Check Low-Temperature Circuit For Leaktightness - AR09.41-P-1011MSA

Engine 256.9 in model 213, 238, 257, 290 

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
Notice	Notes on coolant		AH20.00-P-2080-01KOA
	Notes on coolant level		AH20.00-P-1142-01CW
	Check
1	Remove cap (2) from expansion reservoir (1).
2	Check coolant level and antifreeze content of coolant.	Coolant mixing ratio	*BF20.00-P-1001-04A
3	Fit tester cap (3) on expansion reservoir (1).	Test cap	Fig 1
4	Connect pressure pump (4) to tester cap (3).	Pressure pump	Fig 2
5	Apply compressed air to the low-temperature circuit for 2 minutes.	Do not exceed the specified test pressure. Otherwise, damage occurs to low-temperature circuit. There should be no pressure drop within a period of 2 minutes. Test pressure for pressure-testing the engine cooling system	*BE20.30-P-1005-01A
6	Check all coolant-conducting component parts and connections of low-temperature circuit for condition and coolant loss, and replace if necessary.	In the event of pressure drop.
7	Relieve test pressure using valve of pressure pump (4).	Pressure pump	Fig 2
8	Remove pressure pump (4) from test connection (3).
9	Remove tester cap (3) from expansion reservoir (1).	Test cap	Fig 1
10	Check the coolant level and antifreeze content of the coolant and correct if necessary	Coolant mixing ratio	*BF20.00-P-1001-04A
11	Fit cap (2) on expansion reservoir (1).

RADIATOR OR EXPANSION RESERVOIR CAP

Number	Designation			Engine 100, 102, 103, 104, 110, 111, 112, 113, 114, 115, 116, 117, 119, 120, 121, 123, 127, 129, 130, 133, 137, 139, 152, 155, 156, 157, 159, 166, 180, 254, 256, 260, 264, 266, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 282, 285 2-stage latch cover Engine 601, 602, 603, 604, 605, 606, 607, 608, 611, 612, 613, 615, 616, 617, 621, 626, 628, 629, 640, 642, 646, 648, 651, 654, 656, 668 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