MTC Preventive Maintenance Procedures 3

Question 1

When performing PM on a marine battery bank, what voltage reading on a fully charged 12V flooded lead-acid battery indicates acceptable state of charge?

Accepted Answer

12.6–12.8 V

Answer

A fully charged 12V flooded lead-acid battery at rest should read approximately 12.6–12.8 V; lower readings suggest partial or full discharge.

Question 2

A PM checklist calls for inspecting the marine AC generator's drive belt. Which finding requires immediate replacement?

Accepted Answer

Belt shows surface glazing, cracking, or fraying

Answer

Glazing, cracking, or fraying indicates belt degradation that can lead to slippage or sudden failure, interrupting battery charging and cooling.

Question 3

During a PM inspection of a marine vessel's through-hull fittings, what condition should prompt immediate haul-out and repair?

Accepted Answer

Dezincification (pinkish, porous appearance) or visible cracking of the fitting

Answer

Dezincification weakens brass/bronze fittings significantly, and a failed through-hull below the waterline can sink the vessel rapidly.

Question 4

What is the correct method to test a marine bilge pump's automatic float switch during PM?

Accepted Answer

Manually lift the float switch while observing pump activation

Answer

Manually lifting the float switch simulates rising water and confirms the pump activates without having to flood the bilge.

Question 5

When topping off a marine diesel day tank as part of a PM procedure, what is the correct reason to leave an air gap at the top of the tank?

Accepted Answer

To allow fuel to expand with temperature changes and prevent overflow

Answer

Diesel fuel expands as temperature rises, and leaving a small air gap prevents overflow through the vent or filler cap.

(MTC) Marine Technician Certification Practice Test

(MTC) Marine Technician Certification Practice Test

MTC Preventive Maintenance Procedures 3