Proper lubrication of the compressor is key to ensuring the long-term operation of the entire air conditioning system in the cabs of agricultural, special and commercial vehicles. Today, we will look at the technical process of adding oil to a depressurised air conditioning system using an oil injector.
This method allows for precise dosing of compressor oil and prevents excess air from entering the circuit.
Preparation stage
Before starting work, ensure that the system is completely evacuated (the refrigerant has been removed) and that the vehicle’s engine is switched off.
Important: Do not mix different types of compressor oil in the air conditioning systems of agricultural, special and commercial vehicles. Before refilling, ensure that the new compressor oil is fully compatible with the oil already in the system, or thoroughly remove any residues of the old oil.
Procedure for adding compressor oil
Step 1. Connecting the equipment
Connect the pressure gauge manifold, oil injector and vacuum pump as shown in the schema (see photo below). Check that all valves (A, B, C) are in the closed position.
Step 2. Start vacuuming
Switch on the vacuum pump and open the high-pressure valve (B) on the pressure gauge manifold.
Step 3. Preparing the injector
Keep the low-pressure valve (A) and the injector valve (C) closed. Unscrew the oil injector cap and pour in the required amount of oil — usually 30–60 ml (depending on the specifications). Screw the cap back on tightly.
(Note: the original instructions often specify 1–2 ounces, which refers to the volume given in millilitres).
Step 4. Filling the system with oil
When the vacuum level reaches 740 mm Hg (almost a full vacuum), open the oil injector valve (C). The pump will continue to run, and due to the pressure difference, the compressor oil will automatically be drawn into the system. If a larger volume is required, repeat the procedure.
Step 5. Final vacuuming
Once the compressor oil has entered the air conditioning system, do not rush to charge it with refrigerant. You must continue the vacuuming process for at least another 45 minutes. This ensures the complete removal of moisture and air residues that may have entered during the operation of the injector.
Why is this important?
Using an oil injector helps keep the air conditioning system clean and ensures accurate dosing of compressor oil. Remember that an excess of compressor oil is just as harmful as a shortage, as it reduces cooling efficiency and increases the load on the air conditioning compressor.
Do you have any questions about choosing compressor oil or equipment? Please contact our specialists for advice on the following numbers:
+38(044) 492-04-20; +38(067) 440-55-92; +38(050) 312-49-09
ukravtoterm@gmail.com
+38 (044) 492-04-20
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