Maintenance & Repair Procedures Flashcards

Why do most lock manufacturers advise against lubricating pin tumbler cylinders with heavy petroleum oil?

Answer: It attracts dust and grit that gum up the pin chambers

Sticky oils collect debris that binds pins, so dry graphite or PTFE-based lock lubricants are preferred.

A hydraulic door closer is leaking oil from its body. What is the standard corrective action?

Answer: Replace the closer

A leaking closer has failed seals and is generally not field-repairable, so it should be replaced.

Which door closer adjustment controls door speed during the last few inches before the door latches?

Answer: Latch speed valve

The latch valve controls the final closing segment so the door latches without slamming.

What is the purpose of the backcheck function on a door closer?

Answer: Cushion the door's opening swing before it reaches the stop

Backcheck provides hydraulic resistance near the end of the opening swing to protect the door, frame, and wall.

A latch bolt hits the bottom lip of the strike plate on a door that used to close correctly. What is the most likely cause and fix?

Answer: Door has sagged; tighten the top hinge with long screws into the jamb stud

A sagging door drops the latch below the strike opening, and long screws into the framing in the top hinge pull it back up.

A key has snapped off inside a cylinder with the plug in the locked position. What tool is normally used first?

Answer: Broken key extractor

A thin hooked broken key extractor slips along the key blade to pull the fragment out without damaging the cylinder.

A customer's lock works only intermittently with a heavily worn key. What is the best practice?

Answer: Cut a new key to the original code rather than copying the worn key

Cutting by code restores the correct factory depths, while copying a worn key keeps the wear in the new key.