How to Check and Maintain Coolant Level in Your Mercedes-Benz R107

How to Check and Maintain Coolant Level in Your Mercedes-Benz R107

Maintaining the coolant level is essential for preventing overheating and ensuring the engine runs efficiently in your Mercedes-Benz R107. Below is a step-by-step guide on how to check, refill, and maintain the coolant system properly.


Checking the Coolant Level

📌 Important: Always check coolant when the engine is cold to avoid burns from hot steam or fluid.

Step 1: Locate the Coolant Reservoir

✅ The coolant expansion tank is separate from the radiator.
✅ Ensure the vehicle is parked on level ground before checking.

Step 2: Check the Coolant Level

  1. Coolant reservoir cap
  2. Marking for coolant level
  • When the coolant is cold → It should reach the marked level on the reservoir.
  • When the coolant is hot → It should be approximately 2 cm (0.8 in) above the mark due to expansion.

🚨 If the coolant level is low, you must add coolant immediately to prevent overheating.


How to Add Coolant

📌 Use the Correct Coolant Mixture:

  • Always use a 50/50 mixture of water and Mercedes-Benz (MB) anticorrosion/antifreeze coolant.
  • This ensures optimal engine cooling and protection against corrosion and freezing.

PEAK OET Extended Life Blue 50/50 Prediluted Antifreeze/Coolant for European Vehicles, 1 Gal.

Step 1: Open the Coolant Reservoir Carefully

🚨 Warning:

  • If the engine is above 90°C (194°F), DO NOT remove the cap!
  • If you see steam or leaking coolant, wait for the engine to cool down completely.

Step 2: Relieve Pressure Before Fully Opening

✅ Using a rag, turn the cap slowly to the first notch—this allows pressure to escape.
✅ Once all excess pressure is released, carefully remove the cap.

Step 3: Add Coolant

✅ Pour the 50/50 coolant mix slowly into the reservoir until it reaches the correct level.
✅ Securely tighten the cap to prevent leaks.


Coolant Drain and Replacement

🔧 Coolant Drain Locations:

  • Engine Drain Plugs: Located on both the right and left side of the engine.
  • Radiator Drain Plug: Located at the bottom of the radiator.

When to Replace Coolant:
✅ Follow the manufacturer’s recommended coolant change intervals.
✅ If the coolant appears dirty or rust-colored, flush and replace it immediately.


Coolant System Safety Warnings

🚨 Never open the coolant reservoir when the engine is hot—this can result in serious burns from steam and hot fluid.
🚨 Always dispose of old coolant properly—it is toxic to humans and animals.
🚨 Use only recommended Mercedes-Benz coolant—mixing different brands may cause engine damage.

PEAK OET Extended Life Blue 50/50 Prediluted Antifreeze/Coolant for European Vehicles, 1 Gal.


Final Tips for Coolant System Maintenance

✅ Regularly check the coolant level to prevent overheating.
✅ Inspect for leaks under the vehicle or around hoses and the radiator.
✅ Monitor engine temperature—if the temperature gauge rises abnormally, check the coolant system immediately.

By following these simple steps, you can keep your Mercedes-Benz R107 running cool and performing optimally! 🚗❄️