Remove/Install Coolant Lines - AR20.20-P-7440GQC

Engine 276.8 in model 166, 251, 292 

Fig 1: Coolant Lines Components Location - Engine 276.8 In Model 166

Courtesy of MERCEDES-BENZ USA

Shown on model 251 

Courtesy of MERCEDES-BENZ USA

	Risk of injury  caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
	Risk of death  when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)	Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.	AS00.00-Z-0035-01A
	General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system		AH00.00-Z-0300-01A
	Notes on battery		AH54.10-P-0001-01A
	Remove/install
1	Perform enable for the high voltage on-board electrical system	Engine 276.8 in model 166.063 For removal of the left coolant feed line (1L).	AR54.10-P-1150GQA
2	Drain off coolant	Engine 276.8 in model 166	AR20.00-P-1142GQ
		Engine 276.8 in model 251	AR20.00-P-1142GZC
3	Remove left-hand air filter housing	For removal of the left coolant feed line (1L) and the left coolant return line (2L).	AR09.10-P-1150GQC
4	Remove right air filter housing	For removal of the right coolant feed line (1R) and the right coolant return line (2R).	AR09.10-P-1150GQC
5	Remove windshield wiper system	Engine 276.8 in model 251 For removal of the left coolant feed line (1L) and the right coolant return line (1R).	AR82.30-P-6400RT
6	Remove left catalytic converter	Engine 276.8 in model 251 For removal of the left coolant feed line (1L).	AR49.10-P-5500GQC
7	Remove right catalytic converter	Engine 276.8 in model 251 When removing the right coolant feed line (1R).	AR49.10-P-5500GQC
8	Detach charge air cooler with attached lines and coolant hoses and place to one side	When removing the left coolant return line (2L).	AR09.41-P-6819GQC
9	Unclip vacuum hose of the ATL on the right coolant return line (2R)	When removing the right coolant return line (2R).
10	Detach bracket of right coolant return line (2R) on low temperature expansion reservoir carrier	When removing the right coolant return line (2R).
11	Detach bracket for left coolant return line (2L) on coolant thermostat, left ATL and oil filter housing	When removing the left coolant return line (2L)
12	Detach right oil line return line (2R) and left oil line return line (2L) at connection for coolant hose (3)	The coolant hose connection (3) is located for model 166 on the left cylinder head.
13	Remove heat shield over knock sensor	For removal of the left coolant feed line (1L).	AR15.12-P-2136GQ
		Engine 276.8 in model 166.063 For removal of the heat shield ensure that the electrical line to the electrical A/C compressor is not damaged. Otherwise in the case of damage the electrical line to the electrical A/C compressor must be replaced.
14	Detach heat shield (4)	When removing the left coolant return line (2L). Bolt, turbocharger shield bracket to cylinder head	*BA09.40-P-1012-01W
		Bolt/nut for shield attachment	*BA09.40-P-1011-01W
15	Detach heat shield (8)	When removing the right coolant return line (2R). Bolt, turbocharger shield bracket to cylinder head	*BA09.40-P-1012-01W
		Bolt/nut for shield attachment	*BA09.40-P-1011-01W
16	Remove heat shields (5, 6)	For removal of the left coolant feed line (1L). Bolt/nut for shield attachment	*BA09.40-P-1011-01W
		Bolt/nut for shield attachment	*BA09.40-P-1011-01W
17	Detach heat shield (7) over starter	When removing the right coolant feed line (1R). Bolt/nut for shield attachment	*BA09.40-P-1011-01W
18	Detach right coolant return line (2R) on right ATL, remove upwards and close off with stop plug	When removing the right coolant return line (2R). Replace sealing ring.
		Bolt, coolant feed/return line to turbocharger	*BA09.40-P-1008-01W
		Record plug	Fig 2
19	Detach left coolant return line (2L) on left ATL, remove upwards and close off with stop plug	When removing the left coolant return line (2L). Replace sealing ring.
		Bolt, coolant feed/return line to turbocharger	*BA09.40-P-1008-01W
		Record plug	Fig 2
20	Detach left coolant feed line (1L) on left ATL and on crankcase, remove upwards and close off with stop plug	For removal of the left coolant feed line (1L). Replace sealing ring.
		Bolt, coolant feed/return line to turbocharger	*BA09.40-P-1008-01W
		Bolt, coolant feed line to crankcase	*BA09.40-P-1009-01W
21	Install in the reverse order
	Risk of accident  from vehicle starting off by itself when engine running. Risk of injury  (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
22	Carry out engine test run, checking the engine for leaktightness and proper operation

Fig 2: Identifying Record Plug (129 589 00 91 00)

Courtesy of MERCEDES-BENZ USA