Which items are checked for leaks during the vacuum test?

• A. Hard suction hose
• B. Pump
• C. Priming device
• D. All of the above

Answer: (D)

The vacuum test is about confirming that the entire suction-priming path can hold a vacuum without letting air in. Any leak along that path will ruin the prime, so you inspect every part that could admit air. The hard suction hose must be airtight along its length and at its fittings, the pump itself must not have internal leaks that allow air to bypass the priming path, and the priming device or chamber must seal properly and be able to develop and sustain the vacuum. Since leaks can occur in any of these components, the test checks them all, making “All of the above” the best answer.