AET 160 Ch. 21 (2023/2024) 100% Pass

AET 160 Ch. 21 (2023/2024) 100% Pass Cooling system problems Coolant level, Restricted Radiator, Stuck thermostat, Defective water pump, loose or missing Fan shroud, Frozen coolant, Defective cooling fan, Exhaust blockage, Inoperative EGR valve Thermostat stuck open Engine can overheat at freeway speeds, but not warm up as soon as it should in the city Corrosion bloom A white deposit that attaches to the tops of the tubes, the additives have been depleted Coolant change interval Every 3 years or 30,000 miles When is a coolant system flush required When a new thermostat or coolant pump is installed Coolant exchanger Many maintenance and repair facilities use these, it is a machine that exchanges the coolant for you without making a big mess Coolant test strips Three or more chemically treated pads attached to a long thin piece of plastic. They change colors to indicate the pH, additive condition, and freeze point Refractometer The best tool for measuring coolant concentration. An optical tester that measures how much light can be refracted by a liquid HOAT coolant (hybrid organic acid technology) A popular coolant used in a majority of new vehicles. It contains silicates at a lower level than IAT coolant Sodium Silicate An excellent aluminum protection additive, but too much can cause problems Cavitation When air bubbles form in the coolant and then collapse Air Lift An effective way to check for leaks and refill the cooling system. It ensures that the cooling system is purged of air Pressure tester Helpful for locating an internal or external leak Check for external leaks At the heater core, heater hoses, radiator hoses, thermostat housing, core plugs, radiator, or the hole on the water pump Bubble test A way to test for an internal leaks by looking for bubbles in the radiator when the engine is warm and under load When measuring the voltage of the coolant what is the limit before the system needs to be flushed 0.4 What is the name of the tester that compares the density of water and coolant Coolant density tester Which removes rust and scale, acid or base Why is there a small hole in some thermostats To bleed air from the system Thermoplastic seizure When coolant has migrated into the engine oil, it can seize the engine Block check test Another way to test for leakage of exhaust gases into the cooling system, Samples air in the radiator filler neck and is used with the engine running Infrared analyzer Another way to check for exhaust gases in the coolant What is the name of the test that uses colored liquid to find exhaust gases in the cooling system? Block check test A transmission heat exchanger has failed. Technician A says that if the engine is running, oil will flow from the transmission to the radiator. Technician B says that when the engine is turned off, coolant will flow into the transmission. Who is right? Both