Five free practice questions on safety, tools and shop skills: block A of the Red Seal 310T Truck and Coach Technician exam, about 8 of its 135 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.
01The questions
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A technician is about to weld a cracked bracket on the frame of a truck with an electronically controlled engine and ABS. Which step protects the vehicle's electronic components during the weld?
- Weld at a lower amperage so less current reaches the electronics.
- Turn the ignition off and leave the batteries connected as a ground.
- Disconnect the batteries and clamp the ground close to the weld.
- Connect the ground clamp to the battery negative terminal.
Show the answer
C. Correct. Welding current takes the easiest path to the ground clamp; a clamp placed far away can route current through bearings, harnesses and control modules. Disconnecting the batteries and, where the manufacturer specifies, unplugging module connectors removes the electronic components from the circuit. The RSOS requires the vehicle to be prepared for welding according to the manufacturer's service information specifically to prevent damage to electronic components.
Why not the others
A. Any welding current that finds its way through a module can damage it; reducing amperage makes a poor weld without removing the path. Protection comes from controlling where the current flows, not how much.
B. Ignition off does not isolate the modules from the vehicle's ground path, and leaving the batteries connected makes them part of the circuit the welding current can find. Batteries are disconnected, not used.
D. Grounding at the battery guarantees the welding current travels the full length of the chassis through every ground strap, bearing and harness connection between the weld and the battery. The clamp goes as close as practical to the weld, on clean bare metal.
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A technician raises the rear of a straight truck with a hydraulic floor jack to replace a drive-axle hub seal. Before getting under the vehicle, what must be in place?
- A second technician watching the jack while the work is done.
- The parking brake applied and the transmission in gear.
- Rated support stands under the axle and the front wheels chocked.
- The jack's pressure release closed and the handle locked.
Show the answer
C. Correct. The load is transferred to support stands rated for the weight, placed on a solid level surface at the manufacturer's support points, and the wheels still on the ground are chocked so the truck cannot roll. The jack is then only a backup. The RSOS lists jack/support stands and wheel chocks as safety equipment for exactly this reason.
Why not the others
A. A spotter cannot react fast enough to stop a falling vehicle, and does nothing to hold the load. The control that prevents the crush hazard is mechanical support, not observation.
B. Parking brake and gear selection help prevent rolling, but they do not support a raised vehicle. With the drive axle in the air, the parking brake on that axle holds nothing, and chocks on the grounded wheels plus support stands are still required.
D. A closed release valve keeps the jack extended, but a jack is a lifting device, not a supporting device. Seal failure or a shifted load can drop it without warning. Nothing about the jack itself makes it safe to work under.
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A driver reports that a highway tractor pulls normally in the yard but loses power on grades and at highway speed under load, with no fault codes stored. The engine idles smoothly. Which service item is the most likely cause?
- Contaminated diesel exhaust fluid.
- A restricted engine oil filter.
- A restricted fuel filter.
- A plugged cabin air filter.
Show the answer
C. Correct. A plugged fuel filter passes enough fuel for idle and light load but cannot supply the volume the engine demands at full power, so the symptom appears only under load and at speed. The RSOS expects the technician to recognize performance issues and symptoms related to plugged filters. Checking fuel restriction or pressure at the filter, then inspecting the element for debris, confirms it and tells the technician about the condition of the tank and lines.
Why not the others
A. Poor DEF quality triggers aftertreatment fault codes and an inducement (derate) sequence that the driver would notice at any load, and codes would be stored. No codes and a smooth idle point away from the aftertreatment system.
B. A plugged oil filter opens its bypass valve and the engine keeps running on unfiltered oil; it does not reduce power under load. Its symptom is low oil pressure and accelerated wear, not a load-dependent power loss.
D. The cabin filter serves the HVAC system and has no connection to engine performance. A plugged cabin filter reduces airflow to the cab, nothing more.
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A journeyperson has demonstrated a wheel-bearing adjustment to an apprentice, who has since performed it correctly several times while the journeyperson watched each step. What is the appropriate next stage of practice?
- Move on to teaching a different task, since this one has been demonstrated.
- Keep the apprentice under direct step-by-step supervision until the end of their term.
- Let the apprentice perform the task with limited independence, checking the result.
- Assign the apprentice to adjust all the bearings in the shop unsupervised.
Show the answer
C. Correct. The RSOS describes practice conditions as guided, then limited independence, then full independence, and the outcome sought is that performance improves with practice to the point where the task can be done with little supervision. Having done it correctly several times under guidance, the apprentice moves to doing it alone with the journeyperson verifying the result, such as checking endplay, before advancing to full independence.
Why not the others
A. Demonstration is only the start of learning a skill. Skills are built by practice with feedback and assessed for progress; changing topics before the apprentice has practised with increasing independence leaves the skill half-learned.
B. Practice conditions are meant to progress. Holding an apprentice at the guided stage after they have shown they can do the task denies them the independence that builds competence, and it ties up the journeyperson unnecessarily.
D. Jumping straight to full independence on a safety-critical wheel-end task skips the stage where the result is still checked. Several correct guided attempts justify limited independence, not an unverified workload.
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A technician is about to load an updated calibration file into an engine control module using the manufacturer's diagnostic software. Which step comes first?
- Clear all stored fault codes so the module starts clean.
- Verify the module's software version against the OEM file.
- Start the engine so the module is fully awake before programming.
- Disconnect the batteries to protect the module during the write.
Show the answer
B. Correct. The RSOS states the sequence directly: the software version is verified, the file is downloaded from the manufacturer, then uploaded to the controller. Confirming the current version against the manufacturer's release ensures the right calibration is going into the right module. A stable power supply is maintained throughout so the write is not interrupted.
Why not the others
A. Clearing codes erases diagnostic history that may be needed to confirm the update addresses the fault, and it has nothing to do with whether the correct file is being loaded. Codes are recorded and dealt with as part of diagnosis, not wiped before programming.
C. Programming is done with the engine off and the ignition in the position the manufacturer specifies. A running engine adds electrical noise and load, and the manufacturer's procedure will state the required conditions.
D. Programming requires the module to be powered and communicating. Removing battery power stops the process; the correct precaution is the opposite, a stable voltage supply so the write cannot be interrupted.
02Answer key
| Question | Answer | Sub-task |
|---|---|---|
| Q1 | C | Uses welding and cutting equipment |
| Q2 | C | Uses personal protective equipment (PPE) and safety equipment |
| Q3 | C | Services filters |
| Q4 | C | Uses mentoring techniques |
| Q5 | B | Uses electronic devices and systems for diagnostics and programming |
03What block A covers
This block covers the shop skills behind every other task on a truck or coach. It includes WHMIS and safety data sheets, PPE, jack stands and wheel chocks, shop cranes and sling angles, high-voltage safety on hybrid and electric vehicles, torque wrenches, welding on a chassis, ECM programming, service bulletins, oil analysis, filters, bearings, fasteners, and mentoring apprentices.
The Red Seal Occupational Standard names this block “Performs common occupational skills”. It carries 5.9% of the exam, about 8 of the 135 questions, split across four tasks. The share column is each task's weight within the block, as the standard publishes it.
| Task and its sub-tasks | Share of block |
|---|---|
| Performs safety-related functions Maintains safe work environment; Uses personal protective equipment (PPE) and safety equipment; Implements specific safety protocols for hybrid and electric vehicles (EV) | 28% |
| Uses and maintains tools and equipment Uses hand, power, measuring, testing, and diagnostic tools; Uses shop equipment; Uses hoisting, lifting and staging equipment; Uses welding and cutting equipment; Uses electronic devices and systems for diagnostics and programming | 32% |
| Performs routine work practices Uses documentation and reference materials; Maintains fluids and lubricants; Services hoses, tubing and fittings; Services filters; Services bearings and seals; Uses fasteners and sealing devices | 28% |
| Uses communication and mentoring techniques Uses communication techniques; Uses mentoring techniques | 12% |
04What the questions turn on
Proving zero voltage
Removing the service disconnect and waiting is not proof. Test the meter on a known source, measure the HV terminals for zero volts, then test the meter again. Insulating gloves are air-tested before every use, and a glove that loses air is pulled from service.
Crane reach and sling angles
A shop crane's rated load drops as the boom extends, so read the load tag at the reach the job needs. On a two-leg sling with each leg at 30 degrees to horizontal, each leg carries the whole load.
Reading an oil sample
Silicon in used oil is the signature of dirt getting in, and iron rising with it is the abrasive wear that dirt causes. Check the intake for a leaking duct or a poorly seated air filter, then resample after the repair.
Welding on the truck
Before welding a bracket, disconnect the batteries and clamp the ground close to the weld so current cannot route through modules and bearings. A crack in a frame rail is different: follow the manufacturer's procedure and refer it to a certified welder.
05The other blocks
The 310T exam has 11 blocks. Each has its own page of free questions:
The 310T Truck and Coach Technician practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.