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

Engine 276.8 in model 172 

Engine 276.8 in model 231 

Fig 1: Coolant Lines Components Location - Engine 276.8 In Model 172 (Shown In Model 231)

Courtesy of MERCEDES-BENZ USA

Shown on engine 276.8 in model 231 

Courtesy of MERCEDES-BENZ USA

	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
	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
	Remove/install
1	Drain coolant from low-temperature circuit		AR09.41-P-6834RKA
2	Remove right air filter housing	For removal of the right coolant feed line (1R) and the right coolant return line (2R).
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-1150RKA
4	Detach charge air cooler at both charge air pipes and at throttle valve actuator and pull to the front	When removing the left coolant return line (2L).	AR09.41-P-6819RKA
5	Detach left coolant line return line (2L) and right coolant line return line (2R) at connection for coolant hose (3)	Engine 276.8 in model 231 up to model year 2016
6	Detach left coolant line return line (2L) at connection for coolant hose (3)	Engine 276.8 in model 172 Engine 276.8 in model 231 as of model year 2016 When removing the left coolant return line (2L).
7	Detach right coolant return line (2R) at distributor below the low-temperature circuit expansion reservoir	Engine 276.8 in model 172 Engine 276.8 in model 231 as of model year 2016 When removing the right coolant return line (2R).
8	Detach left coolant feed line (1L) on ATL	When removing the left coolant return line (2L).
9	Detach right coolant feed line (1R) on ATL	When removing the right coolant return line (2R).
10	Remove heat shields (4)	When removing the left coolant return line (2L).
		Bolt/nut for shield attachment	*BA09.40-P-1011-01W
		Bolt, turbocharger shield bracket to cylinder head	*BA09.40-P-1012-01W
11	Remove heat shield (6)	When removing the right coolant return line (2R).
		Bolt/nut for shield attachment	*BA09.40-P-1011-01W
		Bolt, turbocharger shield bracket to cylinder head	*BA09.40-P-1012-01W
12	Detach bracket for left coolant return line (2L) on ATL	When removing the left coolant return line (2L).
13	Detach bracket for right coolant return line (2R) on ATL	When removing the right coolant return line (2R).
14	Detach bracket for left coolant return line (2L) on oil filter housing and thermostat	When removing the left coolant return line (2L).
		Bolt for coolant line attachment	*BA09.40-P-1010-01W
15	Detach left coolant return line (2L) on ATL anc close off openings with suitable stop plugs	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
16	Detach right coolant return line (2R) on ATL and close off openings with suitable 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
17	Remove left coolant return line (2L)	When removing the left coolant return line (2L).
18	Remove right coolant return line (2R)	When removing the right coolant return line (2R).
19	Detach left coolant feed line (1L) on ATL and close off openings with suitable stop plugs	For removal of the left coolant feed line (1L).
		: Replace sealing ring.
		Bolt, coolant feed/return line to turbocharger	*BA09.40-P-1008-01W
		Record plug	Fig 2
20	Detach right coolant feed line (1R) on ATL anc close off openings with suitable stop plugs	When removing the right coolant feed line (1R).
		: Replace sealing ring.
		Bolt, coolant feed/return line to turbocharger	*BA09.40-P-1008-01W
		Record plug	Fig 2
21	Detach left coolant feed line (1L) on crankcase and close off openings with suitable stop plugs	For removal of the left coolant feed line (1L).
		: Replace sealing ring.
		Bolt, coolant feed line to crankcase	*BA09.40-P-1009-01W
		Record plug	Fig 2
22	Detach right coolant feed line (1R) on crankcase and close off openings with suitable stop plugs	When removing the right coolant feed line (1R).
		: Replace sealing ring.
		Bolt, coolant feed line to crankcase	*BA09.40-P-1009-01W
		Record plug	Fig 2
23	Detach bracket for left coolant feed line (1L) at cylinder head cover	Engine 276.8 in model 231 up to model year 2016 For removal of the left coolant feed line (1L).
24	Detach bracket for right coolant feed line (1R) at cylinder head cover	Engine 276.8 in model 231 up to model year 2016 When removing the right coolant feed line (1R).
25	Detach bracket for left coolant feed line (1L) at bracket for the heat shield on ATL	For removal of the left coolant feed line (1L).
26	Detach bracket for right coolant feed line (1R) at crash plate	When removing the right coolant feed line (1R).
27	Remove left cool coolant feed line (1L)	For removal of the left coolant feed line (1L).
28	Remove right coolant feed line (1R)	When removing the right coolant feed line (1R)
29	Install in the reverse order
30	Check low-temperature circuit for leak tightness		AR09.41-P-1010RKA
	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
31	Carry out engine test run, checking the engine for leak tightness and proper operation

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

Courtesy of MERCEDES-BENZ USA