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

Engine 139 in model 118, 177, 247 

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
	Risk of injury  . Skin or eye injuries may result when handling hot or glowing objects.	Wear protective gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
	Risk of injury  caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
Notice	Notes on coolant		AH20.00-P-2080-01KOA
	Notes on coolant level		AH20.00-P-1142-01CW
	Remove
1	Remove upper engine cover.	If leaks occur in engine cooling system.
			AP01.10-P-2405-01K
2	Remove bottom engine compartment lining.	If leaks occur in engine cooling system.	AR61.20-P-1105MFR
3	Remove cap from coolant expansion reservoir (1).
	Check
4	Check antifreeze content of coolant.	Cooling system If antifreeze content is too low, ↓ Replace coolant.	*BF20.00-P-1001-06J
			AR09.41-P-6834MFG
5	Check coolant level
			AP20.30-P-2050T
6	Attach tester cap (2) to coolant expansion reservoir (1).	Test cap	Fig 1
7	Connect pressure pump (3) to tester cap (2).	Pressure pump	Fig 2
8	Apply a test pressure to the engine cooling system for 2 minutes.	Do not exceed the specified test pressure. Damage will occur otherwise to the engine cooling system There should be no pressure loss within a period of 2 minutes. Test pressure for pressure-testing the engine cooling system	*BE20.30-P-1005-01A
9	Check condition of all coolant carrying component parts and connections and check for leak tightness.	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 coolant-carrying components for inner leaktightness, replace if necessary.
	Install
10	Reduce test pressure in coolant circuit via pressure release button at pressure pump (3).	Pressure pump	Fig 2
11	Remove the pressure pump (3) from the tester cap (2).	Pressure pump	Fig 2
12	Remove tester cap (2) on coolant expansion reservoir (1).	Test cap	Fig 1
13	Check coolant level.
			AP20.30-P-2050T
		Cooling system	*BF20.00-P-1001-06J
14	Attach cap to the coolant expansion reservoir (1).
15	Install lower engine compartment lining.	If leaks were present in engine cooling system.	AR61.20-P-1105MFR
16	Install upper engine cover.	If leaks were present in engine cooling system.
			AP01.10-P-2405-01K

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

COOLING SYSTEM

Number	Designation				Engine 139 in model 118, 177, 247
BF20.00-P-1001-06J	Cooling system	Workshop replacement amount	Main circuit	Liter	11, 6
			Low-temperature circuit 1	Liter	2, 6
			Low-temperature circuit 2	Liter	-
		Antifreeze/water	to -37°C	%	50/50
			as from -38°C	%	55/45
			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