2018 Mercedes-Benz Metris A/C Refrigerant & Oil Specifications

Quick Answer: 2018 Mercedes-Benz Metris A/C Specs

• Refrigerant Type: R-1234yf
• Refrigerant Charge: 25.4 oz (720g)
• PAG Oil Type: PAG 46
• PAG Oil Capacity (Total System): 4.7 oz (140ml)
• Low-Side Port Location: Near the driver's side firewall, behind the strut tower.
• High-Side Port Location: In front of the radiator support, near the hood latch.

Why R-1234yf Matters

The 2018 Mercedes-Benz Metris uses the newer R-1234yf refrigerant. This is a significant change from the R-134a used in older vehicles. The switch was mandated by the EPA due to R-1234yf's much lower global warming potential. Here's what that means for you:

• Cost: R-1234yf is considerably more expensive than R-134a, both per pound and for the equipment required to service it.
• Specialized Equipment: Servicing an R-1234yf system requires a dedicated recovery and recharge machine. Cross-contamination with R-134a systems and oils can cause severe damage.
• Flammability: R-1234yf is mildly flammable, which introduces new handling procedures and equipment design requirements.

Because of these factors, most DIY-ers are not equipped to service R-1234yf systems. You cannot use off-the-shelf R-134a recharge cans.

Recharge Procedure

Properly recharging an A/C system is about more than just adding refrigerant. The correct method is crucial for system longevity and cooling performance.

1. Recovery: Any existing refrigerant in the system must be recovered using a dedicated R-1234yf machine.
2. Evacuation: The system is then placed under a deep vacuum for at least 30-45 minutes. This boils off any moisture, which is the enemy of A/C systems. This is the most critical and often skipped step in DIY repairs.
3. Charge by Weight: The exact-specified weight of refrigerant (720g for the Metris) is weighed and injected into the system. Charging by pressure using can gauges is inaccurate and can lead to over or undercharging, causing poor performance and potential compressor damage.

Common A/C Problems for the Mercedes-Benz Metris

While generally reliable, the Metris can experience common A/C issues:

• Condenser Damage: Located at the front of the vehicle, the condenser is susceptible to damage from road debris. A leak here is a common cause for the A/C to stop blowing cold.
• Compressor Failure: The A/C compressor is the heart of the system. While not a widespread issue on the Metris, failure can occur due to low refrigerant/oil levels, internal wear, or clutch issues.
• Evaporator Leaks: The evaporator core, located deep within the dashboard, can develop small leaks over time. This is often a labor-intensive repair.

When to Call a Pro

Due to the specialized equipment and refrigerant involved, almost all A/C service on a 2018 Metris should be handled by a professional shop. If your A/C is not blowing cold, a certified technician will perform a leak test and diagnose the root cause before attempting a recharge.

EPA Disclaimer: To legally purchase and handle refrigerants in the United States, you must be certified under EPA Section 609. Always wear safety glasses and gloves when working near the A/C system.

Find a certified A/C shop on Repairius.