2019 Mercedes-Benz Metris A/C Refrigerant & Oil

Quick Answer

• Refrigerant Type: R-1234yf
• Full System Charge: 700 grams (24.7 oz)
• PAG Oil Type: PAG 46
• PAG Oil Amount: 130 ml (4.4 oz)
• Low-Side Service Port: On the accumulator/dryer, usually located towards the passenger side, near the firewall.
• High-Side Service Port: On the refrigerant line, typically near the condenser in front of the vehicle, or on a line coming off the compressor.

Why R-1234yf Matters

For your 2019 Mercedes-Benz Metris, the A/C system uses R-1234yf refrigerant. This is a significant change from the older R-134a refrigerant, primarily driven by environmental regulations. The European Union mandated the use of refrigerants with a lower Global Warming Potential (GWP) for all new vehicles produced after 2017, and R-1234yf fits this requirement. While R-134a has a GWP of 1430, R-1234yf has a GWP of just 4.

From a practical standpoint, this means a few things for Metris owners. Firstly, R-1234yf is considerably more expensive than R-134a. Expect to pay more for any A/C service involving refrigerant. Secondly, due to its flammability (a mild flammability, but still classified as such), specialized equipment is required for its recovery and recharging. This means that not all shops are equipped to service R-1234yf systems. Any technician working on R-1234yf systems should be properly trained and certified (EPA 609 certification is a must for all refrigerants, but additional R-1234yf specific training is highly recommended).

Recharge Procedure Cautions

Recharging an R-1234yf A/C system is not a DIY task and should never be attempted without proper training and equipment. It's crucial to understand that simply adding refrigerant based on pressure readings is an inaccurate and potentially damaging method. The only correct way to charge an A/C system, especially one using R-1234yf, is by weight using a dedicated A/C service machine.

The procedure generally involves:

1. Recovery: The old refrigerant (and any contaminants) is safely recovered from the system.
2. Vacuum (Evacuation): A vacuum pump is used to evacuate the system, removing any air and moisture. This is a critical step, as moisture in the system can lead to corrosion and component failure.
3. Leak Test: While under vacuum, the system is tested for leaks. It's pointless to recharge a leaky system.
4. Recharge by Weight: The precise amount of new R-1234yf refrigerant and PAG oil, as specified by the manufacturer, is charged into the system using a specialized A/C machine. The machine ensures the correct weight of refrigerant is added.

Never mix R-1234yf with R-134a or any other refrigerant. This can lead to system damage and is illegal.

Common A/C Problems for This Vehicle

While the Mercedes-Benz Metris is generally a reliable vehicle, A/C issues can arise. Some common problems observed across many vehicles, and potentially for the Metris, include:

• Compressor Failures: The A/C compressor is the heart of the system. Failures can be due to lack of lubrication (low refrigerant/oil), internal wear, or electrical issues. Symptoms include no cold air, a noisy compressor, or the compressor not engaging.
• Condenser Issues: The condenser, located at the front of the vehicle, can be damaged by road debris, leading to leaks. It can also become clogged with dirt and debris, reducing its efficiency.
• Evaporator Leaks: The evaporator, located inside the dashboard, can develop leaks. These are often difficult and costly to repair due to the labor involved in accessing the component. A common sign is a sweet, musty odor in the cabin.
• Blend Door Actuator Problems: While not a refrigerant issue, a faulty blend door actuator can prevent cold air from reaching the cabin, mimicking an A/C problem.

When to Call a Pro

If your 2019 Mercedes-Benz Metris A/C system isn't blowing cold, or if you notice any unusual noises or odors, it's best to consult a professional. Given the complexities and specific requirements of R-1234yf systems, attempting repairs yourself can be dangerous and costly. A certified HVAC technician will have the specialized tools and knowledge to accurately diagnose and repair the issue, ensuring your system operates efficiently and safely.

Safety Disclaimer: Working with automotive refrigerants requires specialized training, tools, and adherence to environmental regulations. Improper handling can lead to personal injury, damage to the vehicle, and harm to the environment. Always consult a qualified professional for A/C system service. Technicians must be EPA 609 certified to work with automotive refrigerants.

Find a certified A/C shop on Repairius.