Remove grease and scale in the cooling system · ar2000b1030b · Mercedes-Benz WIS

AR20.00-B-1030B

Remove grease and scale in the cooling system

08.01.2020

Engine

904.9, 906.9, 924.9, 926.9 in model 368.0/1, 384.06/07, 634.0, 685.282/284/289/290, 979.2

Remove grease and scale in the cooling system

1	Equalizing tank cap
2	Engine block drain plug

B20.00-0014-01

B20.00-0030-01

3	Drain plug on the cooler
4	Thermostatic valve

B20.00-0011-01

B20.00-0010-01

	Degrease
 Warning	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 pressure. Do not pour coolant into beverage containers. Wear protective gloves, protective clothing and safety glasses.	AS20.00-Z-0001-01A
1	Remove the equalizing tank cap (1)
2	Remove the plugs from the engine block (2) and cooler(3) and drain the coolant
	Drain/fill in coolant	.	AP20.00-B-2080-01B
		 If the vehicle is equipped with heating, actuate the command to the open position.
		 Install the plugs on the engine block and cooler, after completely draining the coolant.
		 Dispose of the coolant in an eco-friendly manner.
3	Remove the original thermostatic valve (4) and install a blocked thermostatic valve in the maximum opening position
	Blocked coolant thermostat valve for cleaning	.	WF58.50-B-2002-01A
		Remove/install coolant thermostat.	AR20.10-B-2460XA
		 The blocked valve is required to close the short-circuit passage and ensure total flow. The blocked valve allows full circulation of the fluid through the cooling system at any temperature.
		Main valve	*BE20.10-B-1002-02B
4	Fill up the cooling system with a degreasing solution	 Do not use caustic soda (sodium hydroxide) or another very alkaline product, because these products attack the aluminum parts of the cooling system.
		 Degreasing the cooling system is recommended when the coolant is contaminated with lubricating oil
		 Degreasing solution: Clean water and 5% of the degreasing product (50 g product per liter of water).
		Degreasing agent	*BR00.45-Z-1087-04A
 Warning	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
5	Run the engine at medium speed until it reaches the temperature of 80 °C, and keep it at this temperature for 20 minutes	 If necessary, cover the cooler to control the desired temperature.
6	Remove the plugs from the engine block (2) and the cooler (3) and drain the solution
	Drain/fill in coolant	.	AP20.00-B-2080-01B
		 Before draining the solution, stop the engine and wait until the engine temperature cools down to 50 °C. After completely draining the solution, install the drain plugs.
		 Dispose of the solution in an eco-friendly manner.
7	Immediately fill up the cooling system with clean water and run the engine for 5 minutes	 Stop the engine and wait until the temperature cools down to 50 °C. Drain the system, fill with clean water again and tun the engine for additional 5 minutes.
8	Stop the engine and completely drain the cooling system
	Drain/fill in coolant	.	AP20.00-B-2080-01B
		 Drain the cooling system when the coolant temperature is below 50 °C.
	Carry out the descaling and deoxidizing
9	Fill up the system with a descaling/deoxidizing solution	 When, under normal operating conditions, the engine shows a overheating trend without apparent reasons, descaling and deoxidizing the cooling system is advisable.
		 Descaling solution: clear water with 10% of citric acid (100 ml of citric acid per 1 liter of water).
		Citric acid powder (0.5 kg)	*BR00.45-Z-1070-04A
10	Run the engine at medium speed until it reaches the temperature of 80 °C, and keep it running at this temperature for 10 minutes	 If necessary, cover the cooler to control the desired temperature.
11	Remove the plugs from the engine block (2) and the cooler (3) and drain the solution
	Drain/fill in coolant	.	AP20.00-B-2080-01B
		 Before draining the solution, stop the engine and wait until the engine temperature cools down to 50 °C. After completely draining the solution, install the drain plugs.
		 Dispose of the solution in an eco-friendly manner.
12	Fill up the cooling system with clean water and run the engine for 5 minutes	 Stop the engine, wait until the temperature cools down to 50 °C and drain the system.
		 Repeat this operation three times.
13	Check the operation of the thermostatic valve (4)	Check coolant thermostat .	AR20.10-B-2455XA
14	Install the original thermostatic valve (4)	Remove/install coolant thermostat .	AR20.10-B-2460XA
		 Remove the blocked thermostat.
15	Fill the cooling system
Topical note	Notes on coolant		AH20.00-N-2080-01A
	Replace coolant	.	AP20.00-B-2080XA

Coolant thermostat

Number	Designation			Engines 902.9, 904.9, 906.9	Engines 924.9, 926.9
BE20.10-B-1002-02B	Main valve	Maximum opening	o C	95	95
		Minimum stroke	mm	8	8

Repair materials

Number	Designation	Order number
BR00.45-Z-1070-04A	Citric acid powder (0.5 kg)	A 000 989 10 25
BR00.45-Z-1087-04A	Degreasing agent	P3 AL 580 E

Referenced documents

ah2000n208001a Notes on coolant
ap2000b208001b Drain/fill in coolant
ap2000b2080xa Replace coolant
ar2010b2455xa Check coolant thermostat
ar2010b2460xa Remove/install coolant thermostat
as0000z000501a 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.
as2000z000101a Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.
wf5850b200201a Blocked coolant thermostat valve for cleaning