Check Main Circuit Coolant Level - AP20.30-P-2050E

WARNING: This page is about a different car, the 2023 Mercedes-Benz GLC300, 2022 Mercedes-Benz GLC300, 2021 Mercedes-Benz GLC300, 2020 Mercedes-Benz GLC350e, and 2020 Mercedes-Benz GLC300. However, it is still accessible from the selected car via links, so may be relevant.

Engine 177, 264, 274, 276, 642, 651, 654, 656 in model 253

Shown on engine 274.9 in model 253.3

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 overpressure. Do not pour coolant into beverage containers. Wear protective gloves, protective clothing and safety glasses.	AS20.00-Z-0001-01A
Notice	Notes on coolant		AH20.00-P-2080-01KOA
	Check
1	Check coolant level in light-dark boundary area of coolant expansion reservoir (2).	If the coolant level is above the light-dark boundary, ↓ coolant level correct, check complete, no further operations steps necessary. If the coolant level is below the light-dark boundary, ↓ check coolant level in coolant expansion reservoir (2), continue with operation step 2.
	Remove
2	Unscrew the cap (1) of the coolant expansion reservoir (2).
	Check
3	Check coolant level.	With a cold engine, the coolant level must reach the marking (arrow) in the coolant expansion reservoir (2). When the coolant is warm: approx. 1 cm (0.39 inch) above the marking (arrow). If the coolant level is too low, ↓ Check Cooling system for leak tightness and coolant for antifreeze content.
		Coolant specifications After obtaining special order.	BB00.40-P-0310-01A
	Install
4	Seal coolant expansion reservoir (2) with cap (1).