• 50 questions

NOCTI Heavy Equipment Maintenance and Repair Practice Test

Unofficial practice for NOCTI Heavy Equipment Maintenance and Repair: engines, power trains, electrical, brakes, hydraulics, welding and undercarriage.

Which part regulates engine temperature by controlling how much coolant flows from the block to the radiator?

Pick an answer, then press Check answer. Then you see Correct or Not quite, with the reason. Keys: A to D pick, Enter checks.

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Exam mode: 50 questions, 52 minutes.

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Unofficial practice questions, not affiliated with NOCTI. Bank checked October 16, 2026.

Next step More engine questions: ASE T2Another NOCTI test: Diesel Technology

All 50 questions

Maintain and Repair Engine 8

  • A full-flow oil filter has a bypass valve built in. What is that valve for? US Army TM 9-8000, Principles of Automotive Vehicles (1985), chapter 8. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
  • A machine with selective catalytic reduction (SCR) burns through diesel exhaust fluid. What does the SCR system lower in the exhaust? Wikipedia, Diesel exhaust fluid. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
  • In a four-stroke engine, on which stroke does the piston rise from bottom dead center with both valves closed? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 2-6. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
  • Most diesel fuel systems carry two filters. Where does the primary filter usually sit? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 5-35. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
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Maintain and Repair Engine, continued

  • Near top dead center the intake valve starts to open before the exhaust valve has closed. What is this period called? US Army TM 9-8000, Principles of Automotive Vehicles (1985), chapter 2. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
  • On a turbocharged diesel, what does the intercooler do? Wikipedia, Intercooler. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
  • Which part regulates engine temperature by controlling how much coolant flows from the block to the radiator? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 9-9. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine
  • Which piston ring keeps the engine's lubricating oil from getting into the combustion chamber? US Army TM 9-8000, Principles of Automotive Vehicles (1985), chapter 3. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Engine

Maintain and Repair Power Train 5

  • A drive line runs to an axle at an angle that keeps changing. Which coupling lets one shaft drive another at an angle? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 28-3. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Power Train
  • In a hydrostatic drive, where does the engine-driven pump send oil under pressure? Wikipedia, Continuously variable transmission, Hydrostatic/hydraulic. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Power Train
  • In a mechanical transmission a 12-tooth gear drives a 36-tooth gear. Ignoring friction, what happens at the larger gear? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 19-3. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Power Train; the arithmetic was worked twice
  • Many power shift transmissions change ratio under load through planetary gearsets. In an automatic transmission, what locks the elements of those gearsets? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 23-3. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Power Train
  • What does a final drive do to the speed that comes down the propeller shaft? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 29-8. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Power Train

Maintain and Repair Electrical System 6

  • A battery carries a rating in cold cranking amperes (CCA). At what temperature is that rating measured? Wikipedia, Automotive battery, Cranking amperages. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Electrical System
  • A lighting circuit keeps blowing its fuse. What is the fuse doing each time it blows? Wikipedia, Fuse (electrical). Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Electrical System
  • Besides connecting the battery to the starter motor, what does the starter solenoid do? Wikipedia, Starter solenoid. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Electrical System
  • The electronic control units of a modern machine are linked by a CAN bus. What is a CAN bus designed to do? Wikipedia, CAN bus. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Electrical System
  • How does the voltage regulator of an alternator hold a constant voltage at the battery terminals? Wikipedia, Alternator (automotive), Field regulation. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Electrical System
  • Two 60-watt work lamps are wired to a 12-volt lighting circuit. How much current do they draw together? Wikipedia, Electric power, Resistive circuits. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Electrical System; the arithmetic was worked twice

Maintain and Repair Brake System 5

  • A master cylinder piston of 1 square inch is pushed with a force of 150 pounds. How much force does a wheel piston of 3 square inches deliver? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 20-2. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Brake System; the arithmetic was worked twice
  • During an air brake inspection the air dryer is checked. What does the air dryer take out of the compressed air? Wikipedia, Air brake (road vehicle), Supply system. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Brake System
  • In an S-cam air brake, what happens when the camshaft turns? Wikipedia, S-cam. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Brake System
  • On a disc brake, which stationary component holds the pads and the hydraulic pistons that press them on the rotor? US Army TM 9-8000, Principles of Automotive Vehicles (1985), chapter 34. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Brake System
  • Which unit of a hydraulic brake system turns the force of the operator's foot into fluid pressure? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 34-25. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Brake System

Welding 3

  • A bucket is welded in a shop bay where combustible material cannot be moved away, so a fire watch is posted. How long must the watch go on after the welding stops? OSHA, 29 CFR 1910.252, paragraph (a)(2)(iii)(B). Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Welding
  • In shielded metal arc (stick) welding, what does the flux covering of the electrode do as it burns away? Wikipedia, Shielded metal arc welding. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Welding
  • Which metal is an alloy of iron and carbon with a carbon content of more than 2%? Wikipedia, Cast iron. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Welding

Preventive Maintenance 6

  • A hydraulic system inspection includes the filters. What do hydraulic filters take out of the fluid? Wikipedia, Hydraulic machinery, Filters. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Preventive Maintenance
  • A lubrication chart calls for a grease gun at each pin and bushing. What is the small metal fitting the gun snaps onto? Wikipedia, Grease fitting. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Preventive Maintenance
  • A tire's recommended inflation figure is a cold inflation pressure. When is cold inflation pressure measured? Wikipedia, Cold inflation pressure. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Preventive Maintenance
  • The oil pressure warning light comes on while a machine is working. Why does the lamp deserve instant attention? US Army TM 9-8000, Principles of Automotive Vehicles (1985), chapter 17. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Preventive Maintenance
  • Oil samples from a machine go to a laboratory on a schedule. What does oil analysis examine? Wikipedia, Oil analysis. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Preventive Maintenance
  • On a construction site, when must vehicles in use be checked for safe brakes, tires, horn, steering and seat belts? OSHA, 29 CFR 1926.601, paragraph (b)(14). Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Preventive Maintenance

Maintain and Repair Hydraulic System 6

  • A cylinder being resealed has a piston area of 12 square inches. At a system pressure of 2,000 psi, what force can it exert while extending? Wikipedia, Hydraulic cylinder. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Hydraulic System; the arithmetic was worked twice
  • A schematic shows a check valve in the line to a cylinder. What does a check valve do? Wikipedia, Check valve. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Hydraulic System
  • In an open center hydraulic circuit, where does the pump flow go while the control valve is centered? Wikipedia, Hydraulic machinery, Hydraulic circuits. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Hydraulic System
  • On a variable displacement axial piston pump, what controls the output from zero to maximum? Wikipedia, Axial piston pump. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Hydraulic System
  • Which hydraulic component converts mechanical power from the engine into hydraulic energy? Wikipedia, Hydraulic pump. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Hydraulic System
  • Which valve limits the pressure in a hydraulic system so that it cannot build to a damaging level? Wikipedia, Relief valve. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Maintain and Repair Hydraulic System

General Shop Practices 5

  • A bolt is marked 1/2-13 UNC. In a Unified thread designation, what does the 13 give? Wikipedia, Unified Thread Standard, Designation. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), General Shop Practices
  • A hole has been drilled for a new threaded stud. Which tool cuts the internal thread in the hole? Wikipedia, Tap and die. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), General Shop Practices
  • A technician chips slag where flying objects are a hazard. Under 29 CFR 1910.133, what must the eye protection provide? OSHA, 29 CFR 1910.133, paragraph (a)(2). Written to NOCTI Heavy Equipment Maintenance and Repair (3046), General Shop Practices
  • A thread-locking compound is put on a bolt before it is run in. How does the compound typically cure? Wikipedia, Thread-locking fluid, Properties. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), General Shop Practices
  • Under 29 CFR 1910.244, what must be legibly and permanently marked on a jack? OSHA, 29 CFR 1910.244, paragraph (a)(1)(ii). Written to NOCTI Heavy Equipment Maintenance and Repair (3046), General Shop Practices

Air Conditioning 3

  • In a cab air conditioning system, what does the condenser do? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 37-8. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Air Conditioning
  • Refrigerant is recovered from a machine before an air conditioning repair. What must be done before it is charged back into the same system? U.S. EPA, Regulatory Requirements for MVAC System Servicing. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Air Conditioning
  • Which air conditioning component collects high-pressure liquid refrigerant and takes moisture out of it? US Army TM 9-8000, Principles of Automotive Vehicles (1985), paragraph 37-3. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Air Conditioning

Heavy Equipment Undercarriage 3

  • A dozer is held up on jacks so that a technician can work under the track frame. What does 29 CFR 1926.600 require before anyone goes under it? OSHA, 29 CFR 1926.600, paragraph (a)(3)(i). Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Heavy Equipment Undercarriage
  • On a track-type undercarriage, what is the main job of the non-powered idler wheel at the far end from the sprocket? Wikipedia, Continuous track, Construction and operation. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Heavy Equipment Undercarriage
  • Which ground engaging tool is a large hook-like shank on the rear of a bulldozer, used to loosen dense material? Wikipedia, Bulldozer. Written to NOCTI Heavy Equipment Maintenance and Repair (3046), Heavy Equipment Undercarriage

How this list was compiled: Our own questions, written to the competency list of the Job Ready Credential Blueprint for Heavy Equipment Maintenance and Repair (code 3046, version 01, copyright 2009) that NOCTI publishes at https://www.nocti.org/wp-content/uploads/2020/10/JRHeavyEquip3046.pdf , read 2026-10-16: a written assessment of 174 questions in 3 hours over ten areas (Maintain and Repair Engine 16%; Maintain and Repair Power Train 10%; Maintain and Repair Electrical System 12%; Maintain and Repair Brake System 11%; Welding 5%; Preventive Maintenance 11%; Maintain and Repair Hydraulic System 11%; General Shop Practices 10%; Air Conditioning 7%; Heavy Equipment Undercarriage 7%), plus a performance assessment of seven jobs. This bank holds 50 in those proportions. Every rule and definition was read on 2026-10-16 on the public page named under its question: OSHA standards in 29 CFR 1910 and the construction equipment rules in 29 CFR 1926 on osha.gov, the EPA page on servicing motor vehicle air conditioning, US Army TM 9-8000, Principles of Automotive Vehicles (1985, the copy at archive.org) and Wikipedia. Every pressure, area and tooth count in a sum is made up for the drill, and each computed answer is arithmetic that was worked twice. Licence: Questions, choices and explanations are original work of this site. TM 9-8000 is a work of the United States Army approved for public release, and no question or example is copied from it.

How it works

This free NOCTI Heavy Equipment Maintenance and Repair practice test has 50 questions of our own, sorted by the ten areas of Job Ready blueprint 3046. It is unofficial and not affiliated with, endorsed by or sponsored by NOCTI.

Read the full guide

Ten areas, in the blueprint's shares

Maintain and Repair Engine is 16% of the written assessment and Electrical System 12%. Brake System, Preventive Maintenance and Hydraulic System are 11% each, Power Train and General Shop Practices 10% each, Air Conditioning and Heavy Equipment Undercarriage 7% each and Welding 5%.

Timed at the real pace

Fifty questions in 52 minutes matches the pace of the written assessment. The blueprint prints no pass mark, so a round ends in a score.

What stays in the shop

The seven performance jobs are not practiced here: testing a cooling system, electrical testing, adjusting valve clearance, setting ring and pinion backlash, identifying brake components, measuring and adjusting a track, and cutting and welding steel.

  • Force is pressure times area: 1,500 psi on a 10-square-inch piston gives 15,000 pounds.
  • OSHA answers cite the paragraph, such as 1926.600(a)(3)(i) for blocking or cribbing a machine held up on jacks.
  • A small gear driving a larger one trades speed for torque by the ratio of their teeth.

Questions and answers

How many questions are on the NOCTI Heavy Equipment Maintenance and Repair test?

The Job Ready blueprint, code 3046, lists 174 written questions with an administration time of 3 hours, given in one, two or three sessions. The seven performance jobs take another 2 hours and 25 minutes.

What is on the NOCTI Heavy Equipment Maintenance and Repair test?

Written questions on the blueprint's competencies, among them hydrostatic power trains, final drives, power shift transmissions, electronic controls, air, wet and hydraulic brakes, shielded metal arc welding, oil sampling, hydraulic schematic symbols, recovering and recharging air conditioning, track tension, and blocking and cribbing.

Does this cover the NOCTI Teacher test for Heavy Equipment Maintenance and Repair?

Largely. The Teacher blueprint, code 5912, prints the same ten areas with 169 questions in 3 hours. Two weights differ by a point: engine is 15% and brake system 12%. Teacher tests are given at a NOCTI-approved Area Test Center.

Where is the NOCTI Heavy Equipment Maintenance and Repair blueprint?

On nocti.org/credentials/blueprints, as a free PDF with the competencies, the share of each area, ten sample questions and a sample job. None of the samples is used or reworded on this page.

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