First, chemical cleaning method to remove scale, commonly used simple chemical cleaning method. If you use alkali or acid aqueous solution, dissolve or soak the scale, make it fall off and clear. Its cleaning liquid formula is: (1) 2.5% concentration of dilute hydrochloric acid. (2) 6% concentration of caustic soda solution. (3) 2 to 3% concentration of soda solution. (4) 10% concentration of acetic acid. (5) 5% concentration of nitric acid. The first three are highly corrosive and can be used for corrosion-resistant cast iron parts, while the latter two are preferred only for aluminum alloy parts. This is practical experience. Since the water jacket is often greasy, 2 to 3% of kerosene may be added to the above cleaning solution. Second, the cleaning steps (1) exhausted the original cooling water, remove the thermostat, and then the cleaning fluid into the tank. (2) Start the engine, run at medium speed for 5lO minutes, stop for 8 to 12 hours, allow the cleaning solution to fully soak the scale. (3) start the engine to change the throttle position, so that the engine speed ups and downs, the use of water in the cooling system impact, to promote the scale off, suspended in the cleaning fluid, repeated several times and then stop and immediately release the cleaning fluid. (4) Fill up with clean soft water, start the engine and let it run for a few minutes at low speed. Release it for 2 to 3 times. After cleaning, replace the thermostat.
