Inspect Cooling System For Leaks - AR20.00-P-1010MFD

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Engine 260, 282 in model 118, 177, 247

Shown on model 177 with engine 282

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
	Notes on coolant level		AH20.00-P-1142-01CW
	Preparatory tasks
1	Switch on ignition.
2	Set the heater to the maximum temperature.
3	Unscrew cap from the coolant expansion reservoir (1).	Unscrew the cap slowly and relieve overpressure. Otherwise, severe injuries may result.
4	Check coolant level and antifreeze content of coolant.	Coolant mixing ratio	*BF20.00-P-1001-04A
5	Tighten the tester cap on the coolant expansion reservoir (1).	Test cap	Fig 1
6	Connect the pressure pump to the tester cap.	Pressure pump	Fig 2
7	Apply test pressure to the coolant circuit.	Test pressure for pressure-testing the engine cooling system	*BE20.30-P-1005-01A
	Check
8	Check condition and coolant loss for all coolant carrying assembly parts and connections.	There is the possibility that the coolant can find its way over a defective cylinder head gasket into the combustion chamber or over a defective heat exchanger into the oil circuit. If coolant loss is detected: ↓ Check the component parts that carry coolant for inner leak tightness and replace them if necessary.
	Final activities
9	Reduce the test pressure in the coolant circuit via the pressure relief button on the pressure pump.	Pressure pump	Fig 2
10	Remove the pressure pump from the tester cap.	Pressure pump	Fig 2
11	Unscrew the tester cap on the coolant expansion reservoir (1).	Test cap	Fig 1
12	Switch off ignition.
13	Check coolant level.	Coolant mixing ratio	*BF20.00-P-1001-04A
14	Tighten cap on coolant expansion reservoir (1).

RADIATOR OR EXPANSION RESERVOIR CAP

Number	Designation			2-stage latch cover
BE20.30-P-1005-01A	Test pressure for pressure-testing the engine cooling system	Overpressure	bar	1, 4

COOLANT MIXING RATIO

Number	Designation				All engines, except engine 178 in model 190.381
BF20.00-P-1001-04A	Coolant mixing ratio	Antifreeze/water	Up to -25°C	%	-
			Up to -37°C	%	50/50
			As of -38°C	%	55/45
			Overview and specifications sheet		BB00.40-P-0310-01A
			References to sheet specification		BB00.40-P-0310ZZ

Fig 1: Identifying Test Cap (210 589 00 91 00)

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Pressure Pump (124 589 24 21 00)

Courtesy of MERCEDES-BENZ USA