necessary, then rinse the radiator with clean water and dry it with air.
Provide adequate ventilation of the working area to avoid possible toxic effects of the cleaning spray.
To avoid damage to the radiator fins, do not use high air or water pressure.
Another method of cleaning the radiator is the use of steam or a steam cleaning device, if available. If the
foreign deposits are hardened, it may be necessary to apply solvents.
The scale deposit inside the radiator is a result of using hard, high mineral content water in the cooling system.
The effect of heat on the minerals in the water causes the formation of scale, or hard coating, on metal
surfaces within the radiator, thereby reducing the transfer of heat. Some hard water, instead of forming scale,
will produce a silt-like deposit which restricts the flow of water. This must be flushed out at least twice a year --
more often if necessary.
To remove the hardened scale, a direct chemical action is necessary. A flushing compound such as
salammoniac, at the specified rate of 1/4 pound per each gallon of radiator capacity, should be added to the
coolant water in the form of a dissolved solution while the engine is running. Operate the engine for at least
fifteen minutes, then drain and flush the system with clean water.
Other flushing compounds are commercially available and should be procured from a reliable source. Most
compounds attack metals and should not remain in the engine for more than a few minutes. A neutralizer
should be used in the cooling system immediately after a de-scaling solvent is used.
For extremely hard, stubborn coatings, such as lime scale, it may be necessary to use a stronger solution. The
corrosive action of a stronger solution will affect the thin metals of the radiator, thereby reducing its operating
life. A complete flushing and rinsing is mandatory and must be accomplished skillfully.
After the solvent and neutralizer have been used and the cooling system is flushed, completely drain the entire
system again and fill it with a recommended coolant (refer to Engine Coolant). After filling the cooling system,
inspect the radiator and engine for water leaks.
When draining or filling, the cooling system must be vented.