Remove grease and scale in the cooling system

AR20.00-B-1030XB

Remove grease and scale in the cooling system

12.02.16

Degrease

Danger!

Risk of accidents due to vehicle moving when the engine is started.Risk of injuries by pinching or suffer burns when working while the engine is being started or when the vehicle is moving

Assure vehicle against unintentional move. Utilize tight fitting and closed work clothes. Do not touch heated or running parts.

AS00.00-B-0005-01A

Danger!

Risk of injuries to skin and eyes, due to burns caused by steam or overheated coolant. Risk of poisoning by swallowing coolant

Open the cooling system only when the temperature is below 90 °C. Open the cap slowly and let the excessive pressure out. Coolant should not be kept in beverage bottles. Use gloves, appropriate clothes and protective glasses.

AS20.00-B-0001-01A

1

Remove the plug (3) located in the bottom part of the radiator and the plug (2) located on the oil cooler head and completely drain the cooling system.

For buses with space heating system, it will be necessary to open the valves in the engine compartment and the drain taps in the pipes next to the space heating radiator.

Discard the coolant in an environment safe way.

2

Remove the thermostats.

AR20.10-B-2460XB

3

Install two used thermostats, locked at full opening in order to ensure maximum flow circulates through the radiator.



Preparation of thermostat valves blocked at maximum opening

 The blocked valve permits full coolant circulation through the cooling system at any temperature.

WF58.50-B-2002-01A

*BE20.10-B-1002-02B

4

Install the drain plug.

5

Open the coolant filler neck cap (1), and fill the cooling system with degreasing solution.

The cooling system degreasing jobs are recommended when the coolant is contaminated with engine oil

Mix fresh water and 5% degreasing product (50g degreasing product, for every 950 gram water).

*BR00.45-B-1003-04A

Do not use caustic soda (sodium hydroxide) or any other strongly alkaline product. These products attack aluminum components of the cooling system.

6

Run the engine at medium speed until reaching 80 oC temperature and keep it in this temperature for 20 minutes, cover the radiator if necessary.

7

Stop the engine and wait until the temperature drops to 50 oC.

8

Remove the bottom radiator hose or the plug (3) and the plug (2), completely drain the solution from the cooling system.

Ecologically discard the solution from the cooling system.

Repeat consecutively, twice the filling operation, engine running and draining, mentioned below.

9

Open cap (1) of the cooling system and fill immediately with fresh water

10

Run the engine during 5 minutes

11

With the engine at a temperature below 50 oC, remove the bottom hose or plug and completely drain the cooling system.

Ecologically discard the cooling system liquid.



Check:

12

Check for the need to descale/deoxidize.

Should it be necessary to descale/deoxidize, follow the operations below:

Descaling/ deoxidizing

13

Fill the cooling system with descaling solution.

When in normal operation, the engine tends to overheat, without apparent motive, it is recommended to descale and deoxidize the cooling system.

Solution made of water and citric acid, in a 10% proportion (100 cm3 of citric acid to each 900 grams of water).

*BR00.45-B-1004-04A

14

Run the engine at medium speed until reaching 80 oC temperature and keep it at this temperature during 10 minutes, approximately.

15

Stop the engine and wait until the temperature drops to 50 oC approximately.

16

Completely drain the solution from the cooling system

17

Rinse the cooling system at least three times, with fresh water and for each rinsing run the engine for 5 minutes.

18

Remove the thermostats locked at full opening or of permanent opening.

19

Install the thermostats.

AR20.10-B-2460XB

20

Install and tighten the drain plugs in case there are plugs, or install the lower hoses.

21

Fill with coolant.

Anticorrosive and antifreeze mix: 



Change the coolant

Bus

AP20.00-B-2080XA

Número

Denominação

Engine 457.9

BE20.10-B-1002-02B

Main valve

Maximum opening

of C

95

Minimum stroke

mm

8

Número

Denominação

Número de pedido

BR00.45-B-1003-04A

Degreasing

P3 AL 580 E

BR00.45-B-1004-04A

Deep cleaner

Citric acid