USPS Maintenance & Mechanics 3

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?

Accepted Answer

System was over-pressurized beyond the rated maximum

Answer

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?

Accepted Answer

1/4 inch deflection is too tight and should have been corrected

Answer

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?

Accepted Answer

Total cost should be $27.00 — no error

Answer

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?

Accepted Answer

PM is overdue — 310 hours exceeds the 250-hour interval

Answer

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?

Accepted Answer

The machine was re-energized at the same time work was completed, with no clearance step

Answer

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.

USPS Error Detection Test Practice Test

USPS Error Detection Test Practice Test

USPS Maintenance & Mechanics 3