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8.1 Explain the procedure used to test the radiator cap by using the cooling system pressure tester - NSC Mechanical Technology Automotive - Question 8 - 2019 - Paper 1
Question 8
8.1 Explain the procedure used to test the radiator cap by using the cooling system pressure tester. 8.2 State TWO possible causes and TWO corrective measures for p... show full transcript
Worked Solution & Example Answer:8.1 Explain the procedure used to test the radiator cap by using the cooling system pressure tester - NSC Mechanical Technology Automotive - Question 8 - 2019 - Paper 1
Step 1
Explain the procedure used to test the radiator cap by using the cooling system pressure tester.
Answer
To test the radiator cap using the cooling system pressure tester, follow these steps:
- Install the radiator cap onto the cooling system pressure tester.
- Pump the tester while monitoring the pressure gauge.
- Ensure the cap releases air at the rated pressure stamped on the cap.
- Hold the pressure for at least one minute to check for drops. If not installed, a new cap should be used.
Step 2
State TWO possible causes and TWO corrective measures for pressure drop on the tester used on a radiator or expansion tank of the cooling system on an internal combustion engine.
Answer
Possible Causes:
- Leaks between components of the cooling system, such as hoses or the radiator itself.
- Blown cylinder head gasket causing pressure loss.
Corrective Measures:
- Renew gaskets and seals to eliminate leaks.
- Replace the radiator or any faulty hoses.
Step 3
Step 4
State FOUR safety measures while setting up a compression tester on an internal combustion engine.
Answer
- Ensure the tester can handle the required pressure.
- Clean the spark plug area to prevent debris from entering.
- Ensure all rubber hoses on the tester are in good condition.
- Disconnecting the fuel leads before setup to prevent fuel spillage.
Step 5
Complete TABLE 8.5 by giving ONE cause and one appropriate corrective measure for EACH fault.
Answer
For High Carbon Monoxide (CO) reading:
- Cause: Too rich a fuel mixture.
- Corrective Measure: Reset fuel mixture settings.
For Low Carbon Dioxide (CO2) reading:
- Cause: Fuel mixture too rich or lean.
- Corrective Measure: Replace or repair air filter.
For High Hydrocarbon (HC) reading:
- Cause: Excessive unburned fuel due to incomplete combustion.
- Corrective Measure: Check and reset ignition system.
Step 6
State TWO manufacturers' specifications that could be used to conduct a fuel pressure test on a motor vehicle's fuel.
Answer
- The fuel pressure specifications should meet the manufacturer's stated pressure requirements.
- The fuel pump pressure should be checked when the engine is idling and at high revolutions.