Remove/install heat exchanger - AR83.20-P-1100MCU

MODEL 451.3/4 (except 451.39/49) 

Fig 1: Identifying Heat Exchanger Remove/Install Components

Courtesy of MERCEDES-BENZ USA

	Removing
1	Drain coolant	Engine 132.9	AR20.00-P-1142MCC
		Engine 660.9	AR20.00-P-1142MCD
2	Remove foot support on passenger side	Only left-hand drive vehicles	AR68.30-P-1340MCC
3	Remove screw/bolt (2) and remove cover (1)
4	Use rag (7) to protect battery and battery recess against escaping coolant
5	Release clamps (4) at coolant lines (3) and detach
6	Pull coolant lines (3) out of heater heat exchanger (5)	Make sure no coolant runs over the battery or into the battery recess. Otherwise damage might be caused to on-board electrical system, battery or body.
7	Pull heater heat exchanger (5) out of the heater/air conditioner housing and put down	Make sure no coolant runs over the battery or into the battery recess. Otherwise damage might be caused to on-board electrical system, battery or body.
	Install
8	Insert heater heat exchanger (5) into the heater/air conditioner housing
9	Position coolant lines (3) on heater heat exchanger (5) and secure in place using clamps (4)	Replace seals (6).
10	Top up with coolant and check cooling system in area of heater heat exchanger (5) and coolant lines (3) for signs of leaks		AR20.00-P-1142MCU
11	Insert cover (1) into heater/air conditioner housing in the marked areas (arrows) and tighten bolt (2)
12	Remove rag (7)
13	Install foot support on passenger side		AR68.30-P-1340MCC