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

Engine 176 in model 463 

as of model year 2019 

Engine 177, 264, 656 in model 463 

Shown on engine 656 in model 463.349 

Courtesy of MERCEDES-BENZ USA

Shown on engine 176 in model 463.260 

Fig 1: Main Circuit Coolant Expansion Reservoir Components Location - Engine 176 In Model 463 As Of Model Year 2019 And Engine 177 In Model 463 (Shown On Engine 176 In Model 463.260)

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
	Check
1.1	Check coolant level in area of coolant expansion reservoir joint (3) of coolant expansion reservoir (2).	Engine 264, 656 in model 463 If the coolant level is above the coolant expansion reservoir joint (3), ↓ Coolant level correct, check complete, no further operations steps necessary. If the coolant level is below the coolant expansion reservoir joint (3), ↓ check coolant level in coolant expansion reservoir (2), continue with operation step 2.
1.2	Check coolant level in light-dark boundary area of coolant expansion reservoir (2).	Engine 176 in model 463 as of model year 2019 Engine 177 in model 463 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	BB00.40-P-0310-01A
		After obtaining special order.
	Install
4	Seal coolant expansion reservoir (2) with cap (1).