Cooling System Questions TheoryUsing the information in i:\wellwood\mechanics\cooling.html, the internet and othersources to answer the following questions:

There are NO Partial Marks - when it says “describe” – DESCRIBE

1. One purpose of the cooling system is to maintain an optimum operating temperature. What are two reasons for this?

a.

b.

2. VIDEO QUESTION: Most air cooled engines use cooling fins, making the exposed surface

area as large as possible, which allows more heat energy to _______________ away, and be carried off in _______________ currents in the air.

3. VIDEO QUESTION: A common way to maintain adequate air flow over the engine is to use a fan with _______________ and _______________ to direct air over the cooling fins. This helps maintain a cooler engine temperature in low speed driving or while idling.

4. VIDEO QUESTION: Fans are usually driven by a _______________ attached to the crankshaft.

5. Give one example of an air cooled CAR from each of these manufacturers:a. Volkswagen –

b. Porsche –

c. Chevrolet –

d. Honda –

document.docx 1 of 8 G Wellwood 2018

First and Last Name

6. VIDEO QUESTION: A water pump forces coolant through passages called _______________ in the engine block. If collects heat, and becomes hot itself. Heated coolant then returns to the _______________ for cooling.

7. VIDEO QUESTION: As the engine warms up, the coolant trapped in the engine gets hotter and hotter. This starts to open the _________________, allowing hot coolant to flow to the radiator.

8. Identify the components in the diagram below:

9. A radiator is used to dissipate heat. Since black absorbs heat (ever worn black clothing in summer?), why do YOU think radiators traditionally been painted black?

10. VIDEO QUESTION: The radiator has two _______________ and a _______________

11. VIDEO QUESTION: A crossflow radiator fits more easily under a _______________ hood.

document.docx 2 of 8 G Wellwood 2018

12. VIDEO QUESTION: Heat is removed from the coolant by _______________ then by _______________ and _______________ at the surface of the fins.

13. DESCRIBE, using your own words, HOW a radiator cap works to MAINTAIN system pressure

14. VIDEO QUESTION: In a recovery system, hot coolant flows out into an _______________ container.

15. VIDEO QUESTION: What stops atmospheric pressure from collapsing the radiator hoses?

16. A water pump circulates engine coolant through what three components?a.

b.

17. How is the water pump commonly driven?

document.docx 3 of 8 G Wellwood 2018

18. Identify the components in the diagram shown here:

19. A core-plug is improperly referred to as a “frost plug”a. Why are they called “core plugs?”

b. Why are they called “frost plugs?”

document.docx 4 of 8 G Wellwood 2018

20. How do you remove a frost plug?

21. When installing frost plugs, what should you use to seal them?

22. What is one way of telling if your head gasket is blown and letting combustion gasses into the cooling system?

23. What are two ways to diagnose a leaking heater core?a.

b.

24. VIDEO QUESTION: DESCRIBE using your own words how a thermostat MAINTAINS engine temperature

25. Most thermostats today are designed to fail in the “open” position. Why do you think they are designed to fail OPEN?

26. There are six common causes of radiator hose failure are listed below. How would you identify each type of failure listed below (Google: "hose failure" site:gates.com )?

a. Leakage

b. Oil Damage

document.docx 5 of 8 G Wellwood 2018

c. Heat Damage27. VIDEO QUESTION: Why must flexible radiator hoses be used?

28. Some cooling fans run constantly. Some are designed to turn on only when needed. DESCRIBE using your own words HOW each of the following fans are ACTIVATED:

a. Fan Clutch type

b. Electric Cooling Fan

29. VIDEO QUESTION: Why are fan blades usually irregularly spaced?

30. Engine coolant contains Ethylene Glycol. Google a Material Safety Data Sheet (MSDS) and answer the following questions from the data on the sheet:

a. What safety equipment should be worn when handling antifreeze?

b. What should you do if you get antifreeze in your eyes?

c. What should you do if you accidently ingest antifreeze?

d. How much antifreeze will kill a 1Kg Rat? (it's in the MSDS)

document.docx 6 of 8 G Wellwood 2018

31. VIDEO QUESTION: An effective coolant must therefore contain good heat transfer properties, have a higher _______________ point and lower _______________ point than water, prevent _______________ and erosion, resist foaming, be compatible with cooling system _______________, be compatible with hard water, resist sedimentation, and be as _______________ stable as possible.

32. VIDEO QUESTION: Below 33% Glycol, the coolant will give inadequate _______________ protection

33. VIDEO QUESTION: Above 66% Glycol, the mixture has inadequate _______________ absorption.

34. VIDEO QUESTION: Coolant should be changed at recommended intervals because some of the additives will _______________ and deteriorate over time.

35. VIDEO QUESTION: Mixing different types of coolant is _______________ recommended.

36. Two tools are used in testing the cooling system. One is pictured to the right. What is it called, and how is it used?

37. The other tool used in testing the cooling system is pictured to the right. What is it called, and how is it used?

document.docx 7 of 8 G Wellwood 2018

38. DESCRIBE in your own words the ENTIRE step-by-step procedure for FLUSHING engine coolant.

document.docx 8 of 8 G Wellwood 2018