DIY household compressor repair

In detail: DIY home compressor repair from a real master for the site my.housecope.com.

The compressor is a rather complex technical equipment, as it is used, it has the right to wear out and break down. In this article, we will consider all the methods of maintenance and operation to maximize its life. Execute DIY compressor repair, if he still broke, perhaps.

The reliability of compressor equipment largely depends on timely and quality maintenance. A large number of piston compressor breakdowns are the result of poor-quality cleaning of the compressed air (abrasive dust, water, and other inclusions). Application and timely replacement and cleaning of filter elements will delay compressor repair for a long time.

The main reasons why a reciprocating air compressor fails are:

Unfavorable operating conditions
Scheduled maintenance is not performed
Not competent service personnel

To ensure high-quality maintenance, operation and repair of the compressor with your own hands, it is necessary to solve all the above points.

The main difference between maintenance and compressor repair is that during repairs, certain parts are forcibly replaced, and during maintenance, parts are replaced as needed, depending on their actual condition.

A compressor is a device for increasing the pressure and moving gas to the required source (spray gun, grinders, wrenches, airbrushes and any other pneumatic equipment). The main equipment in demand in body repair has become a piston compressor, oil type. In piston, the volume of the working chambers is changed by means of reciprocating pistons.

They have a different number of working cylinders and distinguish them according to the following structural arrangement:

Video (click to play).

Horizontal
Vertical
Opposed
Rectangular
V and W shaped
Star-shaped

Before doing compressor repairs with your own hands, you need to study its technical structure. The photo below shows a diagram of a single-stage compressor, piston group.

Crankshaft
Frame
Connecting rod
Piston pin
Piston
Cylinder
Valve
Cylinder head
Valve plate
Flywheel
Oil seals
Crankshaft bearings

On the case near the electric motor there is an automation unit called a pressure switch. It can be used to adjust the compressor. It is possible to lower the pumped pressure or increase it.

If any defects are found (the appearance of knocking, jamming of rubbing parts, strong heating, increased consumption of lubricant, etc.), it is necessary to make repairs.

It is important to establish the definition of the type and volume of repairs at the stage of diagnosing the state of the object before repairs. Compressor malfunctions can be divided into two groups: technical malfunctions (working part of the piston group and malfunctions of electrical equipment). Below are the most common breakdowns:

Compressor (motor) does not start
The electric motor hums and does not rotate
Compressor not picking up speed
Knock in the cylinder-piston group
The cylinder is too hot
Performance has dropped
Strong vibration

The compressor will not turn on, the most common problem. The main and trivial thing that can be in this breakdown is that there is no voltage in the network.The first thing to check is the plug and wire for an open circuit supplying the electric motor. Using a special “tester screwdriver”, check if all phases are energized. Check the fuse, if present. Make sure that the starting capacitors are operational (for single-phase compressors, the voltage is 220V).

Pay attention to the pressure level in the tank (receiver). Perhaps the pressure is sufficient and the automation does not start the compressor, as soon as the pressure drops to a certain level, the electric motor will start automatically. This is not a breakdown, many people forget about this nuance and worry ahead of time.

The check valve can also become a problem if the compressor does not turn on. Also, a faulty automation unit (pressostat) affects the breakdown (on, off), the button on the unit itself may have become unusable.

If the electric motor does not start, hums, hums does not pick up the required speed, or stops during operation, this does not always mean its breakdown.

The main malfunctions of the electric motor that can interfere with its correct uninterrupted operation:

Low motor power (insufficient mains voltage)
Loose connections, poor contact
The check valve is out of order (leaking), thereby creating back pressure
Incorrect starting of the compressor (see operating instructions)
Piston group jammed (due to lack of oil level, overload)

If the electric motor of the compressor does not turn on at all and does not make sounds, then this indicates the following:

Mains supply fuse tripped
Overload protection tripped
Poor electrical connection (wiring problems)
The worst thing is that the electric motor burned out (there is often a characteristic smell)

One of the reasons for compressor breakdown is a faulty piston group. It is quite easy to recognize a defect in this system. They are usually accompanied by thumping, crashing, grinding and other sounds of a metallic nature. If the compressor knocks, then its discharge part is faulty, where there are many metal parts that interact with each other. Due to their friction and wear, there are extraneous noises and unpleasant sounds.

You should not start with such a breakdown; if possible, it should be eliminated as soon as you heard the first signs of their manifestation. The main faults if the compressor starts to knock and work loudly than before:

Crashed bearings, connecting rod bushings
The bearings on the crankshaft are out of order.
Worn out piston, rings, finger on the piston
Cylinder worn out
Loose cylinder and head bolts
Solid particle hit the cylinder
The cooling impeller is loose on the pulley

To repair these breakdowns, in simple cases, it is enough to stretch all the bolts and nuts. If the piston, cylinder, crankshaft or connecting rod are worn out, then a comprehensive overhaul is required. When repairing a piston group, it may be necessary to bore the cylinder, if it is badly worn out and has external defects, select a repair piston according to new dimensions. Possible piston system defects are listed below:

Changing the diameter of the piston, cylinder
Distortion of the shape of the cylinder mirror
Risks, scratches, scuff marks on the cylinder walls
Cracks in the main working part
Flange cracks and breakage

Read also: DIY voltage regulator repair

4. Monitor the general condition, periodically blow out dust and other contaminants. Pay special attention to the impeller on the electric motor, cylinder fins, air cooler, as they are used, dust and paint dust adhere to them, which reduces the cooling capacity.

5. Inspect the belt drive for wear and tension. When pressing on the belt at the midpoint, it should not bend by more than 12-15 mm. Broach all nuts and bolts. Periodically check the function of the safety valve, which serves to protect against overpressure due to a breakdown of the pressure switch.

Follow all of the above methods and you will delay the repair of the compressor for a long time.

Compressors for painting a car, inflating tires or pneumatic tools need regular inspection, maintenance and sometimes repair. This is especially true for reciprocating compressors, in which pistons, rings and other parts require frequent replacement. We will talk about the main problems and how to fix them.

The causes of compressor malfunctions can be forced operation, neglect of service times, design defects, natural wear and tear of operating equipment. So that the broken unit does not slow down the work, we will try to understand the reasons for the failure and correct the situation by doing the repairs ourselves.

A decrease in pressure in the receiver when pumping is stopped indicates that there is a leak somewhere in the system. A soap solution applied to the likely places of leakage will help to detect it:

compressed air line;
piston head valve;
receiver pressure relief valve.

A detected line leak can be sealed with tape and sealant. The tap must be screwed in all the way and, if the soap solution continues to bubble, then the valve is faulty and needs to be replaced. Installed using a sealing FUM tape. If both the route and the valve do not show a leakage, it can be concluded that the problem is in the piston head valve. To get to it, you need to bleed all the air from the receiver and disassemble the cylinder head. If, after cleaning the valve, it does not restore its functions, then it will have to be replaced.

The first thing to check is the voltage in the network, the integrity of the connecting cable, as well as the quality of the contacts. Then check the fuses and, if necessary, replace them with similar ones.A blown fuse can also occur if it is installed with an unreasonably low operation threshold. In this case, they must be replaced with the appropriate ones for your equipment. If, when installing new fuses, they blow out again, look for the cause in a short circuit.

Another reason may lie in the incorrect settings of the pressure switch on the receiver. To test this assumption, you need to bleed air from the tank and try to start the engine again. If it starts working, change the settings on the pressure switch.

Sometimes the engine starting is blocked by the overheating sensor during intensive continuous operation of the compressor. In this case, you need to allow the equipment to cool down, after which it will again work in standard mode.

In a situation where the engine is humming and no pumping occurs, the problem may be with the network. If the voltage drops below 220 V, the engine may not have enough power for the compressor to operate correctly. In this case, you can install a stabilizer in the network or, if the phase is overloaded, temporarily disconnect the electrical devices connected to it from the power supply.

If the voltage is not too different from the norm, it is possible that the pressure in the receiver is too high and resists pumping. In this case, the foremen recommend to turn off the compressor for a while and start it again after 15–20 seconds. If work is not restored, you need to check and, possibly, replace the pressure switch.

Pressure switch

Another reason could be a clogged by-pass valve, which should relieve overpressure. In this case, you need to remove and clean it. If the valve is destroyed, it must be replaced.

In some cases, the reason may be incorrect operation or malfunction of the voltage relay. It is difficult to repair it on your own, and if it is not possible to contact a service center for repair, you can replace it.

The operation of the automatic thermal protection is understandable in cases when the room temperature is high, there is a reduced mains voltage (check with a multimeter), or the installation works without interruption for a long time.

If everything is in order with the room temperature, voltage and operating mode, then the filter installed at the atmospheric air inlet is clogged. The filter must be cleaned, rinsed, dried and reinstalled. Such manipulations must be performed regularly, with constant work - daily. This reduces the load on the compressor motor and reduces overall system wear.

When painting, this situation leads to the rejection of the painted surface. The reasons for its occurrence can be:

the water from the receiver has not been drained for a long time;
contamination of the air filter at the inlet;
high humidity in the workshop.

The problem is solved depending on the cause of the occurrence. The accumulated water must be regularly removed from the receiver using the drain valve. The supply filter is cleaned or replaced. High humidity in the room can be dealt with by ventilation equipment or by installing additional moisture separators.

Filter drier

If the crank mechanism fails, you need to disassemble it and restore the loose hole for the crank. To do this, a new thread is cut taking into account the fact that the motor shaft rotates counterclockwise.

Possible causes of the problem are:

defects in piston rings;

oil contamination;

hauling connecting rod bolts;

insufficient clearance at the joints of the piston rings;

fastening pins are loosened.

If oil leaks, it may be necessary to replace a worn oil seal. It may also come time to clean or replace the oil filter, replace the retaining ring. To do this, the compressor will have to be disassembled.It is necessary to unscrew the fastening bolts on the front cover of the compressor and remove the guide pins with a return hammer. After that, screw in the guide pins and push the front cover of the compressor on them.To remove the front cover, you need to unscrew the oil supply pipe with an open-end wrench.From the front cover, you need to unscrew and remove the oil pump gear, gaining access to the bearing and pulling it out manually.After that, it is necessary to carefully remove the retaining ring and knock out the oil seal.To remove the locking sleeves, you need to warm up the installation site over the electric stove. Due to the different thermal expansion, the sleeves can be removed more easily.After that, it is necessary to remove the oil pump and remove and replace the oil filter.To check the quality of the oil, you need to remove the rear cover of the compressor and check if clean oil is supplied to the gears through the oil supply hole. The oil must be free of foreign matter.Let's start assembling the oil pump. At the first stage, we assemble the sleeve.After that, you need to install the bearing and bushing in the seat. We install the pump.You will need mandrels to install the oil seal. Craftsmen recommend using an anaerobic adhesive fixer. Check the seal for integrity, burrs or other damage. Clean the installation site with a clean, lint-free cloth. Install the packing ring and packing mandrel. Slide the oil seal into the seat. Remove the protective ring and mandrel. Install a new retaining ring.To install the front cover, you need to align the guide pins and slide the cover. Screw on the oil supply pipe and place the cover bolts on the adhesive sealant.Next, insert the oil filter and reinstall the rear cover. The assembly is complete.At the end of the repair review, we suggest you watch a video about compressor repair.

air compressor

The listed pneumatic tool is safer to work with than a power tool, for example. The pneumatic equipment cannot have a short circuit that can lead to electric shock and fire. That is why such a tool is widely used in car repair shops or when repairing a car with your own hands.

The air compressor is applicable to households and when it stops working, it needs to be repaired.However, the repair of compressors is not particularly difficult, it is quite possible to do it yourself.

To understand the problems of a compressor, you need to clearly understand what elements it consists of and what they are intended for. The compressor, in the minimum configuration, consists of a blower (an engine that creates an air flow) and a receiver - a container that contains compressed air. Reciprocating compressors are most commonly used.

One of the main requirements for a compressor is its safety. If the pressure in the receiver is not controlled, the compressor will burn out. There is a high probability that the receiver cylinder may explode. To prevent this, the receiver is equipped with an electronic relay that automatically turns off the compressor when the air pressure reaches a certain value.

The air compressor is equipped with a pressure gauge that indicates the amount of air pressure in the cylinder. A check valve is used to protect the compressor from negative influences. Its main function is to prevent air from returning back to the compressor when the unit is turned off or otherwise interfered with.

More complex compressor designs are characterized by additional equipment such as compressor automation. Usually in small compressors, the automation unit maintains a pressure of up to eight atmospheres using a pressure switch, turning on or off the power to the electric motor when the minimum or maximum pressure in the receiver is reached.

In this case, there are two pressure gauges: the large one shows the pressure in the tank of the receiver, the small one - at the outlet. The pressure switch can be equipped with an unloading valve. When the unit is stopped, it will open, making it easier to start the engine later.

In some models, a cooling radiator is provided on the pipes for supplying air from the compressor to the receiver.

Cooling the air results in less condensation in the receiver. Such a trifle in the design extends the service life of the automation.

The presence of a drain valve allows you to quickly drain the condensate from the receiver, because it is advisable to end each operation of the unit with this operation.

The safety valve releases the increased pressure in the receiver, if for some reason the automation does not work, which protects the compressor motor from overloads.

The air filter protects the piston system from sand, dirt, paint fumes.

The following types of compressors are distinguished:

Volumetric action - keep gas or air in a confined space, increase pressure. Among them are:

rotary, principle of operation - suction and compression of gas during rotation of the plates; the working volume decreases, this leads to an increase in pressure.
piston - pressure is created by the movement of pistons and valves; reliable in operation, but noisier than rotary ones.

Dynamic - provide compression by increasing the speed of gas movement, increasing its kinetic energy, which is converted into compression energy. Distinguish:

centrifugal - used for air exchange in mines;
axial or axial.

Consider how a piston-type compressor works, air or gas in it is compressed by a piston that moves through the cylinder:

When the piston (3) moves up the compressor cylinder (4), the working gas is compressed. The electric motor moves the piston through the crankshaft (6) and connecting rod (5).
The suction and discharge valves are opened and closed by gas pressure.
The diagram on the left shows the gas suction phase into the compressor. When the piston moves down, a vacuum is created in the compressor and the inlet valve (12) opens. Thus, the gas enters the compressor space.
The right diagram shows the gas compression phase.The piston moves upwards and the outlet valve (1) opens. The gas leaves the compressor at high pressure.

scheme of work

The blower itself produces an uneven air stream, which cannot be used, for example, for using a spray gun. The receiver saves the day by smoothing out the pressure pulsations.

Having replenished the stock of information about the compressor unit, you can repair the compressor yourself. A distinction is made between the following compressor system malfunctions:

The compressor unit blower does not start.
From time to time, the thermal cut-out is triggered.
When the compressor starts, the thermal cut-out is triggered and the fuse is blown out.
The engine of the unit runs, but does not pump air into the receiver, or does it slowly.
When the supercharger is turned off, the pressure in the receiver drops.
High moisture content in the air outlet.
Strong vibration from the engine.
The compressor unit works intermittently.
The air flow is consumed below the norm.

There are several probable reasons why the compressor will not start..

If the unit does not start and does not hum, check the supply voltage with an indicator screwdriver. If there is a phase, the connections of the plug to the socket are normal, it is worth checking the fuses that are subject to melting.

Defective fuses are replaced with others of the same rating. New fuses with higher current ratings must not be installed. If the fuses blow repeatedly, there may be a short circuit at the input to the circuit.

The compressor may not start due to incorrect operation of the pressure control switch or failure of the level settings. To check if this is so, the gas is released from the cylinder and the supercharger is started. If the engine is running, readjust the relay. Doesn't work - change the required part.The engine will not run when the thermal cutout trips, turning off the power due to an overload of the piston system. In this case, do-it-yourself compressor repair is to let the motor cool down for 20 minutes, after which the unit will return to normal operation.It happens that thermal protection is triggered regularly. This happens due to low voltage in the network or increased air temperature in the room. The voltage in the network must not be less than the lower limit of the range recommended by the manufacturer; it is enough to measure this value with a multimeter.In a poorly ventilated area, an air-cooled piston engine often overheats. The solution is to move the compressor to another well-ventilated room.The blower inlet filter may become clogged due to poor air flow, in which case it should be flushed or replaced.The problem is more serious if the thermal protection is triggered when the compressor starts and the fuse blows. Perhaps it is not designed for the power of the unit, then it is replaced with the appropriate one.The fuse can be blown due to an overload in the mains. It is worth checking and disconnecting some of the consumers that load the network. Repair of air compressors is difficult if the voltage relay does not work correctly or the bypass valve breaks down. In this case, it is best to seek help from a workshop or service.If the voltage in the network is too low, the electric motor of the compressor will not cope with the scrolling of the axis and will hum. It is worth checking the voltage in the network with a multimeter (must be at least 220V).If the voltage is normal, there may be too much pressure in the receiver and the piston cannot push the air. To eliminate this malfunction, manufacturers strongly recommend that you set the switch to the "OFF" position for 15 seconds, and then move it to the "AUTO" position.