Photo AI
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, follow these steps:
- Install the cap onto the cooling system pressure tester.
- Pump up the tester to the rated pressure as indicated on the cap. Observe the pressure gauge closely during this process.
- The pressure cap should release air at the rated pressure stamped on it. Ensure to monitor whether it maintains the applied pressure.
- Finally, hold the pressure on the tester for at least one minute. If the cap does not maintain pressure, it must be replaced.
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 for a pressure drop may include:
- Leaks between components of the cooling system, such as hoses or gaskets.
- Blown cylinder head gasket.
Corrective measures include:
- Renew faulty hoses and secure clamps to prevent leaks.
- Replace the blown cylinder head gasket.
Step 3
State TWO manufacturers' specifications that could be used to conduct a cooling system pressure test.
Answer
To conduct a cooling system pressure test, check for the following specifications:
- The water and anti-freeze ratio in the cooling system should meet manufacturer recommendations.
- The pressure allowed in the radiator should match specifications provided by the vehicle manufacturer.
Step 4
State FOUR safety measures while setting up a compression tester on an internal combustion engine.
Answer
When setting up a compression tester, ensure to:
- Use a tester that can handle the pressure you intend to measure.
- Clean the spark plug area to prevent dirt from entering when removed.
- Ensure all rubber hoses and components on the tester are in good condition.
- Disconnect fuel feed lines to prevent any fuel spillage during testing.
Step 5
Complete TABLE 8.5 by giving ONE cause and ONE appropriate corrective measure for EACH fault.
Answer
For the gas analysis results:
- High carbon monoxide (CO) reading:
- Cause: Too rich fuel mixture.
- Corrective Measure: Reset fuel mixture.
- Low carbon dioxide (CO2) reading:
- Cause: Exhaust system leaks.
- Corrective Measure: Repair exhaust system.
- High hydrocarbon (HC) reading:
- Cause: Excessive unburned fuel due to improper timing.
- 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
To conduct a fuel pressure test, verify the following specifications:
- Fuel pressure must meet manufacturer specifications when the engine is off.
- Ensure proper fuel pressure when the engine is idling and also at high revolutions to ensure fuel delivery is adequate.