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

MODEL 166 with ENGINE 157, 276, 278, 642, 651

MODEL 292 with ENGINE 157, 276, 278, 642

Shown on model 166.057

	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
	Notes on coolant level		AH20.00-P-1142-01CW
	Remove
1	Switch on ignition
2	Adjust heater to maximum heat output
3	Unscrew cap (1) on coolant expansion reservoir (2)
4	Check coolant level and antifreeze content coolant
		Model 166 with engine 157, 276, 278, 642, 651	AP20.30-P-2050GB
		Model 292 with engine 157, 276.8, 278, 642	AP20.30-P-2050C
		Coolant mixing ratio	*BF20.00-P-1001-04A
		If the antifreeze content in the coolant is too low. ↓ Refill with new coolant
		Model 292 with engine 157, 276.8, 278, 642	AP20.00-P-2082D
		Model 166 with engine 157, 276, 278, 642, 651	AP20.00-P-2080EW
5	Mount tester cap (3) at coolant expansion reservoir (2)	Test cap	Fig 2
6	Connect pressure pump (4) at tester cap (3)	Pressure pump	Fig 1
7	Apply a test pressure to the engine cooling system for 2 minutes	The specified test pressure must not be exceeded. Damage will occur otherwise on the cooling circuit. There should be no pressure loss within a period of 2 minutes.
		Model 166 with engine 157, 276, 278 1-stage cover latch Model 166 with engine 157, 276, 278 2-stage cap latch Model 166 with engine 642, 651 1-stage cover latch Model 166 with engine 642, 651 2-stage cap latch Model 292 with engine 157, 276, 278 1-stage latch cover Model 292 with engine 157, 276, 278 2-stage latch cover Model 292 with engine 642 1-stage latch cover Model 292 with engine 642 2-stage latch cover 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
	Install
9	Actuate pressure relief button on the pressure pump (4) and remove test pressure in cooling circuit
10	Detach pressure pump (4) from tester cap (3)
11	Unscrew on tester cap (3) at coolant expansion reservoir (2)
12	Switch off ignition
13	Check and correct coolant level
		Model 292 with engine 157, 276, 278, 642	AP20.30-P-2050C
		Model 166 with engine 157, 276, 278, 642, 651	AP20.30-P-2050GB
14	Screw cap (1) onto coolant expansion reservoir (2)

RADIATOR OR EXPANSION RESERVOIR CAP

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

COOLANT MIXING RATIO

Number	Designation				Engine all
BF20.00-P-1001-04A	Coolant mixing ratio	Antifreeze/water	Up to -37°C	%	50/50
			As of -38 °C	%	55/45
			Sheet		BB00.40-P-0310-01A
			Sheet		BB00.40-P-0325-00A
			Sheet		BB00.40-P-0326-00A

Fig 1: Identifying Pressure Pump (124 589 24 21 00)

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Test Cap (210 589 00 91 00)

Courtesy of MERCEDES-BENZ USA