Roodeparkschool

Motors

Term 3:Date:_________________

Hand Tools (Uses and Safety)

1. Hammers:

Hammers have many uses, and when used correctly, is a valuable tool to have. Though anybody can pick up a hammer and strike something, using it incorrectly will most certainly cause damage for which you will be responsible, but can cause injuries just as easily. The quality of a mechanic can be measured by how he uses a hammer.

Ball-Peen Hammer

This is the hammer that a mechanic uses. They come in different weight/sizes. Both the ball and the peen can be used to strike with.

1. Always grip the end of the handle with a firm grip, but not white-knuckles!

2. Never grip the neck just below the hammer-head.

3. Never use one hammer to strike the head of another hammer.

4. Do not play with a hammer, or pretend to strike a person with a hammer.

Later on you will learn to use Copper- and Plastic-hammers

2. Screw Drivers:

Screwdrivers are meant to loosen or fasten screws according to the shape of the screw-head.

Make sure you know the different types, as using the incorrect type will cause damage to both the screwdriver and the screw head.

· Never use a screwdriver as a chisel with a hammer!

· When force needs to be applied, take care to not stab the screwdriver through your other hand.

Some of the most common screwdriver types:

3. Pliers:

Pliers have very specific uses in motor-repair. In a motor workshop they are mostly used for gripping hose-clamps, cutting wires and holding a workpiece. There are many different types of pliers depending on the job requirements.

3.1

3.2 Combination Pliers are one of the most common types as they usually have two different grip surfaces and cutting capability for multiple uses.

3.3 Side cutters are for more precision cutting of wires.

3.4 Water-pump pliers have jaws that can adjust in size.

3.5 A vice grip can also be adjusted for size, and the jaws can be locked once a firm grip has been established.

3.6 Longnose/Needlenose pliers are for gripping small items or when working in tight spaces.

3.7 Circlip pliers are for removing circlips. Their design does not usually allow them to be used for anything else.

Term 3:

Lesson 2:Date:_________________

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Hand Tools (Uses and Safety)

1. Spanners:

Spanners are the first tool in a mechanics toolbox. They are used for loosening and tightening bolts and nuts. Although there are several different types and styles, in the end they all do this one job.

1.1.1 Always use the correct size for the head of the bolt/nut.

1.1.2 There are never two sizes that will work on one bolt.

1.1.3 Make sure the spanner is seated properly over the head or the head will strip.

1.2

1.3 Open ended spanner.

1.4 Combination Spanner.

This spanner is an open end spanner on one side, and a ring-spanner on the other end. That is why it is called a combination spanner.

1.5 Combination swivel-ring spanner.

1.6 This is a shifting spanner. Although it has the advantage of adjusting according to the size of the bolt-head, they are difficult to adjust correctly and often wears down the bolt to a point where it is stripped and can no longer be removed. Avoid using the shifting spanner on a car at all costs.

1.7 Wrenches:

A wrench is another word for spanner, and is used in other countries like America.

Although in South Africa we like to talk about one particular wrench...

Pipe Wrench.

Mostly used by plumbers, there are a small amount of times when a mechanic needs to call on the services of this versatile tool. It can grip round surfaces as its design allows its grip to become tighter, the more force you apply to the handle. Please note that when used on a perfectly normal bolt-head, it will damage the head.

2 Tyre tread gauge:

A tyre tread gauge is used to measure the tread depth of a tyre. This indicates if the tyres are still usable or needs to be replaced. New tyres can have a tread depth of between 6mm to 12mm. In South Africa the lowest legal tread depth is 2mm. Anything below 2mm is measured as excessive wear, and means the tyres need to be replaced.

There are a couple of different types of gauges on the market:

· Place the flat end of the gauge on the surface of the tyre.

· Move the needle down into the grooves of the tyre pattern.

· Read the measurement on the dial

Term 3:

Lesson 3:Date:_________________

Identify Basic Serviceable Parts:

Exterior:

3.1 Wiper blades

Wiper blades wipe rain from the windshield to ensure a clear view for the driver.

The blade part is usually made from a soft rubber and silicon mixture. From wiping over the glass, the edges of the blade wear down due to friction, and then they do not wipe the windscreen clear effectively anymore. The sun also hardens the rubber over time causing them to crack, and the effectiveness is lost. They need to be checked at each service interval and replaced when needed.

You can usually determine what is wrong with the blade, according to one of the above symptoms. But since it can usually not be repaired, it is common practice to replace.

There are different ways to attach the blades to the wiper arms. Simple but effective hooks and clips will fasten them sufficiently. By simply looking at the clips, you will be able to determine how to unfasten or re-attach them.

In South Africa with our harsh sun and sometimes heavy rainfall, wiper blades last generally for one year.

2. Dipstick, Oil and Top up:

Oil is the BLOOD of an engine. It needs to be replaced with each service as oil starts to break down the minute it has to work in the engine. Great care needs to be taken to keep the oil level just right. Too much oil will result in oil seal failures, resulting in the loss of oil. Too little oil will not be able to lubricate the entire engine, and will result in engine failure.

2.1

2.1.1 Locate the dipstick in the engine bay.

2.1.2 Pull the dipstick out of the tube

2.1.3 Wipe clean.

2.1.4 Insert back into tube and leave 3 seconds.

2.1.5 Remove dipstick and hold horizontally, taking care not to drip oil on the engine or body panels.

2.1.6 Check the oil level.

Important:

Engine should be switched off, as an accurate reading cannot be taken while the engine is running!

Allow at least 30 seconds to 1 minute AFTER the engine has been shut off before checking oil level. The oil needs to settle in the sump after being pumped through the engine.

Brake fluid top-up:

Locate the brake fluid reservoir on top of the brake master cylinder. Usually the cap will have writing on it stating: Brake Fluid.

Make sure you have clean brake fluid of the correct rating (DOT4)

Check where the MIN and MAX lines on the reservoir are situated.

Top up the brake fluid as required until the level corresponds with the Max or Full line.

Important:

If the brake fluid level is between the MIN and MAX lines, the vehicle can still be used.

If the level is below the MIN line however, the problem should be fixed immediately without driving further.

Learner activity 1:

Draw an engine oil dipstick below inicating the oil level. State in your own words where the level is and if it is neccessary to add oil or top-up.

Motors

Term 3:

Lesson 4:Date:_________________

Plugs, Filters, Oil, and Fluids in Two and Four stroke Engines

4.1 Spark plugs:

Spark Plugs provide the electrical spark to ignite the air/fuel mixture in the combustion chamber. Generally there are one plug for each cylinder, although there is some specialised engines that make use of two plugs per cylinder. An engine will be designed to run off a specific type of spark plug, and can therefore not be interchangeable or used on different engines.

Factors that would influence the choice of spark plug could be:

4.1.1 Space available, operating heat(in combustion chamber),

4.1.2 Size of combustion chamber,

4.1.3 Compression levels,

4.1.4 Reliability and longevity/quality.

1.2 How to change:

Spark plugs are amongst the parts in the car that naturally wears down with daily use, and needs to be replaced during a service. Since the use of unleaded fuel, it has been noted that the plugs generally last longer than before. New technology like platinum tipped plugs also tend to last longer. It is now not so uncommon anymore for some spark plugs to last so long that some manufacturers suggest that the plugs only be changed every 90 000km’s! That is one replacement per every 4th to 5th service! Refer to the vehicle manual or workshop guide to determine which parts need to be replaced at the current mileage.

The spark plugs screw into the head, so the tips are exposed to the combustion chamber. Before undoing them, use compressed air to blow the area clean around them to prevent that dirt and debris from falling into the cylinder. Carefully unscrew them with a sparkplug socket. Take note of the wire you removed from the spark plug and return the right wire to the plug. If you swop them around, the timing will be wrong and the engine would probably not even start. Insert the new plugs and tighten them all the way down by hand. The box in which the spark plug came usually gives specifications to tightening levels, but usually is half a turn to ¾ turns further. Replace the wire.

1.3 Safety considerations:

Take care not to drop anything into the hole where the spark plug came out. If you do this, you will need to remove the whole head and use a new head gasket. At your own time and cost. Never overtighten a spark plug. If it breaks off, the amount of time and labour it would cost will also be for your own time and cost. Check the new spark plug gap before inserting. It happens sometime that they fell of the shelf at the parts store and closed.

2. Filters:

Filters generally need to be replaced at every service. No matter how technology improves to help the filters do a better job, once they are dirty, they cannot be cleaned and must be replaced.

2.1.1 Oil Filter

2.1.2 Air Filter

2.1.3 Fuel Filter

2.2 How to change:

Oil filters usually screw onto the engine block and looks like a can. Some manufacturers like to use a more permanent housing where you only replace the filter-type cartridge insert.

2.3 Air filters come in all shapes and sizes but are easy to spot and undo or replace.

2.4 Fuel filters needs to be traced on the fuel lines from the tank to the engine. Some are attached by hose clamps and some with plastic clips.

Safety considerations:

2.4.1 When undoing the oil filter, take care of the residual oil that will fall out. Clean oil spills on the floor as fast as possible as it is a liquid that is designed to be slippery.

2.4.2 When changing the air filter, take care not to drop any bolts/nuts or dirt into the opening, as this will be pulled into the combustion chamber immediately at start-up of the engine.

2.4.3 Residual fuel in the filter will also fall out when removing it. Remember that fuel burns rapidly and needs only a spark to ignite. Even a static electricity spark from your clothes will work.

3. Fluids:

There are some other fluids that a vehicle needs to operate.

3.1.1 Anti-freeze

3.1.2 Water

3.1.3 Brake fluid

3.1.4 Power steering oil

3.1.5 Gearbox oil

3.1.6 Differential oil

These do not have to be replaced at every service, but their levels need to be checked regularly. The manufacturer specifies at which service intervals they need to be drained and replaced.

Learner Activity:

1. List the tasks to perform on a minor service.

1.1 Replace _____________________

1.2 Replace _____________________filter.

1.3 Check _______________________

2. List the tasks to perform on a major service.

2.1 Replace ___________________

2.2 Replace ___________________filter.

2.3 Replace ___________________filter.

2.4 Replace ___________________filter.

2.5 Replace ___________________plugs.

2.6 Check _____________________

3. Items specified at scheduled services:

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