🔍 Key Concepts

• reciprocating air compressor components (crank, piston, valves, unloaders) • difference between mechanical looseness and pressure/load problems • why a symptom in one cylinder only is important

💭 Think About

• Which of these choices would most likely create a sharp, repeating mechanical noise in rhythm with piston movement? • If only one cylinder is noisy, which parts are unique to that cylinder, and which are common to the whole compressor? • Which options would mainly affect pressure or performance, rather than creating a distinct knocking sound?

✅ Before You Answer

• Identify which listed part, if loose or damaged, would actually move and strike against other parts as the piston runs. • Separate choices that mainly cause pressure or capacity problems from those that cause a distinct knock. • Ask yourself: would this fault reasonably occur in just one cylinder, matching the question wording?