Remove/Install Coolant Thermostat - AR20.10-P-2461SVZ

Engine 279 in model 223

Fig 1: Coolant Thermostat Components Location - Model 223 With Engine 279

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 avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
Notice	Information on preventing damage to electronic components due to electrostatic discharge		AH54.00-P-0001-01A
	Remove/install
1	Remove engine cover.		AR01.10-P-2405SVZ
2	Drain off coolant.		AR20.00-P-1142SVZ
3	Remove left and right air intake lines (11).	Dismantling tool	Fig 2
4	Remove coolant pipe (1).	Replace O-ring (2). Screw/bolt, coolant pipe to coolant thermostat	*BA20.10-P-1005-01H
		Hose clamp pliers	Fig 3
		Assembly tool	Fig 4
5	Disconnect electrical connector at coolant temperature sensor (B11/4).
6	Remove vacuum line (3) from air shutoff valve (5).	Hose clamp pliers	Fig 3
7	Remove hose (4) from air shutoff valve (5).
8	Release screw clamp (12) at coolant hose (13).
9	Unscrew screws (7, 8) and remove coolant thermostat (6) upward.	Clean sealing surfaces, replace O-ring (9) and seal (10). Screw/bolt, coolant thermostat to cylinder head	*BA20.10-P-1004-01H
		Assembly cleaner	*BR00.45-Z-1028-04A
		Assembly tool	Fig 4
10	Install in the reverse order.