Installation of a pass-through evaporator

If the leak is on the “return”, then this is not such a difficult case; very often local corrosion of the aluminum tube occurs at the point of its contact with a foreign body (for example, a capillary tube covered with heat shrink passes through, creating heterogeneity of metals and conditions for rotting or thermostat contact).
The return line runs from the compressor to the evaporator in the foamed rear part of the cabinet; to access it, you need to remove the condenser and use a knife (sometimes it’s convenient to use a chisel) to cut out the foam along the tube, after which you need to apply pressure to the system (for example, with a large R410 cylinder, its pressure is enough for diagnostics, it is dry and always at hand compared to Nitrogen). Next, we wash the entire surface of the tube, look for the leak and seal it, if there are several leaks, we change the return line completely.

One of the alternative ways to seal a leak is a leak sealant; this is a modern tool and craftsmen have not yet formed a clear opinion on its use. Initially, the Italian company ERRECOM (the author of the sealant) produced only for R134, based on car air conditioners, then they began to make it for R600, which is distinguished by its white color and smaller size
In fact, experts agree that sealant helps in 60-70% of cases for R134 and 40-50% of cases for R600, it all depends on the shape and location of the hole

If it was not possible to eliminate the leak using a sealant and it was not possible to localize it in the return line, they use the method of installing a new evaporator, the main problem is in aesthetics, the new evaporator is hung inside the refrigerator compartment, the tubes are led out, one is connected to the freezer compartment, the second goes to the compressor.
As a rule, evaporators are made of sheet aluminum and already have a transition from aluminum to copper at the factory; when soldering, you need to be careful not to damage this unit, since soldering copper to copper is much easier than copper to aluminum. To protect the joints, craftsmen use an unnecessary wet rag, which is wrapped around the joint

Half the trouble is hanging the evaporator, which should at least somehow aesthetically suit the client; you also need to redo the compressor operation control system.
If the compressor is turned off using a thermostat, then there is no problem, we bring the tip of the thermostat to the evaporator and attach it closer to the outlet, in special holes where a plastic socket is screwed in, pressing the tip of the thermostat

There is an opinion that copper tubes do not rot and if you make an evaporator from them, it will last forever. Fans of these beliefs view the entire evaporator from the back, tear it off the plastic wall (often it is glued with foil tape), bend new rolls using a pipe bender and glue it to the wall, intimidating it back.
In my opinion, this method has a very big disadvantage, copper does not absorb heat well, therefore the compressor will work longer and rest less, which will ultimately lead to at least large electricity bills and, at most, breakdown of the compressor