is supplied from a gear pump;
the spool valve distributes the flow to the rear linkage and steering of the tractor;
pressure is supplied to the steering column T-40.

When the steering wheel rotates, two nuts are displaced in relation to the piston as follows: one moves in the direction of the end, and the other moves away. Therefore, the oil flow always moves in one direction, aiming towards the open drain hole.

The price of power steering T-40 ranges from 10-13 thousand rubles, complex repairs will cost about the same amount. Therefore, making repairs with your own hands and performing maintenance yourself is the best option for the tractor owner. Thanks to the video, you can learn more about the repair of the T-40 steering column.

Disassembly of the T-40 power steering is carried out according to the following instructions:

disassembling the piston unit, the pin located in the rear nut is pressed against the stop;
the nut must be unscrewed and removed together with the spring washer;
the screw is pushed towards the front cover, then the spool with springs and stops is removed.

The assembly is performed in the reverse order, but the following tips should be followed:

make sure that during assembly the pin is on the side of the back cover;
the spool should move freely, without friction and jamming;
before assembling the power steering, the constituent parts are washed with clean diesel fuel;
the spool must also be flushed and treated with diesel oil.

Do not allow blockages or debris to enter the piston. This can lead to failure of the power steering or wear of components.

When installing and assembling the T-40 power steering, special attention should be paid to the position of the screw, since it is endowed with a multi-thread type thread. It will be necessary to choose the correct position of its entry, leaving a gap of 1 mm between the piston and the nut (preferably without deviations).

In order to properly install, it is recommended to follow the instructions below:

together with the cover and the front nut, the screw is inserted into the piston so that in the operating position the thickening of the tooth is turned to the bottom, and the pin is in front;
the position of the pin is fixed and the rear nut is screwed on.
The nuts are fastened with a slight tension so that the depth from the end hole of the rod does not exceed 17 cm. If tightened more, the pin may not be in place. A click will signal that the pin has entered correctly.

For the efficient operation of the power steering, it is recommended to periodically make adjustments, which can be easily done by hand. Adjustment refers to a number of measures: adjusting the valve, side clearance and the coupling of the shaft teeth. Valve adjustment should be approached with great care and the factory-installed seal should only be torn off in case of large errors, as there is a risk of deviations.

The valve is regulated as follows:

a pressure gauge is connected to the line in which the injection takes place;
the cork is unscrewed and an emphasis is placed between the bar and the bipod;
the locknut of the safety valve and the cap are unscrewed;
the engine starts up to the maximum rotations of the crankshaft;
The bipod must be turned to the side of the stop and the pressure of the oil passage through the valve must be adjusted with the steering wheel (the required range at temperatures up to 35 ° C - 80 kgf / m2, more than 35 ° C - 75 kgf / m2).

After completing the procedure, everything must be installed in its original place with the reverse sequence. Important! When the engine is working, the steering play should not exceed 20 degrees, otherwise the adjustment will not be accurate.

Adjustment of the clutch of the shaft teeth, as well as the lateral clearance, is carried out as follows:

the nut is unscrewed, while the screw is being held, the lock nut is unscrewed;
the screw is screwed into the cover in two turns;
the screw must be held while tightening the cap and lock nut to the desired position.

The steering gears of the T-40 tractor must be lubricated every 100 operating hours with a manual syringe filled with grease.

The maintenance process of the power steering of the T-40 tractor involves:

detection and timely elimination of oil leaks through the joints of component parts and gaskets;
topping up to the proper oil level;
washing of filter parts.

It is enough to carry out maintenance and preventive measures after every 100 operating hours.

To increase the controllability of the tractor, a special metering pump is installed instead of the standard power steering. "How to convert a power steering into a mountain?" - the most difficult question for those who deal with the T-40 tractor, since the procedure is multi-step and painstaking.

The conversion procedure involves the following steps:

the upper part of the power steering is disassembled, the shaft and internal components are removed from the piston;
in accordance with the piston diameter, 2 plugs are machined (thickness from 12 mm) and installed in the piston;
by automatic welding or a 2mm electrode, the piston is welded on both sides;
after that, a fitting is installed: straight or angled under the front, angled - back;
on both sides of the piston, hydraulic cylinder rings are installed - two protective rings and one, one extreme, rubber;
the piston returns to its original place;
the valve and the safety spring of the valve will need to be removed, and the hole, which will function as an oil drain, should be closed with a plug.

During installation, the metering pump is connected via a flow valve to the NSh. The placement of the metering pump itself depends on the wishes of the driver: mainly, it is located either directly on the power steering, or is mounted behind the cab. There are no factory guidelines on this matter.

A set of HSS parts fluctuates in the price range of 9000-11000 rubles, but the re-equipment of the steering system of the T-40 tractor is undoubtedly worth it. Knowing how to remake the steering of the T-40 tractor, you can also master the process of alteration on the T-25, T-150K, MTZ-80, MTZ-82, YuMZ-6 and others, because the algorithm of actions and the set of parts will remain approximately the same the same.

Attention, on October 20 (Saturday) from 9.00 to 10-00 Moscow time, the portal will be unavailable due to technical workYou can ask questions only after registration. Login or register, please.It is known that on the T-40 there is one oil pump for the hitch and for the steering one, which makes it difficult to lift the hitch, since 10-12 liters of oil goes to the steering one. Maybe someone tried to put the NSh-10 separately on the hydraulic booster. Please describe it. I heard that it is being adapted instead of the side PTO.Hello Victor. Recently I have been working on a T-40, but this is the first time I have heard about a problem with hydraulics. I collided with the helmsman, and the hydraulics are working normally, the main thing is that the valves do not hang and hold.hello it is so, but all normal tractors have two pumps. this nsh-32 can be turned off as unnecessary if there is another on the steering wheel. I just hitch rises faster, as I noticed in a certain position of the steering wheel.so I thought about another pump.And the steering does not wedge? Can the spool be tightened on the pig? ; I have the same problem, they advised me to tighten the spool, although the book says that it is pulled almost by hand. Although I do not see a problem in this.Forgot. Throw a nut on 6 under the spring in the distributor on the pump, it can help, sign off Image - Do-it-yourself repair of the t 40 hydraulic valve

something did not understand which spool to tighten?

Good evening, gentlemen, RUSSIAN breadwinners, I apologize, I did not quite understand which hand to turn on the spool and which to type and how to use the mouse then. How to become such a virtuoso specialist?

That there is no one to talk to

Victor, there is a distributor on the NSh, a nut is unscrewed at the end, a spring is removed, the piston is not to be reached, but to throw a nut into it by 6

And the spool is located in the steering one to remove the backlash and reduce the “gap” in which the hydraulics are less actin. I have the same turd on the T-40 (with the front end), but it does not interfere much or I got used to it, maybe the fact that the NSh is new is less noticeable

When you roll out a T-40 a couple of times a day in the steppe on a 200-liter barrel and with one jack, then you will find a spool, and you can turn it like that with your foot on the assembly.

did not miss anything?

When you roll out a T-40 a couple of times a day in the steppe on a 200-liter barrel and with one jack, then you will find a spool, and you can turn it like that with your foot on the assembly. mail did not miss anything?

Do you need it? Are you drawn to the breadwinners, or what?

RM
I don’t know you and you didn’t switch to me and I don’t need to write nonsense in a personal message

Well thanks for the helpful tech. advice, especially. mail twoyu mat, I will try to apply it, it may help, you are not very angry, please, you cannot constantly be in such tension, especially with a 200 liter barrel. And Dombarovka, if my memory serves me right, from Orenburg in the direction of Mednogorsk.

Guys, what you are talking about (a nut for 6 where to put it) is called a flow valve. A very nasty thing. A slight wear of the spool, and that's it, a hassle. Finding a new one is a problem. Why dont know. Moreover, the hinge does not always work chilo. Therefore, in order not to disassemble it every time, I simply turn the steering wheel all the way. The hitch immediately picks up cheerfully. Only I have a power steering MTZ, but I can't say anything about the T-40 amplifier.

By the way, how to attach the NSh-10 diesel to the T-40? It is for a diesel engine, since the bridge with the checkpoint is generally exotic for me. Not a T-40. There is no side vom. Maybe someone has any considerations?

Better find yourself a sensible tractor driver, otherwise I come across some gouges. From Orsk 100 km towards Svetly. Do not take to heart

Thank you for the topical question Artyom Oh, I was drawn to the breadwinner for a long time, but I was somehow busy, but now I decided to make up my mind, but the truth is that some guys here are trying to scare a fig - it won't work.

Guys let's be friends.

Once again, I apologize, gentlemen, I may be off topic, as I found “talking” only here, but honestly it's nice to “hear” real breadwinners.

Artyom, I also do not have a side PTO, although everything is native

Let me explain a little. Engine - T-40, front axle with steering column - MTZ, rear axle - cotton T-28. Hybrid. I use the power steering cavity as a hydraulic tank.

In the T-40, this is still the same gimor. Look at the power steering there is a valve that regulates the pressure. If the system wears out, you can tighten it a bit. This will help for a while.
Putting another pump is possible but difficult.At one time I sculpted a twin 3210. But the air gets in the way and the hose is added. In the cold, the drive cuts off. In short, this is the tractor of yesterday. While their grandfathers are still buying, sell and take something more reliable.

Of all thieves, fools are the most harmful: they simultaneously steal our time and mood. (I. Goethe)

Another installation option. True, I did not change, I saw. The pulley for the generator at the T-40 is two-stream. On one stream, through the nsh-10 belt for power steering. And to another generator. Also in the cold gimor but how it works.

Of all thieves, fools are the most harmful: they simultaneously steal our time and mood. (I. Goethe)

Read also: DIY journal bearing repair

Artyom, maybe it's better to put a combine dispenser, and a combine cylinder on the bridge (front end)? And powered from the same flow valve.

Device, operation, maintenance

Hydraulic pump drive of the T-40 tractor is a ball clutch that allows the pump to be turned on and off when the engine is running at low speeds. Turn off the hydraulic pump drive when the tractor is stationary, when starting the engine in winter, as well as in the event of a malfunction of the hydraulic system or power steering. In case of self-shutdown of the hydraulic pump during operation, loosen the clamping bolt of the lever and turn it relative to the roller.
Distributor R75-VZ The valve-spool type is designed to control the power cylinders and protect the hydraulic system from overloads.
The valve design is shown in Fig. 66.
The spools are installed in one position or another using the handles.
Moving the handle upward from itself corresponds to the "Raise" position; down to the middle position - "Forced lowering"; down on itself to failure - "Floating".
In the "Neutral" position, the oil supplied by the pump is passed through the distributor to the tank.

The “floating” position of the spool ensures the lowering of the implement under its own weight and follows the soil relief by the support wheel of the implement during operation.
The return of the spool from the "Raise" and "Lower" positions to "Neutral" at the end of the working operation occurs automatically, and from the "Floating" position, do it manually.

Ultrasound examination of the kidneys (ultrasound of the Kidneys Kiev) does not cause pain, it is necessary to lie still during the procedure, there may be slight discomfort, the gel will be cool and moist. The procedure will be as comfortable as possible and will end as quickly as possible to minimize discomfort.

During operation, remember that the automatic spool device works satisfactorily in the temperature range of the working fluid from 30 to 60 ° C. In case of deviations from the indicated temperatures, cases of failure of the automatic device may be observed, therefore, in these cases, at the end of the working operation, manually return the handle to the "Neutral" position.

Long delay of the handle in the working position can lead to premature pump failure and overheating of the working fluid.
In the distributor body, in addition to three spools, there are 14 bypass valves and 18 ball (safety) valves.
The safety valve is triggered at a pressure of 130-135 kgf / cm2.
All distributor springs, with the exception of the booster spring 6 and the safety valve spring 19, are unregulated. Adjust spring 6 with screw 5, and spring 19 of the safety valve with screw 20.These adjustments in operation are allowed as an exception - in the event of a discrepancy between the valve parameters and the technical characteristics. Readjustment of these springs should be done by an experienced mechanic in a repair shop.

The power cylinders installed on the tractor are of two standard sizes: the main cylinder with a piston diameter of 90 mm and two remote cylinders with a piston diameter of 55 mm.
Structurally, the main and remote cylinders differ from each other only in size.
The design of the cylinder is shown in Fig. 67.
The movable stop 12 can be fixed in any part of the rod, while providing adjustment of the piston stroke.
For long journeys with the implements raised to the transport position, close the valve 10. After the valve has blocked the cavity of the cylinder lowering, move the stop 12 to the stem plug.

Before lowering the implement to the working position, move the distributor handle to the "Raise" position to open the cylinder valve.
On tractors T-40 and T-40A, installation of external double-acting cylinders is provided, that is, when oil is supplied to both cavities of the lifting and lowering cylinder from the distributor. When connecting the hydraulic cylinders in this way, install a retard valve in the threaded hole of the lift chamber cover.

You have the opportunity to get acquainted with Transfers HC Salavat Yulaeva on only verified facts.

During operation, do not move the retarding valves from the opening of the cylinder lift cavity marked with the letter "P" to the lowering cavity "O", as this will lead to an increase in the pressure in the system and a change in the lifting speed of the implements.
In addition to connecting double-acting cylinders, cylinders can also be connected for single-acting. In this case, turn off the pressure chamber "O" of the distributor and cylinder. Muffle the side outlets on the tractor connected to the "O" cavity of the distributor with plugs, and remove oil from the lowering cavity of the cylinders and install the breather applied to each remote cylinder in the threaded hole of the cover opposite the letter "O".
Remember that when connecting single-acting cylinders, do not hold the distributor handles in the "Lower" position, since the lowering cavity of the distributor is plugged. This can lead to overheating of the oil and failure of the seals.
An exhaust fan is installed in the kitchen to remove excess moisture in the bathroom or eliminate food odors. Such devices are relatively inexpensive and easy to install and operate. Vortice offers axial exhaust fans as well as centrifugal exhaust fans for removing air through a duct system.

Om of the flow dividing valve, the main volume of oil is directed to the distributor P40 / 75.

RThe distributor P40 / 75 is used for separate control of the rear power cylinder of the hinged system and a pair of remote hydraulic cylinders connected to the hydraulic outlets on the T-40 (T-40A) tractor, located at the rear of the tractor and on the sides. The valve has a capacity of 40 to 75 l / min.

TO Instead of standard external cylinders, other mechanisms that operate on hydraulics (for example, a tipping mechanism for a dump trailer, etc.) can be connected to the terminals.

Twith spool (2) [Fig. 1] of the distributor are placed in the bores of the cast iron body (1). To control each of the spools, there is a separate handle, which occupies four fixed positions:

Rice. 1. Distributor P40 / 75 of the T-40 and T-40A tractors.

D) - Discharge line;

5) - Nut-cap of the spool control lever;

6) - The axis of the distributor control levers;

8) - Guide sleeve stop;

9) - Bypass valve spring;

10) - Bypass valve guide;

11) - Bypass valve with guide rod;

12) - Bypass valve socket;

14) - Booster ball valve;

15) - Channel for draining oil from the safety valve;

16) - Booster valve guide with throttling hole;

17) - Booster valve spring;

18) - Booster spring adjusting screw with throttling hole;

27) - Stopper of the retainer spring;

29) - Safety valve socket;

30) - Ball safety valve;

31) - Safety valve guide;

TO the distributor P40 / 75 is supplied with the discharge and discharge lines of pipelines. From each of the spools there is a pair of oil lines to which the cylinders are connected.

TOWhen the spools are in the "neutral" position [fig. 2] the oil flows freely through the distributor and then drains into the hydraulic tank. At this time, the channels for supplying oil to the cylinders are in a closed state. When any of the spools is moved to the “lowering” or “raising” position, one of the channels is connected to the discharge line, while the other channel is connected to the drain line. In this case, the bypass is closed and all the oil supplied by the pump is directed to the corresponding cylinder cavity.

Rice. 2. The movement of oil in the distributor P40 / 75 at different positions of the spool.

P) - Hole for supplying oil to the cylinder when lifting;

O) - Hole for supplying oil to the cylinder when lowering.

V In the “floating” position, both channels that lead to the cylinders are connected to the return line, and the oil flows freely through the distributor, just as in the “neutral” position of the spool. The fixing device, located in the lower part of the spool, holds the latter in certain positions and ensures its return to the "neutral" position at the end of the lowering or raising of the implement. Moving the spool to either side results in compression of the spring (26) [fig. 1], which sits between the shaped plates, as a result of which it seeks to return the spool to the "neutral" position. This is prevented by the locking mechanism, whose balls, under the action of the spring-loaded conical cup (24), diverge and jump into the grooves located on the inner surface of the holder (22). The resistance to displacement of the balls exceeds the force of the spring (26), as a result of which the spool is not able to return to the "neutral" position on its own.

POn completion of lowering or raising, when the piston of the hydraulic cylinder reaches its extreme position, there will be a sharp increase in pressure in the system. When it is 110-125 kg / cm 2, the ball valve (14) will open and the oil, passing along the plunger (19), will move it. The plunger will press on the conical cup, expanding the balls, which will converge and stop holding the spool, and the spring (26) will automatically return it to the "neutral" position. If the spool is in the "floating" position, there is no pressure in the system, the spool is returned to the "neutral" position manually, using a lever.

VThe viscosity of the oil has a direct effect on the performance of the automatic device described above.

Pwhen the oil temperature is above 60 or below 30 degrees. Celsius device may not work. In this case, as well as if it is necessary to stop lowering or raising, when the cylinder piston has not yet reached the end position, the return to the "neutral" position is performed manually.

ZA long delay of the lever in the “lowering” or “raising” position is prohibited, as this entails overheating of the oil and failure of the hydraulic system pump.

WITH To protect the hydraulic system from breakdowns and overloads in the event of an excessive increase in pressure in the distributor, a ball-type safety valve is installed.

On is located in the threaded hole of the distributor body and is connected to the channels by means of the discharge and drain lines.The spring (32) of the valve, which presses the ball valve (30) against the seat (29), is regulated to a pressure of 130-135 kg / cm 2. When the pressure rises to a given value, the oil from the discharge line (D), passing through the hole (C) of the bypass valve (11) into the cavity (B) and then through the drilling (A) to the safety valve, squeezes the ball valve (14) and goes into drain line. Due to the small size of the hole (C) between the discharge line (D) and the cavity (B), a pressure difference is formed, which causes the bypass valve to rise and connect the discharge and drain lines of the P40 / 75 distributor to each other.

WITHConsequently, the safety valve, equipped with small bores that do not allow the entire flow of oil to pass through, controls the operation of the bypass valve, which has a large capacity, forcing it to open if the permissible pressure is exceeded.

RThe valve devices are adjusted on a special stand by tightening the springs of the ball valves located in the spools and the safety valve to the required pressure. The rest of the springs cannot be adjusted.

PThe selection of spools to the holes (with a certain clearance) is carried out at the factory and during disassembly it is forbidden to change their places.

PWhen installing the spool into the body, it must be turned with the mark "O" towards the bypass valve.

PThe overflow valve (without spring) must move freely and without jamming in the body and guide sleeve (10) when it is turned to any position.

V During the assembly process, the tightness of the bypass valve is checked using kerosene. If the bypass valve is dirty or stuck, it must be removed from its seat and washed in diesel fuel.

PWhen installing the P40 / 75 distributor on the T-40 (T-40A) tractor, the outlet ducts of the distributor (marked with the letter "P" ("lift")) should be connected to the hole of the hydraulic cylinder, which is marked with the same letter.

At the same time, I went over the hydraulic valve: oil was leaking and one spool did not work. A repair kit was purchased to overhaul the hydraulic valve. The repair kit includes a complete set of O-rings and gaskets.

Hi ... I thought so right away ... I already looked after the Bulgarian ... but it's a pity to throw this one away 🙂 and the spare parts are all full g ... everything needs to be finalized with a file 😉

Hello Not a thankful job distributor bulkhead. It's all to blame for the disgusting quality of rubber parts. Faced with this more than once. Especially relevant in our 40s. where the distributor is in the cab and all the oil falls under your feet. Unfortunately, it is treated with the purchase of a new dispenser

Malfunctions and ways of their elimination are common for P75 and P150 valves.

The causes of this malfunction and remedial measures may be as follows.

The reasons for this malfunction and how to fix them may be the following:

The response pressure of the safety valve is equal to or lower than the response pressure of the automatic spool return device. This reason is eliminated by changing the adjustment of the actuation pressure of the automatic spool return device to I — 12 MPa (110—125 kgf / cm2) or the safety valve to 13.0—13.5 MPa (130—135 kgf / cm2) in repair shops.
The bypass valve hangs up, as a result of which the required pressure does not develop for the automatic device to operate. The remedy for this problem is described above.
The temperature of the working fluid in the tank is higher than + 60 ° С, therefore, the viscosity is insufficient; as a result of which there are large leaks of liquid through the gaps in the automatic return device of the spool. The temperature of the working fluid of the hydraulic system has increased due to a malfunction of the booster device, therefore, until the malfunction is eliminated, the tractor driver must manually return the handle from the operating positions to the "Neutral" position.The cause of the malfunction can be eliminated by cooling the working fluid to a temperature of + 60-30 ° C.
The spool automatic return device is working properly, but does not work due to a pump malfunction (it does not create the required pressure).
The spool filter is clogged and the hydraulic fluid does not flow into the booster device in sufficient quantity. The malfunction can be eliminated only by disassembling the spool - remove the sleeve, the gasket with the filter and wash it.

The spool (and hence the handle) is not fixed when it is installed in the operating position ("Raise" or "Forced lowering") or returns to the neutral position until the end of the full stroke of the piston in the cylinder

The causes of the malfunction and remedies may be as follows:

The actuation pressure of the booster device (automatic spool return device) is below 11 MPa (110 kgf / cm2) and below the operating pressure that develops in the power cylinder when the mounted machine is lifted. Consequently, the actuation of the booster device occurs earlier than the raising of the machine to the extreme upper position. To eliminate this cause, it is necessary to adjust the booster device for a pressure of 11-12.5 MPa (110-125 kgf / cm2).
The mass of the mounted machine is greater than that established for this tractor or there is a lot of soil resistance when lifting the machine. In this regard, the fluid pressure in the power cylinder reaches a value greater than the actuation pressure of the booster device, and therefore the spool does not lock. In this regard, it is necessary to pay attention to the correctness of aggregation and to the depth of travel of the working bodies of the mounted machine. In this case, replace the mounted machine with a machine of less weight or set the required tillage depth.
The spool booster valve is not sealed due to foreign particles entering the valve seat or the gap between the booster and spool. Due to a leak in the booster valve, the automatic spool return is activated at lower pressures. This malfunction can be eliminated by holding the distributor handle five to seven times in the working position after the end of the working stroke of the power cylinder piston in order to flush foreign particles from the parts of the booster device with the flow of working fluid. If this does not eliminate the malfunction, then it is necessary to sort out the spool assembly, rinse it in diesel fuel and blow it with compressed air.
The temperature of the working fluid in the tank is below + 30 ° С. The operation of the distributor on a cold working fluid (high viscosity) causes a slow landing of the ball on the edge of the inlet hole. In this regard, the piston of the power cylinder reaches its end position earlier than the booster valve closes the inlet opening. Therefore, premature decoding occurs.
The calibrated hole of the retard valve is clogged or the calibrated hole does not match the diameter of the cylinder. Therefore, an increase in the pressure of the liquid in the booster device occurs and premature decalcification occurs. To eliminate the malfunction, it is necessary to clean the calibrated hole and flush the fitting in diesel fuel or check the correspondence of the calibrated hole diameter to the cylinder diameter. For cylinders Ts55, Ts75, Ts90, Ts100, Ts110, Ts125, Ts140, the hole diameter should accordingly be 2.5; 3; 3.5; 4; 4.5; 5.5 and 7 mm.
Incorrect installation of the retarding valve in the power cylinder. In this case, it is necessary to swap the fitting with the retarding valve to the second fitting of the cylinder, i.e. install the fitting with the retarding valve in the cylinder so that when the mounted machine is lowered, the working fluid passes only through the calibrated hole.
The oil line shut-off device does not allow the working fluid to pass through.In this case, the mounted machine rises slowly or does not rise at all or hangs in an intermediate position, and the pressure in front of the booster quickly increases, which leads to premature release. The cause of the malfunction is eliminated by tightening the union nut of the locking device to failure. If the locking device is faulty, it must be replaced or freed from balls, springs and crosses, and then tightened the union nut.
Jamming in the seat of the piston stroke adjustment valve or the gap between the stop and the shank of the piston stroke adjustment valve is less than 10 mm. In this case, the oil line in the power cylinder is closed and the pressure in the booster device rises, which leads to the premature operation of the booster device. This malfunction can be eliminated in the first case by lifting the valve with pliers by the shank, and in the second by lifting the movable stop on the power cylinder rod at a distance of 20-30 mm from the valve shank.
Retainer wear. In this case, you need to check the lock while the pump is not running. If it does not hold the spool in working positions, then worn parts must be replaced.

Video (click to play).

When the spool is set to the “Forced lowering” position, the mounted machine falls quickly, caused by the absence of a washer with a calibrated hole in the retard valve. The malfunction is eliminated by installing a new washer with a calibrated hole with a diameter corresponding to the diameter of the cylinder.

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