Check main circuit coolant level - AP20.30-P-2050A

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ENGINE 178 in MODEL 190

Fig 1: Locating Coolant Expansion Reservoir Cap (Engine 178)

Courtesy of MERCEDES-BENZ USA

	Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.	Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers. Wear protective gloves, protective clothing and safety glasses.	AS20.00-Z-0001-01A
	Notes on coolant		AH20.00-N-2080-01A
	Preparatory activity
1	Open engine hood
	Open engine hood		AR88.40-P-1000RG
	Remove
2	Remove engine compartment paneling
	Check
3	Check coolant level in light-dark boundary area of coolant expansion reservoir (2)	For coolant expansion reservoirs (2) with transparent tank lower part. Coolant level below light-dark boundary: ↓ Coolant level incorrect, continue with operation step 4. Coolant level above light-dark boundary: ↓ Coolant level correct, continue with operation step 7.
	Remove
4	Unscrew cap (1) for coolant expansion reservoir (2)	If coolant level is incorrect.
	Check
5	Check coolant level	For an incorrect coolant level. The coolant level on a cold engine must reach up to the marking (arrow) in the coolant expansion reservoir (2). When the coolant is warm, about 1 cm (0.39 inch) above the marking (arrow). If coolant level is too low: ↓ Check coolant for leaktightness and check coolant for antifreeze content subject to separate repair order.
		Coolant specifications	Coolant (Specification 310.1). See https://bevo.mercedes-benz.com/index.php?language_id=1
		Anticorrosion/antifreeze agents (Specifications 325.0)	Anticorrosion/antifreeze agents (Specification 325.0). See https://bevo.mercedes-benz.com/index.php?language_id=1
		Coolant mixing ratio	*BF20.00-P-1001-04A
	Install
6	Seal coolant expansion reservoir (2) with cap (1)	For an incorrect coolant level.
7	Install engine compartment paneling
	Finishing activity
8	Close engine hood
	Close engine hood		AR88.40-P-1000RG

COOLANT MIXING RATIO

Number	Designation			ENGINE ALL
BF20.00-P-1001-04A	Coolant mixing ratio	Antifreeze/water	bis -37°C	50/50
		Antifreeze/water	bis -45°C	55/45
		Specifications		Coolant (Specification 310.1). See https://bevo.mercedes-benz.com/index.php?language_id=1