Lubrication Systems & Maintenance Flashcards
7 cards from real CLS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Lubrication Systems & Maintenance flashcards as text
When inspecting a circulating oil lubrication system, a technician notices the oil level in the reservoir is dropping faster than expected. What is the MOST likely cause?
Answer: External leaks or excessive foaming causing overflow
Rapid reservoir level drops typically indicate external leaks at seals or fittings, or severe foaming causing oil to overflow from the reservoir breather.
What is the recommended approach when switching from a mineral-based lubricant to a synthetic in a circulating system?
Answer: Drain, flush the system, and refill with synthetic
A proper drain and flush removes residual mineral oil and incompatible additives before introducing synthetic lubricant to prevent contamination and additive interaction.
What is the purpose of a magnetic drain plug in a gearbox?
Answer: To capture ferrous wear particles and prevent recirculation
Magnetic drain plugs attract and hold ferrous metal wear particles, preventing them from recirculating through the gearbox and causing additional wear.
In a grease lubrication system using progressive divider valves, how is a blocked outlet typically detected?
Answer: A pressure indicator or cycle switch on the divider valve activates
A blocked outlet causes pressure to build in the progressive valve, triggering a built-in pressure indicator (pin indicator or cycle switch) that signals the fault.
Which parameter BEST indicates the remaining useful life of a circulating oil system lubricant?
Answer: Remaining base number (BN) or acid number (AN) trend
Tracking the base number (BN) depletion or acid number (AN) rise through oil analysis indicates how much additive reserve remains and predicts when the oil must be changed.
What is the main function of a vented (breather) cap on a lubricant reservoir?
Answer: To allow air exchange while filtering out contaminants
A breather cap allows air to flow in and out as the oil level changes while filtering particulate and moisture contamination from incoming air.
A grease-lubricated bearing shows signs of overheating. After verifying cooling is adequate, what lubrication-related cause should be investigated FIRST?
Answer: Bearing housing is over-packed with grease
Over-packing a bearing housing with grease creates excessive churning resistance, generating heat; this is one of the most common causes of grease-lubricated bearing overheating.