Disassembling the refrigerator engine: detailed instructions with photos and diagrams

Disassembling the refrigerator compressor yourself is a task that requires not only technical skills, but also an understanding of the principles of operation of the cooling system. This unit, often called the “heart” of the refrigerator, is responsible for circulating refrigerant and maintaining a low temperature. However, over time, even the most reliable models Atlant, Indesit or Samsung may fail: excessive noise appears, the engine overheats, or the refrigerator stops freezing altogether.

In 80% of cases of compressor breakdowns, it can be repaired rather than replaced completely - but this will require careful disassembly In this article we will examine step-by-step dismantling algorithmthe necessary tools, as well as typical mistakes that lead to the final breakdown of the unit. We will pay special attention to safety measures: working with freon and electricity requires strict adherence to the rules.

If you have never dealt with refrigeration equipment, we recommend that you first familiarize yourself with compressor design - this will help avoid damage to critical parts, such as the stator winding or valve group. For experienced craftsmen, at the end of the article there are answers to complex questionsincluding fault diagnosis by sound and vibration.

Tools and materials: what you will need for disassembly

Before you start work, prepare everything you need. The absence of even one tool can lead to delays in the process or damage to parts. Here minimum setwhich will be required in 99% of cases:

• 🔧 A set of open-end and ring wrenches (keys of 8, 10, 12 and 14 mm are required)
• 🔨 Screwdrivers: Phillips (PH2), flat (3–5 mm), and also specialized for self-tapping screws with a hex head
• 📏 Caliper or micrometer for measuring gaps (critical when checking the piston group)
• 🧲 Magnetic holder for fasteners (so as not to lose small parts)
• 🔥 Blowtorch or hair dryer (for heating the solder on the tubes)
• 🛠️ Hammer with a soft striker (for carefully removing bearings)
• 🧴 Lubricant for compressors (for example, Almig ALM 32 or Bitzer BSE 32)
• 🧤 Rubber gloves and safety glasses (required when working with freon!)

A multimeter (checking the windings) and a manometric manifold (measuring pressure in the system) are also useful for diagnosing faults. If you plan a complete overhaul to replace the oil seal or. piston rings, additionally prepare:

• 🔄 Bearing puller (can be replaced with a homemade device made of metal plates)
• 🧯 Vacuum pump (for pumping out the refrigerant before disassembly)
• 📦 Repair kit for a specific compressor model (includes gaskets, rings, valves)

⚠️ Attention: If your refrigerator was manufactured before 2010, it may use refrigerant R-12 (Freon-12), which is prohibited for free circulation. To work with such equipment, a license is required. according to the nameplate on the compressor or in the device passport.

Design of a refrigerator compressor: diagram and key elements

To properly disassemble the engine, you need to understand its internal structure. Modern refrigerator compressors are divided into three types:

1. Piston —the most common (installed in 90% of household ones). models, for example Birusa or Stinol. They operate on the principle of reciprocating piston movement.
2. Rotary - compact, used in low-power refrigerators (for example, Midea or Haier). Instead of a piston there is an eccentric shaft.
3. Inverter - silent, with smooth power control (found in premium models LG or Liebert).

Below is a simplified diagram of a piston compressor - the most common type:

Critical feature: In compressors with a vertical cylinder arrangement (for example, Danfoss SC10H), the piston group is fixed with a lock ring, which can be easily damaged during careless disassembly. In horizontal models (for example, Embraco EGX) this element is absent, but there is a risk of piston distortion during assembly.

Before disassembling, be sure to photograph or sketch the location of all tubes and terminals - this will simplify reassembly. Pay special attention to three key components:

1. The place where the tubes are soldered (breaking the tightness will lead to freon leakage).
2. Attaching the valve plate (often fixed with 4-6 hexagon screws).
3. The position of the rotor relative to the stator (if assembled incorrectly, the engine will not start).

How to distinguish a faulty compressor by sound?

If you hear when you turn on the refrigerator:

- Loud knock —wear of the piston group or broken valve.

- Hum without starting —turn-to-turn short circuit or malfunction of the starting relay.

- Whistling —freon leakage through the seal or a crack in the tube.

- Clicks with a pause —thermal protection is triggered due to overheating of the windings.

Preparation for disassembly: draining freon and dismantling the compressor

Disassembly compressor always begins with pumping out the refrigerant. An attempt to open the sealed housing without first draining the freon will lead to its instant evaporation, which is dangerous for health (risk of frostbite of the skin and mucous membranes) and the environment. Here is a step-by-step preparation algorithm:

1. Disconnect the refrigerator from the network i. let it stand for 1-2 hours - this is necessary to equalize the pressure in the system.
2. Find service pipe (usually a copper tube with a diameter of 6-8 mm with a cap, located next to the compressor Atlant it is often hidden under a plastic cover.
3. Connect to the pipe gauge manifold (blue hose - discharge, red - suction, yellow - to the cylinder). Open the valve on the manifold and release freon into the tank. cylinder or special receiver. The pressure should drop to zero.
4. Pinch capillary tube (thin copper tube going from the compressor to the evaporator) with pliers - this will prevent reverse flow of freon.
5. Unsolder the tubes from compressor using a blowtorch. Heat the soldering area to the melting temperature of the solder (about 200–250°C) and carefully remove the tubes.

After draining the freon, you can begin dismantling the compressor. To do this:

1. Disconnect start relay (the black box attached to the compressor housing). Remember the location of the terminals - when reassembling, it is important not to confuse phase and zero.
2. Unscrew mounting boltsthat secures the compressor to the frame of the refrigerator (usually 3-4 bolts of 10 or 12 mm).
3. Carefully remove the compressor from the housing. Be careful - there may be oil left in the lower part.

⚠️ Attention: If, when unsoldering the tubes, you smell a strong burning smell or see black flakes in the oil, this is a sign turn-to-turn short circuit in the stator windings. In this case, disassembly may not help: you will need to replace the compressor or rewind the stator.

Drain the freon through the service pipe|Pinch the capillary tube|Unsolder the tubes from the compressor|Disconnect starting relay|Remove the mounting bolts|Remove the compressor from the housing-->

Step-by-step disassembly of the compressor: from the housing to the piston group

Now that the compressor has been dismantled, you can begin to disassemble it. The process differs depending on the model, but the general sequence of actions is as follows:

1. Opening the sealed housing

The compressor housing is sealed around the perimeter. To open it:

1. Clamp the body in a vice (through soft spacers so as not to damage the metal).
2. Use a hacksaw or a grinder with a thin disk to carefully cut the weld along the top edge. Cutting depth - 1–1.5 mm.
3. Remove the upper part of the body by prying it off with a screwdriver. Be careful - oil under pressure may remain inside.

2. Dismantling the electric motor

After opening the housing, you will see a stator with windings and a rotor on the shaft. To remove them:

1. Unsolder the winding leads from the terminal block (remember the color of the wire and its position!).
2. Remove the retaining ring securing the rotor to the shaft (use a puller or two screwdrivers).
3. Carefully pull the rotor out stator. If it “sticks”, lightly tap the shaft through a wooden spacer.

Checking the windings: Using a multimeter in ohmmeter mode, measure the resistance between the terminals:

- Between C (common) i S (start winding) —should be 20–40 Ohm.

- Between C and R (working winding) — 10–20 Ohm.

- Between S and R —the sum of the two previous values.

If the resistance is zero - short circuit, if infinity - break.

3. Disassembling the piston group

This is the most critical stage. Follow the steps:

1. Remove the valve plate by unscrewing 4-6 screws. Underneath you will find the intake and exhaust valves (thin metal plates).
2. Remove the piston along with the connecting rod. In some models (for example, Secop/Danfoss), the piston is fixed with a retaining ring - it must be removed with a puller.
3. Check the condition of the cylinder: if there are burrs or scratches more than 0.1 mm deep on the walls, you will need to bore or replace the liner.
4. Inspect the connecting rod bearings and crankshaft. Play of more than 0.1 mm on the liners is a sign of critical wear.

Typical problems of the piston group:

• 🔴 Ring wear: Leads to a drop in compression. The gap in the ring lock is checked (nominal - 0.2–0.4 mm).
• 🔴 Scuffing on the cylinder: Arises due to metal shavings or lack of oil.
• 🔴 Play in the connecting rod bearings: Diagnosed by rocking the connecting rod on a finger.

⚠️ Attention: If during disassembly you find aluminum shavings in the oil, this is a sign of destruction of the piston or cylinder. In this case, repairs are not economically feasible: it is cheaper to buy a new compressor.

Fault diagnosis: how to determine what exactly is broken

A disassembled compressor allows for detailed diagnostics. Below is a table of typical symptoms and their causes:

For accurate diagnosis, use the following methods:

• 🔍 Visual inspection: Look for signs of overheating (blackening of the windings), corrosion, mechanical damage.
• 📊 Resistance measurement: As described above, check stator windings.
• 💨 Checking compression: Connect the pressure gauge to the outlet pipe and briefly apply power to the compressor. The pressure should rise to 15–25 atm.
• 🧪 Oil analysis: Black color and burning smell are a sign of overheating; metal shavings - wear of the piston group.

If the compressor shows no signs of life at all (no humming, does not heat up), the problem may be:

• Breakage of the windings (checked with a multimeter).
• Malfunction of the starting relay (replace with a known good one).
• Breakdown to the housing (check the resistance between the terminals and the housing - it should be infinite).

Compressor repair: what you can repair with your own hands

Not all compressor malfunctions require its replacement. Here is a list of defects that can be eliminated at home:

1. Replacing the oil seal

If oil or freon oozes through the engine shaft, the oil seal is to blame. To replace:

1. Remove the retaining ring securing the oil seal.
2. Carefully remove the old oil seal by prying it with a screwdriver.
3. Install a new oil seal, having previously lubricated it with compressor oil. Press in all the way using a mandrel (you can use the old oil seal as a spacer).

2. Restoring the piston group

If the rings are worn or scuffed on the cylinder:

1. Replace the piston rings with new ones (select according to the size indicated on the old rings).
2. If there are scuffs on the cylinder, polish them with GOI paste or fine sandpaper paper (grit 1000–1500). Deep scratches can be removed by boring on a machine.
3. Check the gap between the piston and cylinder - it should be 0.05–0.1 mm. If the gap is larger, the piston or liner needs to be replaced.

3. Valve repair

If the compressor does not create the required pressure, the problem may be in the valves. To check them:

1. Remove the valve plate.
2. Check the tight fit of the valves to the seat (they should fit without gaps).
3. If the valves are deformed, replace them with new ones or polish the seat.

4. Rewinding the stator

If there is an interturn short circuit or a break in the windings, the stator can be rewinded. To do this:

1. Remove the stator from the housing.
2. Remove the old winding by heating it with a blowtorch.
3. Wind the new winding with a wire of the same cross-section (data can be found in the datasheet for the compressor).
4. Impregnate the winding with varnish for electrical insulation.

The difficulty of rewinding is high, so if you do not have experience, it is better to buy a new stator or compressor assembly.

⚠️ Attention: When replacing parts, use only original spare parts or analogues recommended by the manufacturer. For example, for compressors Embraco spare parts marked EG or NEare suitable, and for Danfoss — series SC or NL.

Assembling and checking the compressor after repair

Assembling the compressor is carried out in the reverse order, but taking into account several critical nuances:

1. Sealing the case

After installing all internal parts, the case must be soldered. To do this:

1. Clean the edges of the body and cover from old solder.
2. Apply flux (for example, F-38N) to the place of the future seam.
3. Using blowtorch and solder (for example POS-40), carefully solder the seam around the entire perimeter. The melting point of solder is about 200°C.
4. Check the tightness by immersing the compressor in water and supplying air under a pressure of 1-2 atm through the service pipe. The appearance of bubbles indicates a leak.

2. Evacuating the system

Before charging freon, the system must be evacuated to remove moisture and air:

1. Connect the vacuum pump to the service connection.
2. Turn on the pump for 15–20 minutes. The pressure should drop to -1 bar.
3. Close the valve and keep the system under vacuum for another 10 minutes - if the pressure does not rise, the tightness is normal.

3. Refilling with freon

For refilling:

1. Connect the cylinder with freon to the manifold (yellow hose).
2. Open the valve on the cylinder and slowly charge the system, monitoring the pressure using the pressure gauge. For R-134a the operating discharge pressure is 10–15 atm.
3. After refueling, check the operation of the compressor: it should start without knocking and excessive heating.

After assembly, be sure to:

• 🔹 Check the resistance of the windings (must correspond to the nominal values).
• 🔹 Make sure that the motor shaft rotates freely, without jamming.
• 🔹 Test run the compressor without connecting to the refrigerator (no more than 1-2 minutes).

⚠️ Attention: If after assembly the compressor gets very hot (more than 80°C 10 minutes of operation), turn it off immediately. This may indicate overload due to high pressure (clogging of the capillary tube) or turn-to-turn short circuit.

Frequently asked questions about disassembling the refrigerator compressor

Is it possible to disassemble the compressor without draining the freon?

No, this is extremely dangerous! Freon under pressure can cause frostbite to the skin and mucous membranes, as well as an explosion upon contact with an open fire. In addition, when the housing is opened, the refrigerant will instantly evaporate, which will make further diagnostics impossible. Always drain freon through the service pipe using a manometric manifold.

How to understand that the compressor cannot be repaired?

It is not advisable to repair the compressor if:

• The stator windings are burnt out (blackened, there is a smell burnt).
• The oil contains aluminum shavings (a sign of destruction of the piston or cylinder).
• The body has cracks that cannot be welded.
• The play on the shaft exceeds 0.3 mm (indicates critical wear of the bearings).

In such cases, it is cheaper and more reliable to buy a new compressor.

What oil to use for the compressor after repair?

The type of oil depends on the refrigerant:

• For R-134a i R-404A — polyester oil (POE, for example, Emkarate RL32H).
• For R-600a (isobutane) - mineral oil (MO, for example, Suniso 3GS).
• For R-22 —mineral or alkylbenzene oil (AB, for example, Bitzer BSE 32).

Never mix different types of oils - this will lead to the formation of sediment and clogging of the capillary tube.

How to check a compressor after repair without connecting to a refrigerator?

For a test run:

1. Connect the compressor to the power source via the start relay.
2. Apply power briefly (for 1-2 seconds), observing:
• The presence of extraneous noise (knocking, grinding).
• Heating of the housing (should be uniform, without local “hot spots”).
• Discharge pressure (should rise to 10-15 atm in a few seconds).

If everything is in order, you can connect the compressor to the refrigerator and refuel the system freon.

What to do if after assembly the compressor does not create pressure?

Reasons for lack of pressure:

• Faulty valves (do not close or burnt out).
• Clogged suction filter or capillary tubes.