How to disassemble the engine on a refrigerator: step-by-step instructions

Independent intervention in the internal structure of a refrigeration unit is a complex technical process that requires not only accuracy, but also a deep understanding of the principles of operation of thermodynamic systems. Most often, the need disassemble the engine on a refrigerator occurs when the compressor, which is the “heart” of the entire cooling system, fails. Owners of household appliances decide to take this step, wanting to save on the services of service centers or find a rare spare part for a retro model.

However, it is worth immediately noting that a complete disassembly of the compressor itself (opening the sealed casing) at home is almost impossible without special tools and often economically inappropriate. Typically, this term means dismantling the entire assembly from the niche of the refrigerator, disconnecting the starting relay and filters. Inverter and linear models require an even more careful approach due to complex control electronics.

Before taking up the tool, you need to understand the level of risk. Incorrect operation may result in refrigerant leakage, electric shock, or complete failure of the unit. This article describes in detail the process of safely removing the compressor unit for diagnostics or replacement.

Fundamental structure of the compressor unit

To correctly perform dismantling, you need to clearly understand what exactly you are dealing with. The compressor in a domestic refrigerator is a sealed metal cylinder or sphere, inside which there is a piston group, valves and an electric motor. All these elements are filled with oil and operate in a closed circuit. From the outside we see only the tube terminals and the electrical unit.

The key element for diagnostics is start relay. It is this that supplies the starting impulse to the motor windings. Often the breakdown lies in this small plastic block, and not in the motor itself. It is also important to consider the type of refrigerant: old models using freon R12 and new ones using R600a (isobutane) require a different approach to safety when the system depressurizes.

In modern models, such as LG or Samsung, can be installed inverter compressors. They differ in the method of fastening, the presence of a frequency converter and the absence of a classic starting relay in its usual form. Disassembling such components requires a preliminary study of the electrical circuit of a specific model.

⚠️ Attention: Inside the compressor there is a mixture of oil and refrigerant under pressure. Opening a sealed case (“grinder” or hacksaw) without special equipment for gas is prohibited by environmental regulations and can be hazardous to health.

Understanding the design helps to avoid fatal mistakes. For example, knowing that the suction tube usually has a larger diameter than the discharge tube will help you avoid confusing them when you subsequently install a new unit.

Required tools and safety measures

High-quality preparation of the workplace and the availability of the right tools are 50% of the success of the operation. You will need a set of wrenches, pliers, side cutters and possibly a pipe cutter if you plan to replace the filter drier. To work with electricians, a multimeter is indispensable, allowing you to check the integrity of the windings the presence of voltage.

Pay special attention to protecting your hands. The metal edges of the refrigerator casing and the compressor itself may be sharp. In addition, during dismantling, technical oil may leak out, which is difficult to wash off and irritates the skin. You should work in a well-ventilated area, away from sources of open flame, especially if the system circulates isobutane.

• 🛠️ A set of screwdrivers (phillips and flathead of different sizes) for removing panels.
• 🔧 An adjustable wrench or a set of open-end wrenches for unscrewing mounting bolts.
• 🔌 Multimeter for checking winding resistance and circuit integrity.
• 🧤 Protective gloves and glasses to prevent injury and oil penetration.
• 🔦 A powerful flashlight, since the compressor niche is often poorly lit.

Do not forget about basic electrical safety. Before starting any work, the refrigerator must be unplugged at least 15-20 minutes before disassembling. This time is necessary to discharge the capacitors in the starting equipment.

Access to the motor: removing the protective panel

The compressor is almost always located in the lower rear part of the refrigerator. To access it, you need to remove the rear panel of the niche. In most models, it is secured with latches or several screws. Be careful: the plastic becomes brittle over time and can crack if handled carelessly.

After removing the cover, you will have a view of the “black barrel” of the compressor, the condenser (radiator grille) and the tube system. Access is often difficult due to the dense layout. In some models Bosch or Siemens you may also need to remove the lower plinth or even dismantle the condenser grill itself by unscrewing its fastenings.

Visually inspect the unit for obvious damage: swelling, traces of soot, oil smudges. If traces of oil are visible on the compressor housing, this is a sure sign of a seal failure or dry operation. Also check the condition of the rubber vibration dampers on which the engine is installed.

⚠️ Attention: Do not bite off the copper tubes with wire cutters right away! This will cause instant release of refrigerant and scattering of oil. The tubes are sawed only after freon has been evacuated or if replacing the compressor is already inevitable and the system is empty.

For the convenience of further work, it is recommended to photograph the location of all tubes and wires. This will help you avoid confusion when assembling or installing a new unit, since the color marking of the wires may not be obvious.

Disconnecting the electrical part and relay

The next critical step is disconnecting the electrical. On the compressor body there is a plastic box in which the contacts of the starting and protective relay are hidden. You need to remove it carefully, using a flat screwdriver to pry up the latches. Inside you will see a terminal block and wires.

First, disconnect the ground wire (usually yellow-green) that is screwed to the motor housing. Then remove the connector from the start relay. In older models, the wires can be twisted and insulated with electrical tape - such insulation must be carefully removed without damaging the wires if you plan to reuse the relay.

Checking starting relay is a mandatory step. Often it is its breakdown (burning of contacts or destruction of the starting tablet) that simulates an engine malfunction. The relay can be easily removed from the compressor pins. Shake it: if a ringing is heard inside, it means that the ceramic insert is broken and the relay needs to be replaced.

If you are planning to install a new compressor, the wires can be bitten off, leaving room for twisting. If the goal is diagnostics, use tweezers to remove the terminals so as not to damage the contact pads on the winding terminals.

Removing the compressor and disconnecting the tubes

The engine itself is attached to the metal frame of the refrigerator on four legs with rubber shock absorbers. Some designs use two studs with nuts. You need to unscrew the nuts with a wrench, holding the stud with your other hand so as not to turn it. Rubber bushings can become stiff over time; they must be carefully removed.

Now the most crucial moment is disconnecting the copper tubes. There are only three of them: suction (comes from the evaporator), discharge (goes to the condenser) and a short sealed (blind) for charging with freon. To dismantle the tubes, cut them with wire cutters or saw them with a hacksaw 5-10 cm from the compressor housing.

After disconnecting the tubes, the compressor can be removed from the niche. It is quite heavy (weighs from 8 to 12 kg), so hold it with your second hand. When tilting the compressor, residual oil may leak from the cut tubes - substitute a container.

After removing the motor, it is recommended to turn it over and drain the oil into a measuring container. The volume and color of the oil can tell a lot about the condition of the system: if the oil is black and smells like burning, it means the windings have overheated.

Opening a sealed casing (for advanced)

If your goal is not a replacement, but rather repairing the internal part (replacing valves, connecting rod), you will have to open the housing. This is a complex operation that requires precision. The body consists of two hemispheres, butt welded. The seam must be carefully passed with an angle grinder (“grinder”) with a thin disk or a hacksaw.

The main task is not to damage the internal parts: stator, rotor, plate valve and tubes inside. You need to cut strictly along the weld seam, constantly monitoring the depth of the cut. After passing the circle around the perimeter, remove the top cover by prying it off with a screwdriver.

Inside you will see an electric motor and a piston group immersed in oil. To diagnose breaks in the stator windings, it may be necessary to visually inspect them for blackening of the varnish. Mechanical damage to the piston group (scuffs, broken valves) is usually visible to the naked eye.

⚠️ Attention: Assembling a sealed housing at home is impossible without argon welding. After repair, the unit will remain leaky. Therefore, opening it makes sense only for in-depth diagnostics, training, or if you are planning to convert the refrigerator for other tasks (for example, a compressor for an airbrush).

The cost of professional welding of the case often exceeds the cost of a new compressor. Therefore, for a household refrigerator, this method is considered a dead end.

Assembly and performance testing

If the compressor was replaced with a new one, the assembly procedure is reversed. The new unit comes with plugs on the tubes - they need to be removed at the last moment to minimize contact of the internal volume with moist air. Moisture in the system is the main enemy; it turns into ice plugs.

The tubes are connected using the copper-copper or copper-steel soldering method (steel is often used for the discharge tube). The use of soldering is mandatory; no clamps or adhesives are suitable here, since the system operates under high pressure and in an aggressive environment.

After mechanical assembly, the system is vacuumized with a special pump for 15-20 minutes to remove air and moisture, then charged with the calculated amount of freon. Only after this can you apply voltage and check operation.

• 🔍 Check the tightness of all connections with a soap solution.
• ⚡ Make sure that the starting relay clicks and the engine starts.
• 🌡️ Monitor the temperature of the condenser (sidewalls or rear grille) - it should warm up evenly.

If the refrigerator begins to gain cold, and the compressor operates cyclically (turns on and off according to the thermostat), the operation can be considered successful. However, remember that without professional equipment, refueling and vacuuming are impossible.

Frequently asked questions (FAQ)