Lesson Note on Air Cleaner, Functions of Air Cleaner, Servicing of Air Cleaner for SS2

Class: Senior Secondary School 2 (SS2 / SSS 2)
Term: 2nd Term
Week: 9
Age: 16 years
Duration: 45 minutes
Subject: Auto Mechanic Work
Curriculum Theme: Vehicle Maintenance
Previous Lesson: Caburettors—Remove and Replace Caburattors: Diagnosis and Maintenance.
Topic: AIR CLEANER, FUNCTIONS OF AIR CLEANER, SERVICING OF AIR CLEANER.
Subject Matter: Meaning of AIR CLEANER, functions of air cleaner, servicing of air cleaner, remove and replace air cleaner.

Specific Objectives

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

Cognitive Domain:

Instructional Materials

The teacher will teach this lesson with the aid of:

• A live vehicle with an accessible air cleaner
• Spanner set
• Hammer (if needed for stubborn parts)
• Charts illustrating different types of air cleaners
• New and old air cleaner filters
• Cleaning cloth and compressed air source (if available)

Rationale for the Lesson

This lesson helps pupils understand the crucial role of the air cleaner in engine performance and longevity. It also equips them with the practical skills needed to properly maintain and replace this important engine component, which is vital for vehicle care.

Prerequisite/Previous Knowledge

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

Lesson Content/Board Summary

AIR CLEANER AND ITS MAINTENANCE

Meaning of Air Cleaner

An air cleaner, also known as an air filter, is a device consisting of fibrous material which removes solid particulates such as dust, pollen, and dirt from the air supplied to an engine. It is usually located at the air intake system of the engine.

Functions of Air Cleaner

The main functions of an air cleaner in an engine are:

• Filtering Dust and Debris: It prevents harmful dust, dirt, and other airborne particles from entering the engine’s combustion chambers.
• Protecting Engine Components: By filtering the air, it protects sensitive engine parts like cylinders, pistons, and valves from abrasion and wear caused by foreign particles.
• Ensuring Optimal Combustion: A clean air supply ensures proper air-fuel mixture, leading to efficient combustion and better engine performance.
• Reducing Emissions: A well-maintained air cleaner contributes to cleaner exhaust emissions by supporting efficient fuel burning.

Importance of Servicing Air Cleaner

Regular servicing of the air cleaner is important because:

• A dirty or clogged air cleaner restricts airflow to the engine, causing reduced engine power.
• It can lead to increased fuel consumption as the engine struggles to draw in enough air.
• It can cause the engine to run rich, leading to carbon build-up and increased emissions.
• It can allow unfiltered air to enter the engine, causing premature wear and damage to internal components.

Steps for Servicing an Air Cleaner (Cleaning or Replacement)

Servicing an air cleaner involves either cleaning it or replacing it, depending on its type and condition:

• Inspection: Visually inspect the filter element for dirt, damage, or clogging.
• Cleaning (for reusable filters): Use compressed air to blow out dirt from the inside out, or wash with appropriate cleaning solution if specified by the manufacturer.
• Replacement (for disposable filters): If the filter is disposable or too dirty/damaged to clean effectively, replace it with a new, correct-fitting filter.
• Housing Cleaning: Clean the air cleaner housing and ensure no debris remains before installing the filter.
• Proper Sealing: Ensure the filter is correctly seated and the housing is properly sealed to prevent air leaks.

Procedure to Remove and Replace an Air Cleaner

The general steps for removing and replacing an air cleaner are:

• Locate the Air Cleaner Assembly: Identify the air cleaner housing, usually a large plastic or metal box connected to the engine’s air intake.
• Open the Housing: Release the clips, screws, or clamps holding the air cleaner housing cover in place.
• Remove the Old Filter: Carefully lift out the old air filter element from the housing. Note its orientation.
• Clean the Housing: Wipe the inside of the air cleaner housing to remove any accumulated dirt or debris.
• Insert the New Filter: Place the new air filter element into the housing, ensuring it is seated correctly and in the proper orientation.
• Close the Housing: Replace the cover and secure all clips, screws, or clamps firmly.
• Check Connections: Ensure all hoses or ducts connected to the air cleaner assembly are reconnected securely.

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 what they think protects an engine from dirt and dust.
Pupils’ Activity: Pupils respond, mentioning various components, and the teacher guides them towards the air cleaner.
Learning Point: Pupils are introduced to the concept of engine protection from airborne particles.

Step 2: Meaning of Air Cleaner

Time: 7 minutes
Teaching Skill: Explanation/Definition
Teacher’s Activity: The teacher defines what an air cleaner is, pointing to a diagram or the actual component on the vehicle.
Pupils’ Activity: Pupils listen attentively and copy the definition into their notes.
Learning Point: Pupils understand the basic definition of an air cleaner.

Step 3: Functions of Air Cleaner

Time: 7 minutes
Teaching Skill: Elaboration/Listing
Teacher’s Activity: The teacher explains the various functions of the air cleaner, such as filtering dust, protecting the engine, and ensuring proper combustion.
Pupils’ Activity: Pupils state the functions of the air cleaner and ask questions for clarification.
Learning Point: Pupils learn the importance and roles of the air cleaner in engine operation.

Step 4: Servicing of Air Cleaner

Time: 8 minutes
Teaching Skill: Explanation/Instruction
Teacher’s Activity: The teacher explains the importance of regular air cleaner servicing and outlines the steps involved in cleaning or replacing it.
Pupils’ Activity: Pupils listen and take notes on the servicing procedures.
Learning Point: Pupils understand why and how an air cleaner should be serviced.

Step 5: Demonstration of Removal and Replacement

Time: 8 minutes
Teaching Skill: Demonstration
Teacher’s Activity: The teacher demonstrates the step-by-step procedure for removing and replacing an air cleaner using a live vehicle.
Pupils’ Activity: Pupils observe the demonstration carefully, noting the tools used and the sequence of actions.
Learning Point: Pupils visually learn the practical steps for handling an air cleaner.

Step 6: Practical Session

Time: 5 minutes
Teaching Skill: Practical Application
Teacher’s Activity: The teacher guides a few pupils to practice removing and replacing the air cleaner under supervision.
Pupils’ Activity: Pupils actively participate in the practical exercise, practicing the removal and replacement of the air cleaner.
Learning Point: Pupils gain hands-on experience in air cleaner maintenance.

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 an air cleaner?
2. State three functions of an air cleaner.
3. Mention two reasons why servicing an air cleaner is important.
4. List three steps involved in removing and replacing an air cleaner.

Pupils’ Activity: Pupils answer orally and in writing.
Learning Point: Pupils demonstrate understanding of the lesson.

Step 8: Conclusion

Time: 5 minutes
Teaching Skill: Summarization
Teacher’s Activity: The teacher summarizes the key points of the lesson, emphasizing the importance of proper air cleaner maintenance for engine health. The teacher then assigns homework, asking pupils to draw and label an air cleaner assembly.
Pupils’ Activity: Pupils listen to the summary, ask final questions, and note down the homework.
Learning Point: Pupils consolidate their understanding of the lesson.

Lesson Keywords

• Air Cleaner – A device that removes solid particulates from the air supplied to an engine.
• Filter – A porous material used to remove impurities from a fluid or gas.
• Engine Protection – The act of safeguarding engine components from damage.
• Servicing – The act of maintaining or repairing a machine or system.
• Replacement – The act of putting something new in place of something old or broken.
• Dust – Fine dry powder consisting of tiny particles of earth or other matter.

Differentiation

For pupils who grasp concepts quickly, the teacher can challenge them to identify different types of air cleaners and their specific applications. For pupils needing more support, the teacher will provide additional one-on-one guidance during the practical session and simplify explanations with more visual aids.

Note for teachers using this lesson plan

Ensure all safety precautions are followed during the practical demonstration and pupil activities, especially when working with a live vehicle. Emphasize the correct use of tools and the importance of cleanliness. Encourage pupils to ask questions and share their observations.