Inspect cooling system for leaks - AR20.00-P-1010GQ

MODEL 166 with ENGINE 157 

MODEL 166 with ENGINE 276 

MODEL 166 with ENGINE 278 

MODEL 166 with ENGINE 642 

MODEL 166 with ENGINE 651 

Shown on model 166.057 

Fig 1: Inspecting Cooling System For Leaks - Shown On Model 166.057

Courtesy of MERCEDES-BENZ USA

	Remove
	Risk of injury  caused by fingers being jammed or pinched when removing, installing or aligning hoods, doors, trunk lid/rear-end door or sliding roof.	No parts of the body or limbs should be within the operating area when the components are moving.	AS00.00-Z-0011-01A
	Risk of injury  to skin and eyes suffering scalding from contact with hot coolant spray. 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
1	Switch on ignition
2	Adjust heater to maximum heat output
3	Unscrew cap (1) from coolant expansion reservoir (2)	Unscrew cap (1) slowly and relieve overpressure.
4	Check coolant level and antifreeze content coolant	If the antifreeze content of coolant is too low, either antifreeze protection must be added or the coolant must be replaced.
		Coolant mixing ratio	*BF20.00-P-1001-04A
5	Screw tester cap (3) onto coolant expansion reservoir (2)	Test cap	Fig 3
6	Connect pressure pump (4) at tester cap (3)	Pressure pump	Fig 2
7	Apply test pressure to cooling system	The specified test pressure must not be exceeded. Damage can occur to the cooling system otherwise.
		ENGINE 157, 276, 278, 642, 651 in MODEL 166 2-stage cover latch ENGINE 157, 276, 278, 642, 651 in MODEL 166 Cap	*BE20.30-P-1005-01A
	Check
8	Perform visual inspection on coolant carrying components	Check condition and coolant loss for all coolant carrying components and connections. The coolant carrying components should be checked for inner leak tightness if there is no external coolant loss. There is the possibility, for example, that coolant can find its way over a defective cylinder head gasket into the combustion chamber or over a defective water heat exchanger into the oil circuits. Check condition and seating of the Henn coupling. Replace if necessary. ↓ See "Open and close Henn coupling".
			AR09.41-P-1311-01AL
	Install
9	Relieve test pressure in cooling system	To do this actuate pressure relief button on the pressure pump (4)
10	Detach pressure pump (4) from tester cap (3)
11	Unscrew tester cap (3) on coolant expansion reservoir (2)
12	Switch off ignition
13	Check coolant level and antifreeze content coolant
	Notes on coolant level		AH20.00-P-1142-01CW
14	Screw cap onto coolant expansion reservoir (2)

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

Courtesy of MERCEDES-BENZ USA

Fig 3: Identifying Test Cap (210 589 00 91 00)

Courtesy of MERCEDES-BENZ USA