310S brakes, steering and suspension practice questions.

Five free practice questions on brakes, steering and suspension: block F of the Red Seal 310S Automotive Service Technician exam, about 23 of its 125 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

1. Critical · Diagnoses braking and control systems

   A vehicle's ABS activates during light braking at 10–15 km/h on dry pavement, with the pedal buzzing and a hydraulic pump sound. There are no stored DTCs and the ABS lamp is off. What is the most likely cause?

   1. Low brake fluid level
   2. A faulty ABS hydraulic control unit
   3. A damaged tone ring at one wheel
   4. Worn front brake pads
   Show the answer

   C. Correct. A cracked or debris-packed tone ring, or a sensor pushed away from it by rust build-up, produces a signal that drops out or looks like a locking wheel at low speed. The module reacts by releasing pressure — false activation — but the signal is not bad enough to set a code. Compare all four wheel speeds on the scan tool (or scope them) during a slow roll to find the odd one.

   Why not the others

   A. Low fluid usually turns on the brake warning lamp and can let air in, but it does not make the module think a wheel is locking on dry pavement.

   B. A hydraulic unit fault normally sets a DTC and turns on the ABS lamp. Speed-related false activation with a clean code memory is a signal-quality problem at a wheel.

   D. Worn pads reduce braking and can make noise, but they do not generate false wheel-speed signals. ABS decisions are based on wheel-speed data.

2. Procedural · Repairs braking and control systems

   A technician is installing shoes on a duo-servo (self-energizing) rear drum brake. The primary shoe has a shorter lining than the secondary. How should the shoes be positioned?

   1. Both shoes with the longer lining, discarding the shorter one
   2. Either way, as long as both shoes on the same wheel match
   3. Primary (shorter lining) toward the front, secondary toward the rear
   4. Primary toward the rear, secondary toward the front
   Show the answer

   C. Correct. In a duo-servo brake the primary shoe leads and, in forward braking, its drag is passed through the star-wheel adjuster link to the secondary shoe, which does most of the work — hence the longer lining. Reversing them reduces braking, unbalances the axle and wears the shoes unevenly.

   Why not the others

   A. Shoes are supplied and installed as a matched primary/secondary set; using two secondaries defeats the servo action and the adjuster geometry.

   B. The shoes are not interchangeable in position. Duo-servo geometry depends on the shorter-lined primary shoe being at the front.

   D. That is backwards. The shoe with the shorter lining is the primary and faces forward; the heavily loaded secondary shoe with the longer lining faces the rear.

3. Critical · Diagnoses tires, wheels, hubs and wheel bearings

   A front-wheel-drive car has a growling hum that rises with road speed. On the road test at 80 km/h the noise gets louder when the driver steers gently to the left and quieter when steering gently to the right. What is the most likely source?

   1. A worn outer CV joint
   2. The right front wheel bearing
   3. Tire tread noise from irregular wear
   4. The left front wheel bearing
   Show the answer

   B. Correct. Cornering shifts weight to the outside wheels, so a bearing that gets louder in a left curve is on the right side. Confirm on the hoist with a stethoscope or chassis ears while spinning the wheel, and check for play by rocking the tire at 12 and 6 o'clock.

   Why not the others

   A. A worn outer CV joint clicks or pops in tight turns under power. It does not produce a speed-related growl that changes with lateral load.

   C. Cupped or heel-toe tire wear does make a hum, but it does not change consistently with left/right steering load the way a bearing does. Look at the tires too, but the load-sensitive behaviour points to a bearing.

   D. In a left curve the left wheel is on the inside and unloaded, so a worn left bearing would get quieter, not louder. Load moves to the outside wheel.

4. Procedural · Repairs tires, wheels, hubs and wheel bearings

   A customer's tire has a nail near the centre of the tread, about 50 mm (2 in) in from the shoulder; the hole is roughly 4 mm (5/32 in) in diameter. Which repair is acceptable?

   1. Demount the tire, inspect the inside, and install a combination plug-patch from the inside
   2. Repair it with a plug-patch even though it is on the shoulder, because it is small
   3. Apply an inside patch only, since the hole is small
   4. Insert a string plug from the outside without removing the tire from the wheel
   Show the answer

   A. Correct. The puncture is in the repairable crown area, within the usual 6 mm (1/4 in) limit. An approved repair means dismounting, inspecting the interior for damage from running under-inflated, reaming and cleaning the injury, and installing a plug-patch (or a plug and patch) that fills the hole and seals the inner liner. Then re-balance the assembly.

   Why not the others

   B. Shoulder and sidewall repairs are not permitted regardless of size, because the area flexes too much. Here the hole is in the tread crown, so it is repairable; had it been in the shoulder the tire would be replaced.

   C. A patch seals the liner but leaves the hole open to moisture, which rusts the steel belts from inside. The injury must be filled as well as sealed.

   D. An external plug alone does not seal the inner liner and does not allow inspection of the inside for run-flat damage. It is considered a temporary repair at best and is not an approved permanent repair.

5. Procedural · Diagnoses steering, suspension and control systems

   During the pre-alignment inspection, the technician finds the left rear ride height 25 mm (1 in) lower than the right and the specification. Tires, pressures and suspension joints are all good. What should be done before aligning the vehicle?

   1. Correct the ride height (sagged spring) and then measure the angles
   2. Compensate by setting extra camber on that side
   3. Align the vehicle as it sits and note the ride height on the work order
   4. Adjust rear toe only, since ride height affects only toe
   Show the answer

   A. Correct. Ride height sets the position of every suspension link, so camber, caster and toe all change with it. Aligning a sagged corner just locks in a compromised setting that changes again if the spring is later replaced. Correct the cause first, then align.

   Why not the others

   B. Adjusting the angles to hide the sag leaves the geometry wrong through the suspension's travel and gives poor handling and tire wear. Fix the ride height; the angles will largely correct themselves.

   C. Alignment specifications are published for the vehicle at correct ride height. Recording the sag does not make the alignment valid.

   D. Ride height affects camber, caster and toe. Setting one angle on a sagged corner does not address the problem.

02Answer key

03What block F covers

This block covers brakes, steering, suspension, tires, wheels and wheel bearings. It includes wheel alignment angles, ball joints and tie rods, air suspension and power steering, disc and drum brakes, ABS and electric parking brakes, brake fluid and lines, tire repair, TPMS sensors and relearns, and ADAS camera and radar calibration after suspension or collision work.

The Red Seal Occupational Standard names this block “Diagnoses and repairs steering, suspension, braking and control systems, tires, hubs and wheel bearings”. It carries 18.4% of the exam, about 23 of the 125 questions, split across two tasks. The share column is each task's weight within the block, as the standard publishes it.

04What the questions turn on

Alignment angles and order

A vehicle pulls toward the side with more positive camber. Too little positive caster causes wander and poor return to centre. Set camber and caster first and toe last, because adjusting the first two changes toe.

Rotor thickness and runout

Pedal pulsation comes from rotor thickness variation, and lateral runout is what wears it in, often from rust or debris on the hub face. Measure runout with the rotor clamped to the hub by torqued wheel nuts.

Brake pedal symptoms

A pedal that slowly sinks under steady pressure with no fluid loss and no external leak means the master cylinder is bypassing internally. A low pedal that pumps up on rear drum brakes points to self-adjusters that are not working.

Calibrate after the work

ADAS camera and radar calibration needs thrust angle, tire pressures and ride height in spec first. After toe is set, the steering angle sensor needs its zero point recalibrated, or stability control flags the signal and switches off.

05The other blocks

The 310S exam has eight blocks. Each has its own page of free questions:

The 310S Automotive Service 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.