Remove, install coolant thermostat housing - AR20.10-P-2710M

ENGINE 275 in MODEL 215, 216, 220, 221, 230 

ENGINE 285 in MODEL 240 

Fig 1: Identifying Coolant Thermostat Housing Remove/Install Components - Shown On Model 220

Courtesy of MERCEDES-BENZ USA

Shown on MODEL 220 

	Remove/install
1	Drain coolant at radiator		AR20.00-P-1142H
2	Remove front engine cover	ENGINE 275.950 in MODEL 215.376, 220.176 ENGINE 275.951 in MODEL 230.476 ENGINE 275.953 in MODEL 216.376, 221.176 ENGINE 275.954 in MODEL 230.477 ENGINE 285 in MODEL 240	AR01.10-P-2405LA
		ENGINE 275.980 in MODEL 215.379, 220.179 ENGINE 275.981/983 in MODEL 230.479 ENGINE 275.982 in MODEL 216.379, 221.179	AR01.10-P-2405IM
3	Detach coolant line (1) and place to the side	Replace O-ring (2).
		Bolt, coolant line to housing for coolant thermostat	*BA20.10-P-1005-01AE
		Bolt, coolant line to cylinder head	*BA20.10-P-1006-01AE
4	Disconnect electrical connection at coolant temperature sensor (B11/4)
5	Detach air line (3) and hose (4) from air shutoff valve (5)
6	Detach coolant hose of coolant pump at coolant thermostat housing (6)
7	Check coolant hose for coolant pump and hose clamp for damage; replace if required.
8	Remove screw/bolts (7, 8) and remove coolant thermostat housing (6) upwards	Replace O-ring (9) and seal (10).
		Bolt, coolant thermostat housing to cylinder head	*BA20.10-P-1007-01AE
	Clean
9	Clean sealing surfaces on coolant thermostat housing (6) and cylinder head
10	Install in the reverse order
	Check
11	Check engine cooling system for leaktightness	ENGINE 275 (except 275.953/982) in MODEL 215, 220, 230 ENGINE 285 in MODEL 240	AR20.00-P-1010HA
		ENGINE 275 in MODEL 216, 221	AR20.00-P-1010SX