Lesson Note on Cooling System—Air Cooling, Water and Air Cooling System: Identify Parts and Removal for SS2

Class: Senior Secondary School 2 (SS2 / SSS2)
Term: Second Term
Week: 5
Age: 16 years
Duration: 45 minutes
Subject: Auto Mechanic Work
Curriculum Theme: Vehicle Systems
Previous Lesson: Engine Lubrication—Oil Filters and Qualities of Lubricants: Viscosity Feel Test.
Topic: COOLING SYSTEM—AIR COOLING, WATER AND AIR COOLING SYSTEM.
Subject Matter: Meaning of COOLING SYSTEM—AIR COOLING, WATER AND AIR COOLING SYSTEM (definition of engine cooling), parts of cooling system (radiator, fan blade, fan belt, rubber hoses), removal of cooling system parts (demonstration).

Specific Objectives

By the end of the lesson, pupils should be able to:

Cognitive Domain:

• Define an engine cooling system.
• State the types of cooling systems.
• List at least five parts of a water cooling system.

Affective Domain:

• Appreciate the importance of a properly functioning cooling system.
• Observe safety precautions during the removal of cooling system parts.

Psychomotor Domain:

• Identify various parts of the cooling system from real models or charts.
• Demonstrate the safe removal of specific cooling system components like the fan belt and rubber hoses.

Social Domain:

• Collaborate with peers in identifying and discussing cooling system components.

Reference Materials

The following resources were used in planning this lesson:

• Senior Secondary Schools Education Curriculum
• State Unified Scheme of Work
• Auto Mechanic Work for Senior Secondary Schools Textbook
• https://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0900c1528006e87a
• https://www.youtube.com/watch?v=F0z-uLg2M0o

Instructional Materials

The teacher will teach this lesson with the aid of:

• A complete radiator
• Fan blade
• Fan belt
• Various rubber hoses
• Charts illustrating the cooling system
• Wrenches and screwdrivers for demonstration

Rationale for the Lesson

This lesson helps pupils understand how an engine prevents overheating, which is important for vehicle maintenance. Learning about the cooling system and its parts enables pupils to identify issues and perform basic repairs, ensuring vehicle longevity and safety.

Prerequisite/Previous Knowledge

Pupils have basic knowledge of internal combustion engines and their main components.

Lesson Content/Board Summary

COOLING SYSTEM

Definition of Engine Cooling System

The engine cooling system is a vital part of an internal combustion engine that removes excess heat generated during combustion. This prevents the engine from overheating and ensures it operates at its optimal temperature for efficiency and longevity.

Types of Cooling Systems

• Air Cooling System: This system uses air to cool the engine. It typically involves fins on the engine block that increase the surface area for heat dissipation, and a fan to force air over these fins. Common in motorcycles and some older vehicles.
• Water (Liquid) Cooling System: This system uses a liquid coolant (mixture of water and antifreeze) circulated through passages in the engine block and cylinder head. The hot coolant then flows to the radiator, where heat is transferred to the air, and the cooled liquid returns to the engine. This is the most common type in modern cars.

Parts of the Water Cooling System

The following are key components of a typical water cooling system:

• Radiator: A heat exchanger that transfers heat from the coolant to the ambient air.
• Fan Blade: Draws air through the radiator to enhance cooling, especially at low speeds or when stationary.
• Fan Belt: Drives the cooling fan and often the water pump, connecting them to the engine’s crankshaft.
• Rubber Hoses: Flexible pipes (upper and lower radiator hoses) that carry coolant between the engine, radiator, and other components.
• Water Pump: Circulates the coolant throughout the engine and cooling system.
• Thermostat: A temperature-sensitive valve that regulates the flow of coolant to the radiator, helping the engine reach and maintain its optimal operating temperature.
• Heater Core: A small radiator-like component that uses engine heat to warm the vehicle’s cabin.
• Coolant Reservoir/Expansion Tank: Holds excess coolant and allows for expansion and contraction of the coolant as it heats and cools.

Procedure for Removing Cooling System Parts (Demonstration Steps)

Proper safety and care must be taken when removing cooling system components.

General steps include:

• Step 1: Safety First – Ensure the engine is cool and disconnect the battery to prevent accidental starts.
• Step 2: Drain Coolant – Place a drain pan under the radiator and open the drain cock to empty the coolant.
• Step 3: Detach Hoses – Loosen hose clamps with a screwdriver or pliers and carefully pull off the rubber hoses (upper and lower radiator hoses).
• Step 4: Remove Fan Belt – Loosen the tensioner pulley and slide the fan belt off the pulleys (e.g., crankshaft, water pump, alternator).
• Step 5: Handle Radiator – If removing the radiator, disconnect any remaining mounts or electrical connections, then carefully lift it out.

Teaching Methods/Instructional Techniques

Discussion, Lecture, Demonstration, Question and Answer, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes
Teaching Skill: Set Induction
Teacher’s Activity: The teacher greets the pupils and asks them to recall the importance of an engine in a vehicle. The teacher then asks what happens if an engine gets too hot.
Pupils’ Activity: Pupils respond by stating that an engine powers the vehicle and if it gets too hot, it can get damaged.
Learning Point: Pupils are reminded of engine function and the problem of overheating.

Step 2: Definition of Cooling System

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines what an engine cooling system is and explains its primary purpose.
Pupils’ Activity: Pupils listen attentively and write down the definition in their notes.
Learning Point: Pupils understand the meaning and purpose of the cooling system.

Step 3: Types of Cooling Systems

Time: 7 minutes
Teaching Skill: Explanation/Classification
Teacher’s Activity: The teacher explains the two main types of cooling systems: air cooling and water (liquid) cooling systems, highlighting their basic principles.
Pupils’ Activity: Pupils listen, ask questions for clarity, and identify the different types.
Learning Point: Pupils learn about air and liquid cooling systems.

Step 4: Identification of Cooling System Parts

Time: 8 minutes
Teaching Skill: Demonstration/Identification
Teacher’s Activity: Using actual components (radiator, fan blade, fan belt, rubber hoses) and charts, the teacher guides pupils in identifying and naming the parts of a water cooling system.
Pupils’ Activity: Pupils observe the components, identify them, and mention other parts they know.
Learning Point: Pupils can identify key components of the cooling system.

Step 5: Demonstration of Parts Removal

Time: 8 minutes
Teaching Skill: Demonstration/Practical Skill
Teacher’s Activity: The teacher safely demonstrates the removal of some cooling system parts, such as detaching rubber hoses and removing the fan belt, emphasizing proper tools and techniques.
Pupils’ Activity: Pupils observe the demonstration carefully, noting the steps and tools used, and naming the parts being removed.
Learning Point: Pupils understand the practical steps involved in removing cooling system components.

Step 6: Safety Precautions

Time: 5 minutes
Teaching Skill: Explanation/Safety
Teacher’s Activity: The teacher discusses important safety precautions to take when working on a cooling system, such as ensuring the engine is cool and handling coolant properly.
Pupils’ Activity: Pupils listen and list the safety measures discussed.
Learning Point: Pupils learn about safety procedures for working with cooling systems.

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is the primary function of an engine cooling system?
2. Mention two types of engine cooling systems.
3. List three important parts of a water cooling system.
4. State one safety precaution to observe when working on a cooling system.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 2 minutes
Teacher’s Activity: The teacher summarizes the main points of the lesson and assigns homework: “Draw and label a simple diagram of a water cooling system.”
Pupils’ Activity: Pupils listen to the summary and copy down the homework.
Learning Point: Pupils review the lesson content and receive reinforcement activities.

Lesson Keywords

• Cooling System – A system designed to remove excess heat from an engine.
• Radiator – A device that transfers heat from the coolant to the air.
• Fan Blade – A component that pulls air through the radiator for cooling.
• Fan Belt – A belt that drives the fan and other engine accessories.
• Rubber Hoses – Flexible tubes that transport coolant.
• Air Cooling – A method of cooling an engine using air directly.
• Water Cooling – A method of cooling an engine using a liquid coolant.
• Thermostat – A valve that regulates coolant flow based on temperature.
• Water Pump – A component that circulates coolant through the engine.

Differentiation

The teacher will provide additional visual aids and simplified explanations for pupils who may struggle with understanding the mechanical concepts. More advanced pupils will be encouraged to research and present on the function of specific cooling system sensors or controls.

Note for teachers using this lesson plan

Ensure all demonstration materials are clean, safe, and easily visible to all pupils. Emphasize safety precautions thoroughly, especially when discussing handling used components or fluids. Encourage active participation and questions from pupils to gauge their understanding of the practical aspects.