Testing cooling system cap - AR20.30-P-4300GZS (ML63 AMG)

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ENGINE 156 in MODEL 164, 251

Fig 1: Identifying Cooling System Cap, Adapter And Pressure Pump

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

	Checking
	Risk of injury caused by fingers being pinched or crushed when removing, installing or aligning hoods, doors, trunk lids, tailgates or sliding roof.	Keep body parts and limbs well clear of moving parts.	AS00.00-Z-0011-01A
	Risk of injury to skin and eyes caused by scalding from contact with hot coolant spray. Risk of poisoning caused by 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	All engines	AH20.00-N-2080-01A
1	Open engine hood	Model 164	AR88.40-P-1000GZ
		Model 251	AR88.40-P-1000RT
2	Screw down coolant system cap (1)	Rotate the cooling system cap (1) halfway through in the anti-clockwise direction and release the excess pressure. Then screw down cooling system cap (1).
3	Fix the adapter (2) to the pressure pump (3)	Pressure pump	Fig 3
		Adapter	Fig 2
4	Screw on cooling system cap (1) at adapter (2)	Adapter	Fig 2
5	Check pressure relief valve in cooling system cap (1)	Establish opening pressure of pressure relief valve by pumping and replace cooling system cap (1) if necessary.
		Cap code number	*BE20.30-P-1001-01A
		Pressure relief valve opens	*BE20.30-P-1004-01A
6	Check vacuum valve in cooling system cap (1)	Changeover the pressure pump (3) and determine the opening pressure of the vacuum valve by pumping. If necessary, replace the cooling system cap (1).
		Cap code number	*BE20.30-P-1001-01A
		Vacuum valve opens (reference value)	*BE20.30-P-1003-01A
7	Close coolant expansion reservoir using cooling system cap (1)
8	Close engine hood	Model 164	AR88.40-P-1000GZ
		Model 251	AR88.40-P-1000RT

CAP FOR RADIATOR OR EXPANSION RESERVOIR

Number	Designation			2-stage cap
BE20.30-P-1001-01A	Cap code number			140/200
BE20.30-P-1003-01A	Vacuum valve opens (reference value)		bar vacuum	0.1
BE20.30-P-1004-01A	Pressure relief valve opens	Stage 1	bar gage	1.4 ± 1
		Stage 1	Coolant temp.	≥ 130/134
		Stage 2	bar gage	2.0 ± 1
		Stage 2	Coolant temp.	≥ 137/143

Fig 2: Identifying Adapter (210 589 03 63 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Pressure Pump (124 589 24 21 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.