I think it's called the evaporator/cooling element, the coils inside the refrigerator where the r134a gas passes through cooling it. About a week ago our refrigerator stopped working and I found what I thought to be the problem, there was corrosion on the condenser tubes on the bottom of the fridge allowing all the r134a gas to leak out (likely due to dressing spilling repeatedly in the fridge and leaking onto them). I went in and replaced the corroded sections of tubing, and then added a valve onto the tubing so that I could pump more r134a gas back into the system. After bringing the pressure up to slightly less than 10 psi (got this figure from the internet) by adding r134a the cooling element is pretty cold, but not near as cold as it should be. I'm thinking I may have gone wrong in the way I added the r134a, I've seen online where people vacuum all the air out before adding the refrigerant, which I did not do since I do not own a vacuum pump. This will be my next step, but I figured I would ask here since I don't know much about these things and vacuum pumps are fairly expensive
You'll need to evacuate all the air that leaked into the system.
The vacuum is also an opportunity test to see if the repair is done properly.
It's a similar process to refilling the AC in your car after it leaked so if you use the same fittings a car shop may let you rent/use their equipment.