USPS Maintenance & Mechanics 3 — Questions and Answers
Question 1: A maintenance technician's report reads: 'Replaced hydraulic cylinder seals on dock leveler #2. Fluid type used: AW-46 hydraulic oil. System re-pressurized to 3,200 PSI. Leak test: PASS.' The equipment spec card lists maximum system pressure as 2,500 PSI. What is the error?
- Wrong hydraulic fluid type was used
- System was over-pressurized beyond the rated maximum (Correct answer)
- The leak test should have been performed before re-pressurizing
- The cylinder seal type is unspecified
Correct answer: System was over-pressurized beyond the rated maximum
Re-pressurizing to 3,200 PSI exceeds the 2,500 PSI maximum rated pressure, risking equipment damage or injury.
Question 2: A PM (preventive maintenance) checklist shows: 'Check V-belt tension on mail sorting machine. Deflection should be 3/8 inch per 12 inches of span. Measured deflection: 1/4 inch. Action taken: None required.' What error did the technician make?
- The deflection measurement method is incorrect
- 1/4 inch deflection is too tight and should have been corrected (Correct answer)
- No error — 1/4 inch is within the acceptable range
- The span measurement should be in centimeters
Correct answer: 1/4 inch deflection is too tight and should have been corrected
A deflection of 1/4 inch is less than the required 3/8 inch, indicating the belt is over-tightened, which increases bearing wear.
Question 3: A work order completion record shows: 'Task: Replace air compressor filter. Filter P/N: AF-1142. Date: 04/10/2026. Labor hours: 0.5. Parts cost: $18.00. Total cost: $27.00.' If the labor rate is $18.00/hour, what is the error?
- The part number is missing a letter
- Total cost should be $27.00 — no error (Correct answer)
- Total cost should be $36.00, not $27.00
- The labor hours are unreasonably low
Correct answer: Total cost should be $27.00 — no error
0.5 hours × $18/hr = $9.00 labor + $18.00 parts = $27.00 total, which matches — there is no arithmetic error.
Question 4: An equipment tag reads: 'Forklift #7 — Last PM: 01/15/2026. Next PM due: 250 hours or 04/15/2026, whichever comes first.' The current date is 04/10/2026 and the hour meter reads 310 hours since last PM. What is the correct status?
- PM is not yet due — the date hasn't arrived
- PM is overdue — 310 hours exceeds the 250-hour interval (Correct answer)
- PM is due exactly today
- Both the date and hours must be exceeded before PM is required
Correct answer: PM is overdue — 310 hours exceeds the 250-hour interval
The 'whichever comes first' condition means the 250-hour threshold triggered the PM requirement before the April date arrived.
Question 5: A lockout/tagout (LOTO) log entry states: 'Machine de-energized: 10:15 AM. Energy source: 480V electrical only. Lock applied by: R. Thomas. Work completed: 11:45 AM. Machine re-energized: 11:45 AM.' What error is recorded in this log?
- The voltage listed is too high for postal equipment
- The machine was re-energized at the same time work was completed, with no clearance step (Correct answer)
- The lock should have been applied by a supervisor
- The LOTO duration of 1.5 hours is excessive
Correct answer: The machine was re-energized at the same time work was completed, with no clearance step
LOTO procedures require a formal clearance and verification step before re-energization, which is absent here since re-energization and work completion share the same timestamp.
Question 6: A requisition form lists: 'Qty: 6 | Item: Fluorescent lamp T8 48" 32W | Unit price: $3.50 | Extended: $24.00.' What is the error on this form?
- The wattage of the lamp is incorrect for postal use
- The extended price should be $21.00, not $24.00 (Correct answer)
- The lamp length is not appropriate for postal facilities
- There is no error on the form
Correct answer: The extended price should be $21.00, not $24.00
6 × $3.50 = $21.00, not $24.00, so the extended price contains an arithmetic error.
Question 7: A maintenance log notes: 'Adjusted dock door seal on Bay 12. Seal gap before: 1.5 inches. Seal gap after: 0.25 inches. Specification: gap must not exceed 0.5 inches. Result: PASS.' Is the technician's PASS determination correct?
- No — 0.25 inches exceeds the 0.5-inch limit
- Yes — 0.25 inches is within the 0.5-inch maximum limit (Correct answer)
- No — any gap at all constitutes a failure
- Yes — the gap improved, so the result is always PASS
Correct answer: Yes — 0.25 inches is within the 0.5-inch maximum limit
A 0.25-inch gap is less than the 0.5-inch maximum allowed, so the PASS determination is correct.
USPS Maintenance & Mechanics 3
A maintenance technician's report reads: 'Replaced hydraulic cylinder seals on dock leveler #2.
Fluid type used: AW-46 hydraulic oil.
System re-pressurized to 3,200 PSI.
Leak test: PASS.' The equipment spec card lists maximum system pressure as 2,500 PSI.
What is the error?