Inspect Cooling System For Leaks - AR20.00-S-1010E

Model 447 with engine 274, 622, 651 

Model 448 with engine 274 

	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
	Remove
1	Remove lower engine compartment lining.		AR61.20-S-1105E
	Check
2	Set heater control to max. output.
3	Switch auxiliary heating to max. output.	Model 447 with code H12 (Auxiliary water heater) Model 447 with code H13 (Additional heat exchanger at the rear) Model 448
4	Open coolant expansion reservoir.	Turn cap on coolant expansion reservoir counterclockwise through half a revolution, release overpressure, and then remove cap.
5	Check coolant level.
	Service Information: Information on using coolant		SI20.00-Z-0017A
	Engine cooling system - inspecting fluid level, adjusting to correct level	If coolant level incorrect ↓ Correct coolant level.	AP20.00-S-2011E
6	Install tester cap on coolant expansion reservoir.	Test cap	Fig 1
7	Install pressure pump on tester cap.	Pressure pump	Fig 2
		Test cap	Fig 1
8	Apply test pressure to engine cooling system.	Test pressure	*BE20.30-Z-1004-01KOB
9	Check coolant hoses and their connections for damage and coolant loss.	In case of damage or coolant loss: ↓ Perform suitable repair measures. After obtaining special order.
10	Actuate pressure relief button on pressure pump and reduce test pressure in engine cooling system.	Pressure pump	Fig 2
11	Remove pressure pump from tester cap.	Pressure pump	Fig 2
		Test cap	Fig 1
12	Unscrew tester cap.	Test cap	Fig 1
13	Screw cap onto coolant expansion reservoir.
	Install
14	Install lower engine compartment lining.		AR61.20-S-1105E

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