1. Aftertreatment System
A system in diesel engines that reduces emissions using components like the DPF and SCR. It removes soot, NOx, and other pollutants before exhaust exits the vehicle.
2. Air Brake System
A braking system that uses compressed air instead of hydraulic fluid, common in heavy-duty trucks and trailers. It provides consistent braking power and safety under heavy loads.
3. Air Compressor
A mechanical device that supplies pressurized air to operate brakes, suspension, and tools on heavy trucks. It’s essential for air brake and pneumatic systems.
4. Alignment
Adjusting a vehicle’s suspension and wheel angles to factory specifications for even tire wear and stable steering. Misalignment causes handling issues and tire damage.
5. Alternator
A key electrical component that charges the battery and powers a truck’s electrical systems when the engine is running. A failing alternator can cause battery drain and power loss.
6. Anti-Lock Braking System (ABS)
An electronic safety system that prevents wheels from locking during hard braking, helping maintain steering control. Mandatory in most commercial vehicles.
7. Axle Shaft
A steel rod that transfers torque from the differential to the wheels, driving the truck forward. Damage can cause vibration, noise, or total loss of motion.
8. Backpressure
Resistance in an exhaust system that affects engine performance and fuel economy. Excess backpressure often signals a clogged DPF or exhaust restriction.
9. Battery Load Test
A diagnostic test that measures a battery’s ability to maintain voltage under load. It helps determine if the battery can reliably start a heavy-duty engine.
10. Bearing Failure
The breakdown of rotating components due to contamination, overheating, or lubrication loss. Common in engines, transmissions, and wheel hubs.
11. Blow-by
The leakage of combustion gases past piston rings into the crankcase. Excessive blow-by indicates worn engine components or poor compression.
12. Brake Chamber
A component in an air brake system that converts air pressure into mechanical force to apply the brakes. It’s vital for safe stopping power in trucks and trailers.
13. Brake Lining
The friction material on brake shoes or pads that contacts the drum or rotor. Worn linings reduce braking efficiency and can lead to CVIP failure.
14. Bulkhead
A rigid partition in a trailer or tank truck that prevents cargo movement or provides structural support. Essential for load stability and safety.
15. Camshaft
A rotating shaft inside an engine that opens and closes intake and exhaust valves in sync with piston movement. Cam wear can cause power loss or rough idle.
16. Check Engine Light
A dashboard warning indicating an engine fault or emissions problem. Diagnostic tools read stored error codes to identify the cause.
17. Coolant Leak
Loss of engine coolant due to a damaged hose, gasket, or radiator. Leads to overheating and potential engine failure if not repaired promptly.
18. Crankcase Ventilation System
A system that removes gases and vapors from the crankcase, preventing pressure buildup and oil contamination. Clogged systems can cause oil leaks and smoke.
19. CVIP (Commercial Vehicle Inspection Program)
Alberta’s mandatory inspection program ensuring commercial trucks and trailers meet safety standards. DMR Diesel is a certified CVIP inspection facility.
20. Cylinder Head
The upper section of an engine that houses valves, injectors, and combustion chambers. Warping or cracking can cause coolant leaks or loss of compression.
21. DEF (Diesel Exhaust Fluid)
A urea-based solution used in the SCR system to reduce nitrogen oxide (NOx) emissions from diesel engines. Stored in a separate tank and injected into exhaust gases.
22. Differential
A gearbox that allows drive wheels to rotate at different speeds while cornering. Worn gears or low fluid can cause whining noises or poor traction.
23. DPF (Diesel Particulate Filter)
A component that traps and burns soot from diesel exhaust to reduce emissions. Requires regular regeneration or cleaning to maintain performance.
24. Drive Shaft
A rotating tube that transmits torque from the transmission to the differential. Imbalance or worn joints cause vibration and noise during acceleration.
25. Dual Axle Trailer
A trailer equipped with two axles to distribute weight evenly and improve stability. Common in heavy haul and commercial freight applications.
26. EGR (Exhaust Gas Recirculation)
A system that recirculates a portion of exhaust gases back into the engine’s intake to lower combustion temperatures and reduce NOx emissions.
27. Electrical Harness
A bundle of wires and connectors that delivers power and signals to different components of a truck or machine. Damage can cause shorts, warning lights, or system failure.
28. Engine Block Heater
A device that preheats the engine coolant or oil before startup, helping diesel engines start more easily in cold weather. Commonly used in Alberta winters.
29. Engine Overhaul
A complete disassembly and rebuild of a diesel engine to restore it to near-new condition. It includes inspection, cleaning, machining, and replacement of worn parts.
30. Engine Rebuild Kit
A set of components such as pistons, rings, bearings, and gaskets used to restore an engine’s performance during a rebuild or overhaul.
31. Engine Timing
The synchronization of camshaft and crankshaft movement that ensures proper valve and fuel injector operation. Incorrect timing can cause poor performance or engine damage.
32. Exhaust Leak
A hole or crack in the exhaust system that allows gases to escape before they’re treated by aftertreatment components. Often causes increased noise or emissions faults.
33. Exhaust Manifold
A cast or tubular component that collects exhaust gases from the engine’s cylinders and directs them into the turbocharger or exhaust pipe.
34. Fan Clutch
A temperature-controlled coupling that engages or disengages the engine fan. It helps regulate engine temperature and reduce fuel consumption when cooling isn’t needed.
35. Fifth Wheel
A coupling device that connects a tractor unit to a semi-trailer, allowing it to pivot for turning. It’s a critical safety component in heavy-haul trucking.
36. Fleet Maintenance
A scheduled service program designed to keep multiple commercial vehicles in safe, efficient operating condition. It includes inspections, oil changes, and repairs.
37. Fuel Filter
A filter that removes dirt, water, and contaminants from diesel fuel before it enters the injectors. Regular replacement prevents fuel system damage.
38. Fuel Injector
A precision component that delivers pressurized diesel fuel into the combustion chamber. Dirty or failing injectors can cause misfires, poor fuel economy, or rough running.
39. Fuel Pump
A mechanical or electronic device that transfers fuel from the tank to the engine. Low pressure or failure can cause stalling or hard starting.
40. Fuel System Bleeding
The process of removing trapped air from a diesel engine’s fuel system to restore proper flow and prevent starting issues after maintenance or filter replacement.
41. Gear Oil
A thick lubricant used in transmissions, differentials, and gearboxes to reduce friction and wear on moving parts. Must be replaced periodically for smooth operation.
42. Grease Fitting (Zerk Fitting)
A small metal nozzle that allows a grease gun to lubricate bearings or joints. Proper greasing extends component life and prevents mechanical wear.
43. Ground Strap
A metal connector that grounds the electrical system to the truck’s chassis. A corroded or loose strap can cause intermittent electrical problems.
44. Head Gasket
A seal between the engine block and cylinder head that keeps combustion gases, coolant, and oil separate. A blown head gasket can cause overheating and loss of power.
45. Heavy-Duty Truck
A commercial vehicle with a gross vehicle weight rating (GVWR) over 26,000 pounds, designed for hauling large loads and industrial transport.
46. High-Pressure Fuel Pump
A pump that delivers fuel at extremely high pressure to injectors in modern diesel engines. Failure can lead to performance loss or injector damage.
47. Horsepower
A unit of measurement for engine power, indicating how quickly work can be done. Higher horsepower allows for greater load capacity and acceleration.
48. Hydraulic Cylinder
A mechanical actuator that uses pressurized fluid to produce linear motion or force, commonly found in construction and off-road equipment.
49. Hydraulic Leak
The loss of hydraulic fluid due to worn seals, cracked hoses, or loose fittings. Can lead to reduced system pressure and unsafe equipment operation.
50. Hydraulic Pump
A component that moves hydraulic fluid through a system to power machinery such as lifts, loaders, or excavators. Essential for off-road and industrial applications.
51. Idle Control Valve
A device that manages engine idle speed by regulating air intake when the throttle is closed. A faulty valve can cause rough idling or stalling.
52. Ignition Switch
The electrical switch that activates the starter motor and powers the vehicle’s systems. Worn contacts can cause intermittent starting or accessory power issues.
53. Injector Cup
A sleeve inside the cylinder head that seals and supports the fuel injector. Damaged cups can lead to fuel leakage into the cooling system.
54. Injector Pulse
The timed signal that controls how long a fuel injector stays open during each engine cycle. Incorrect pulses can cause poor fuel economy or misfires.
55. Intake Manifold
A cast or molded component that distributes air evenly to each cylinder for combustion. Leaks or cracks can cause rough running and reduced power.
56. Intercooler
A heat exchanger that cools compressed air from the turbocharger before it enters the engine, improving power and efficiency.
57. Jackshaft
A rotating shaft that transfers motion between two separate components, often used in drivetrains or auxiliary systems.
58. Jake Brake (Engine Brake)
A braking system that uses engine compression to slow down a truck without relying solely on wheel brakes. Common in highway transport.
59. Jumper Cable
A pair of insulated cables used to connect a dead battery to a charged one for emergency starting.
60. Kingpin
The main pivot point that connects a semi-trailer to a tractor’s fifth wheel. Worn kingpins can cause steering instability and coupling issues.
61. Leaf Spring
A suspension component made of layered steel strips that support vehicle weight and absorb shock. Broken springs can affect ride height and handling.
62. Lift Axle
An auxiliary axle that can be raised or lowered to distribute weight as needed for heavy loads. Helps improve traction and reduce tire wear.
63. Load Rating
The maximum weight capacity a tire or component can safely support. Exceeding this rating can lead to premature failure or unsafe handling.
64. Load Securement
The method of tying down or restraining cargo in a truck or trailer to prevent shifting during transport. Required under commercial safety laws.
65. Locking Differential
A mechanism that forces both drive wheels to rotate at the same speed for better traction on slippery or uneven terrain.
66. Low Coolant Sensor
A sensor that monitors coolant levels in the engine. If triggered, it indicates a leak or loss of coolant that can cause overheating.
67. Low Oil Pressure Warning
A dashboard alert that indicates oil pressure is below safe operating levels. Running the engine under low oil pressure can cause catastrophic damage.
68. Lubrication System
A system that circulates oil through an engine to reduce friction, clean components, and carry away heat. Regular oil changes keep it functioning properly.
69. Lug Nut Torque
The specified tightness applied to wheel nuts to ensure proper clamping force. Incorrect torque can lead to wheel loss or brake distortion.
70. Lumens
A measurement of light output used to rate headlights or work lights. Higher lumens indicate brighter illumination, important for night operations.
71. Load Sensor Valve
A component in an air brake system that adjusts braking pressure based on vehicle load, improving stopping performance and safety.
72. Leveling Valve
A valve in an air suspension system that maintains correct ride height by adding or releasing air in the airbags.
73. Lift Gate
A hydraulic platform mounted on the rear of a truck for lifting cargo to or from the bed. Common in delivery and service vehicles.
74. Lock Pin
A removable metal pin used to secure mechanical parts in place, such as trailer hitches or equipment arms.
75. Lowboy Trailer
A trailer with a lower deck height designed for hauling tall or heavy equipment such as excavators and bulldozers.
76. Maintenance Schedule
A planned timeline for performing regular inspections, oil changes, and component replacements to prevent breakdowns and extend equipment life.
77. Manifold Pressure Sensor
A sensor that measures air pressure in the intake manifold to help the engine control fuel delivery and boost pressure.
78. Mechanical Failure
The breakdown of any moving part or system due to wear, damage, or lack of maintenance. Early detection prevents costly downtime.
79. Motor Oil Viscosity
The measure of how thick or thin motor oil is at different temperatures. Correct viscosity ensures proper lubrication and engine protection.
80. Muffler
A component in the exhaust system that reduces engine noise. A damaged or rusted muffler can cause loud operation and reduced performance.
81. Multimeter
A diagnostic tool used to measure voltage, current, and resistance in electrical circuits. Essential for troubleshooting electrical issues.
82. Neutral Safety Switch
A safety feature that prevents a truck from starting unless the transmission is in neutral or park.
83. Oil Filter
A device that removes contaminants from engine oil, protecting moving parts from premature wear. Regular replacement is part of every service.
84. Oil Pressure Sensor
A sensor that monitors the oil pressure and sends readings to the dashboard. Failure can trigger false alerts or hide real oil problems.
85. Overheating
A condition where engine temperature exceeds safe limits, often caused by coolant leaks, radiator blockages, or faulty thermostats.
86. Overload
Operating a truck or trailer beyond its designed weight capacity, which can cause brake failure, tire blowouts, or frame damage.
87. Piston Rings
Metal rings fitted around the piston that seal the combustion chamber, control oil consumption, and maintain compression. Worn rings can cause blow-by or blue smoke.
88. Power Steering Pump
A hydraulic pump that provides pressure to assist steering effort. Failure can cause stiff steering or whining noises during turns.
89. Preventive Maintenance (PM)
Scheduled service work designed to detect and correct potential problems before they lead to breakdowns. Key to long-term fleet reliability.
90. Pressure Relief Valve
A safety valve that opens when pressure in a system exceeds safe limits, preventing component damage or hydraulic failure.
91. PTO (Power Take-Off)
A mechanical device that transfers engine power to auxiliary equipment, such as dump beds, winches, or hydraulic pumps.
92. Pulling to One Side
A steering issue that occurs when brake, suspension, or alignment problems cause uneven resistance between wheels.
93. Pump Motor Assembly
A combined motor and pump unit used in hydraulic or fuel systems to move fluid under pressure.
94. Push Rod
A metal rod in an engine that transfers motion from the camshaft to the valves in an overhead valve system.
95. Pyrometer
A gauge that measures exhaust gas temperature to monitor engine performance and prevent overheating of turbochargers or pistons.
96. Radiator
A heat exchanger that cools engine coolant by passing it through finned tubes. Essential for regulating operating temperature.
97. Regeneration (DPF Regen)
The process of burning off soot collected in the diesel particulate filter to restore exhaust flow and efficiency.
98. Relay Switch
An electrically controlled switch that allows a small current to control a larger one. Common in lighting, starter, and accessory circuits.
99. Retarder
A secondary braking system used in heavy-duty trucks to slow down the vehicle without using friction brakes, reducing wear and heat.
100. RPM (Revolutions Per Minute)
A measure of how fast the engine crankshaft rotates. Monitoring RPM helps maintain efficiency, avoid over-revving, and optimize fuel economy.
