Which action should be performed to ensure lubrication system priming before startup?

Which action should be performed to ensure lubrication system priming before startup?

• A. Release the parking brakes
• B. Compression test
• C. Cylinder leakage test
• D. Prime the lubrication system

Answer: (D)

Priming the lubrication system ensures oil is in the pump and all passages so oil pressure builds quickly once the engine starts. This prep gets bearings, cams, and other moving parts immediately lubricated, preventing dry-start wear and potential damage during the first moments of operation. Without priming, the engine can spin without adequate lubrication, leading to accelerated wear or failure. The other actions don’t address lubrication readiness. Releasing parking brakes is a safety/vehicle control step, and compression or cylinder leakage tests assess sealing and compression, not whether the oil system is ready to supply lubrication.

Priming the lubrication system ensures oil is in the pump and all passages so oil pressure builds quickly once the engine starts. This prep gets bearings, cams, and other moving parts immediately lubricated, preventing dry-start wear and potential damage during the first moments of operation. Without priming, the engine can spin without adequate lubrication, leading to accelerated wear or failure.

The other actions don’t address lubrication readiness. Releasing parking brakes is a safety/vehicle control step, and compression or cylinder leakage tests assess sealing and compression, not whether the oil system is ready to supply lubrication.