For drift test extension cylinders, what is the required setup before verification?

• A. Immediately test the extension while hot
• B. Wait 4 hours after setting temperature
• C. With hydraulic fluid at ambient temperature place device at full elevation and 10 ft of extension, then let it sit for 1 hour with the engine off
• D. Place device at full extension with no elevation

Answer: (C)

Drift testing extension cylinders is about checking for internal leakage when the cylinder is fully extended and bearing the weight of the system under static conditions. The proper setup uses hydraulic fluid at ambient temperature, places the device at full elevation with 10 ft of extension, and then lets it sit for about an hour with the engine off. This combination ensures the test measures true leakage without interference from pump pressure or temperature changes. If the fluid is tested when hot, viscosity shifts can mask or exaggerate leaks; if you test with the engine running, the pump could push fluid and hide drift; and without full elevation and extension, you’re not stressing the seals and leaks the way the system would operate in real use. Allowing an hour for the system to sit lets any small amount of drift become noticeable, giving a clear indication of cylinder integrity under the most demanding static condition.