AR20.00-B-1030A | Remove grease and scale in the cooling system | 12.02.16 |
Cumbustion engine 372, 374, 376, 377 with Vehicle 382, 384, 386, 682, 688, 693, 694, 695
B20.00-0047-01
B20.00-0011-01
Represented in engine 374.9
1 Cooling system reservoir cover
Arrow Maximum level mark
3 Draining plug in the radiator
B18.20-0006-01
B20.00-0050-01
Arrow Radiator draining plug in the oil radiator
1 Draining plug in the engine block
Degrease | |||
Danger! | Risk of accidents due to the movement of the vehicle when the engine is actuated. Risk of injuries due to being caught or burned when intervening during the engine actuation or when the vehicle is in motion | Make sure that the vehicle will not accidentally move. Wear work clothes well closed and tight. Do not touch the heated or moving parts. | |
Danger! | Risk of explosion due to leak of natural gas or overheating of the compressed gas reservoir when you carry out services with natural gas vehicles. Risk of freezing of the members due to gas leaks or due to contact with components close to the valves when compressed gas reservoirs are being emptied. Risk of intoxication and asphyxia due to inhalation of natural gas | Eliminate the ignition sources. Wear heat protective gloves . Make sure that there is sufficient ventilation. | |
Danger! | Risk of injuries in the skin and eyes, due to burns caused by very heated coolant spills. Risk of poisoning due to coolant ingestion | Only open the coolant system in a temperature below 90 °C. Open slowly the cap and allow the pressure surplus to go out. Do not keep coolant in beverage recipients. Always wear protective gloves, clothes and goggles. | |
| Indications relative to coolants | ||
1 | Drain the cooling system | With the engine cold or at a temperature not to exceed 50°. If there is a heating system, previously put its control in the heating position and check if the stopcock is opened. | |
In the case of buses, the stopcocks located in the engine compartment and the draining taps in the tubes close to the heating radiator must be opened. | |||
Eliminate the coolant in an environment friendly manner. | |||
Engines 372.9, 376.9, 377.9. | |||
Engines 374.9. | |||
2 | Remove the thermostatic valve | ||
3 | Install the locked thermostatic valve | In the engines with 2 thermostatic valves lock only the side responsible for the closing of the short circuit way. | |
| Preparation of the thermostatic valves locked in the maximum opening | The locked valve enables the full circulation of the liquid through the cooling system at any temperature. | |
4 | Supply the cooling system with a degrease solution | Mix of clean water and 5% of a degrease product (50 g of degrease product for every 950 g of water). | |
Do not use caustic soda (sodium hydroxide) or other very alkaline product. Such products are bad for the cooling system aluminum components. | |||
5 | Actuate the engine and keep it at an intermediate rpm range until reaching a temperature of 80 °C and keeping it like this for 20 minutes | If necessary, cover the radiator. | |
6 | Shut the engine down and wait until the temperature reaches 50 °C | ||
7 | Drain the cooling system | Eliminate the coolant in an environmental friendly manner. | |
For engines 374.9 | |||
For the engines 372.9, 376.9, 377.9 | |||
8 | Supply immediately the cooling system with clean water | ||
9 | Actuate the engine and keep it operating for 5 minutes | ||
10 | Switch the engine off and drain the cooling system. | Wait until the temperature reaches 50 °C. | |
For engines 374.9 | |||
For the engines 372.9, 376.9, 377.9 | |||
Repeat the steps 8, 9 and 10 operations twice again. | |||
Eliminate the scales and rust | |||
11 | Supply the cooling system with a descale solution | De-scaling solution: Clean water and 10% of citric acid (100 cubic centimeters of citric acid for every 900 g of water). | |
12 | Actuate the engine and keep it at medium rpm until reaching a temperature of 80 °C keeping it like that for 10 minutes | If necessary, cover the radiator. | |
13 | Shut the engine down and wait until the temperature reaches 50 °C | ||
14 | Drain the cooling system | Eliminate the coolant in an environmental friendly manner. | |
For engines 374.9 | |||
For the engines 372.9, 376.9, 377.9 | |||
15 | Supply the cooling system with clean water, let the engine operate for 5 minutes and then shut it down | Do this three times. Each time the engine is switched off, wait for the temperature to reach 50 °C and drain the system. | |
16 | Remove the blocked thermostatic valve | ||
17 | Check the thermostatic valves | In the case of two valves engines, if one of the valves presents defect, replacing both is recommended, mainly in the case of high mileage engines. | |
18 | Install the thermostatic valves | ||
19 | Install and tighten the draining plugs, and if there are no plugs, install the lower hoses | ||
20 | Prepare the engine coolant | Currently used anti-corrosion and anti-freeze solution. | |
21 | Supply the cooling system | For engines 374.9 | |
For the engines 372.9, 376.9, 377.9 | |||
22 | Operate the engine and check if there are eventual leaks |
Coolant thermostat
Número | Denominação | Engine 374.905/907/908, 374.950/951/952, 374.953/978/979, 3749.985/986/987, 3749.988/989/990 Engine 374.976/977/992 from engine number 674.464 on | Engine 372.9, 376.90/93/94, 376.95/98/99 | |||
BE20.10-B-1002-02A | Main valve | Maximum opening | °C | 95 | 95 | |
Minimum stroke | mm | 8 | 8 | |||
Coolant thermostat
Número | Denominação | Engine 377.9 except for 377.987; | Engine 376.961/962/963, 376.964/967/972 | |||
BE20.10-B-1002-02A | Main valve | Maximum opening | °C | 95 | 95 | |
Minimum stroke | mm | 8 | 8 | |||
Coolant thermostat
Número | Denominação | Engine 374.991/993/996 Engine 374.976/977/992 up to engine 674464Engine 377.987 | Engine 372.924/926/927, 376.929 Engine 374.980/981/982, 374.984 Engine 376.919/922/923, 376.924/925/926, 376.927/968/969, 376.970/975/976, 376.977 | |||
BE20.10-B-1002-02A | Main valve | Maximum opening | °C | 95 | 94 | |
Minimum stroke | mm | 8 | 8 | |||
Produtos para reparos
Número | Denominação | Número de pedido |
BR00.45-B-1003-04A | Degreasing | P3 AL 580 E |
BR00.45-B-1004-04A | Deep cleaner | Citric acid |