The cooling capacity of the air conditioning system gradually decreases - until it fails. Air conditioning servicing is therefore essential, as all car dealerships now know. However, the air conditioning service unit is also a system that requires maintenance, a fact that is often overlooked by many workshop operators. If the maintenance work recommended by the device manufacturer is neglected, the device suffers increased wear and tear. The consequences: Air conditioning systems are not sufficiently vacuumed or are filled incorrectly. Poorly maintained appliances also have a high risk of failure. If they are defective, a lot of revenue goes down the drain during the peak air conditioning season.
At least once a year, workshop operators should have their A/C service units serviced in accordance with the manufacturer's instructions. If you don't have a maintenance contract, more modern air conditioning service stations will remind you via their display: these stations have an internal counter that documents the amount of refrigerant extracted and then issues an alert when maintenance is due. And this should be adhered to.
In addition to the typical maintenance work - see below - the service technician will also check the software status and inspect the condition of the appliance.
During maintenance, the vacuum pump oil (depending on its condition) and the device's internal filter dryer are generally replaced. Experience has shown that Compressor oil can leak from the vehicle into the vacuum pump of the A/C service unit. These are often only small quantities, but the oil level in the unit rises with every A/C service. In addition, old and used oil leads to wear on the vacuum pump, the component of the A/C service unit that is subject to the highest stress. Its performance then decreases unnoticed. The vacuum level generated is no longer sufficient to completely extract the refrigerant and moisture from the vehicle's refrigerant circuit.
Humidity not only damages the air conditioning system, but also the air conditioning service unit. This is why it is also very important to change the appliance's internal filter dryer regularly. This is because it absorbs moisture and dirt in the extracted refrigerant - saturation increases with each recycling process. This measure also prevents solids from getting into the valve blocks, which inevitably leads to expensive repairs.
Newer air conditioning service units have scales for refrigerant and compressor oil which, depending on the manufacturer's specifications, must be checked during servicing and readjusted if necessary. This is because temperature fluctuations and hard impacts when maneuvering can cause the device's internal scales to become misaligned and provide incorrect values. Zeroing the scales in the device software is usually not enough to bring the measuring systems back into balance.
If the A/C service unit is working with incorrect values, the filling quantities will no longer match. The user is also unaware of this and unknowingly installs sources of error in the customer's vehicle, which can sooner or later lead to complaints or even consequential damage.
Another important topic in appliance maintenance is the leak test. For the best possible environmental protection during A/C servicing, modern A/C service units meet strict standards such as SAE J2788. With the leak test, however, the air conditioning professional not only meets the requirements for the best possible environmental protection. A leaking A/C service unit is also a burden on the workshop manager's wallet. This is because internal leaks are hardly noticeable in everyday workshop use. Especially if the appliance is only used irregularly or by different people.
Depending on the size of the leak, such unnoticed refrigerant losses can be quite expensive. What's more, the accuracy and tightness of the air conditioning service unit required for R1234yf can only be maintained with regular maintenance.
Conclusion: Maintenance of the air conditioning service unit is something for the specialist. They possess the model-specific inspection plan and know what to look out for and inspect. Keep this in mind, and nothing stands in the way of an uninterrupted air conditioning season.