The Fleet Tech Challenge Trivia: Quiz

A tire pressure monitoring system (TPMS) is a system that monitors the air pressure in the tires of a vehicle. It uses a warning light or message to alert the driver when the tire pressure is low. It is often referred to as a TPMS. However, it cannot automatically stop a leak in a tire. The purpose of a TPMS is to monitor the tire pressure and provide a warning to the driver, but it does not have the ability to fix or repair a leak in the tire. To diagnose any issues with the TPMS, an appropriate scan tool is required.

Tech B is correct. Bench bleeding a master cylinder does make bleeding the brakes on the vehicle easier. Bench bleeding involves filling the master cylinder with brake fluid and then using a tool to pressurize the fluid, which helps remove any air bubbles trapped in the cylinder. This ensures that when the master cylinder is installed in the vehicle, there is no air in the brake lines, making the brake bleeding process quicker and more effective.

Tech B is correct. Brake shoes should be replaced in axle sets. This is because brake shoes wear out over time and it is important to maintain balanced braking performance on both sides of the axle. Replacing only one brake shoe can result in uneven braking and potential safety issues. Additionally, brake shoes that have been saturated with brake fluid may have compromised their effectiveness and should not be reused.

Heavy pulling of a vehicle to either the left or the right can be caused by mismatched tire sizes or pressures, out-of-alignment wheels, or a dragging front brake assembly. Nitrogen filled tires, however, do not have any direct impact on the steering or pulling of a vehicle. The use of nitrogen instead of regular air in tires is primarily done to maintain more consistent tire pressure and reduce the risk of tire failure due to moisture or temperature changes. Therefore, nitrogen filled tires are not a likely cause of heavy pulling in a vehicle.

Tech B is correct. When checking a tie-rod, any side-to-side movement in the joint indicates that the tie-rod is bad. Rotational movement, as suggested by Tech A, may not necessarily indicate a problem with the tie-rod. Therefore, Tech B's statement is more accurate in determining the condition of the tie-rod.

In many rear-wheel drive vehicles, the wheel bearings are lubricated with gear oil that also lubricates the differential assembly. Gear oil is specifically designed to withstand the high pressures and temperatures generated by the gears in the differential. It provides excellent lubrication and helps to reduce friction and wear on the bearings and gears. Using engine oil, automatic transmission fluid, or compressor lube would not be suitable for this purpose as they are not formulated to handle the unique demands of the differential and wheel bearings.

Valve springs are responsible for closing the intake valves in the cylinder head. These springs exert pressure on the valves, ensuring that they remain closed when needed. When the piston moves downward during the intake stroke, the intake valves open against the force of the valve springs, allowing air and fuel to enter the combustion chamber. However, when the piston moves back up during the compression stroke, the valve springs push the intake valves closed, preventing any backflow of gases into the intake manifold.

A green valve stem cap on tires on recent model-year vehicles indicates that the tires are filled with nitrogen. Nitrogen is commonly used as an alternative to regular air in tires because it has several advantages. Nitrogen is less likely to leak through the tire rubber, resulting in more consistent tire pressure over time. It also helps to reduce oxidation and corrosion within the tire, leading to longer tire life. Additionally, nitrogen-filled tires can provide better fuel efficiency and improved handling.

Tech A is correct. Play in the steering system generally results from worn ball sockets and bushings. This means that there is excessive movement or looseness in the steering components, which can lead to a lack of responsiveness and precision in steering. On the other hand, Tech B's statement about tire pressure being the cause of hard steering is incorrect. Hard steering is typically caused by problems with the power steering system, such as low fluid levels or a malfunctioning pump.

Both Tech A and Tech B are correct. Measuring rotors for thickness variation (parallelism) is important as it ensures that the rotor is uniform in thickness, which is crucial for proper braking performance. On the other hand, measuring rotors for lateral runout is also necessary as it checks for any wobbling or unevenness in the rotor's surface, which can cause vibrations and uneven braking. Therefore, both measurements are essential for ensuring the proper functioning of the rotors.

Technician B is correct. Feathering of the tire tread is indeed most commonly a result of excessive toe-in or toe-out. When there is excessive toe-in or toe-out, the tires are not aligned properly and tend to scrub against the road surface, causing the feathering pattern. On the other hand, wear on the center of the tread is usually caused by over-inflation of the tire, not under-inflation as stated by Technician A.

Toe-out on turns is not the relative toe setting of the rear wheels as the vehicle turns. Toe-out on turns refers to the situation where the front wheels are set to turn slightly outward during a turn, which helps to improve stability and reduce understeer. The relative toe setting of the rear wheels as the vehicle turns is not specifically mentioned in the given statements.

Technician B is correct. Packing a wheel bearing assembly involves filling the bearing with grease using a bearing packer. This ensures that the entire bearing is lubricated properly and helps to prevent premature wear and damage. Smearing grease around the outside of the bearing, as suggested by Technician A, does not effectively lubricate the bearing and may lead to inadequate lubrication and potential failure.

When installing a new oil filter, it is a good idea to wipe a small amount of oil on the new filter gasket. This helps to create a better seal between the filter and the engine, preventing any oil leaks. The oil also helps to lubricate the gasket, making it easier to remove the filter during the next oil change. Applying contact cement, gasket sealer, or installing the rubber gasket dry would not provide the same benefits and could potentially cause issues such as leaks or difficulty in removing the filter.

Both Technician A and Technician B are correct. A leaky radiator cap can cause the engine to overheat because it can allow coolant to escape, leading to a decrease in coolant levels and an increase in engine temperature. Similarly, a thermostat stuck closed can also cause the engine to overheat because it prevents coolant from circulating properly, leading to a buildup of heat in the engine.

A cogged belt is typically used to drive the camshaft. Unlike a V belt or serpentine belt, which have smooth surfaces, a cogged belt has teeth that mesh with the pulley's grooves, providing a better grip and preventing slippage. This is crucial for the camshaft, as it needs to maintain precise timing and synchronization with the engine's valves. The teeth on the cogged belt ensure a more reliable transfer of power, making it the ideal choice for driving the camshaft.

Both technicians are correct. In scope testing, the vertical axis of the screen represents voltage, while the horizontal axis represents time. This allows technicians to visually analyze the relationship between voltage and time, making it easier to identify any abnormalities or patterns in the electrical signals being tested.

Both Tech A and Tech B are correct. Some TPMS sensors are indeed part of the tire's valve stem, while others are held on by a large band that fits around the center of the rim.

Technician B is correct. A vehicle's charging system should typically run at around 13.5 to 14.5 volts when the engine is running. A voltage of 17.2 volts indicates a faulty voltage regulator, which is responsible for regulating the voltage produced by the alternator. If the voltage regulator is faulty, it can cause the charging system to output a higher voltage, potentially damaging the vehicle's electrical components. Therefore, Technician B's statement about a faulty voltage regulator causing the high voltage condition is accurate.

Fuses prevent circuit damage by stopping excessive current flow. When the current in a circuit exceeds the rated value of the fuse, the fuse wire inside it melts, creating an open circuit and interrupting the flow of current. This protects the circuit and its components from damage caused by overloading or short circuits. By stopping excessive current flow, fuses ensure that the electrical system operates within safe limits and prevents overheating, fires, and other hazards.

Air in the brake lines can cause a spongy brake pedal. When air enters the brake lines, it can compress and create a soft or spongy feeling when the brake pedal is pressed. This can result in a longer stopping distance and a decrease in braking efficiency. The presence of air in the brake lines can also lead to a loss of brake pressure, which can be dangerous and affect the overall performance of the braking system. Therefore, it is important to regularly bleed the brake lines to remove any air and ensure proper brake function.

Tech A is correct. Most brake drums are designed to be machined if minor surface issues are present. This means that instead of replacing the entire brake drum, it can be resurfaced to remove any imperfections and restore its smoothness. Tech B's statement is incorrect because machining the brake drum larger than specifications can compromise its integrity and performance.

The aspect ratio of a tire refers to the ratio of its height to its width. This means that the height of the tire is a certain percentage of its width. For example, if a tire has an aspect ratio of 60, it means that the height of the tire is 60% of its width. This aspect ratio is important because it affects the overall performance and handling of the tire. A lower aspect ratio generally means better handling and cornering abilities, while a higher aspect ratio offers a more comfortable ride.

Lateral runout refers to the amount of deviation or wobbling of the disc brake rotor as it rotates. When a disc brake rotor has lateral runout, it means that it is not perfectly flat or centered, causing the brake pads to make uneven contact with the rotor surface. This can result in vibrations, uneven braking, and decreased braking performance. Therefore, if the disc brake rotor is out of specification in terms of lateral runout, it needs to be corrected or replaced to ensure proper braking function.

Technician B is correct. Oil filters should only be installed by hand. Using a filter wrench to tighten the oil filter can lead to over-tightening, which can cause the filter to become stuck and difficult to remove during the next oil change. Hand tightening ensures that the filter is secure but not overly tightened, allowing for easier removal in the future.

Excessive disc brake rotor thickness variation will cause brake pedal pulsation. When the rotor thickness varies, it can create uneven contact between the brake pads and the rotor. This uneven contact causes the brake pedal to pulsate or vibrate when the brakes are applied. This pulsation is felt by the driver and indicates a problem with the braking system. It is important to address this issue as it can affect the performance and safety of the vehicle's braking system.

An interference engine is a term used to describe an engine in which the valves and piston occupy the same space in the combustion chamber at different times. If the timing belt breaks in an interference engine, the valves and piston can collide, causing significant damage to the engine. This is because the timing belt is responsible for synchronizing the movement of the valves and piston. In contrast, a freewheeling engine allows the valves and piston to operate independently, so if the timing belt breaks, there is no risk of collision. The terms "valve in piston engine" and "collision engine" are not commonly used to describe this specific scenario.

Disconnecting the ignition system or fuel system would prevent the engine from starting. The ignition system is responsible for creating the spark that ignites the fuel in the engine cylinders, while the fuel system is responsible for delivering fuel to the engine. If either of these systems is disconnected, the engine will not receive the necessary spark or fuel to start and run.

A refractometer test is not used to test fuel pump performance. A refractometer is a device used to measure the refractive index of a substance, which is not relevant to testing fuel pump performance. On the other hand, the scan tool test, pressure/volume test, and lab scope test are commonly used methods to assess the functionality and efficiency of a fuel pump.

The hydraulic brake system is responsible for transmitting the pressure from the brake pedal to the brake pads or shoes, which then apply pressure to the rotors or drums to slow down or stop the vehicle. Brake hoses, disc brake calipers, and wheel cylinders are all components of the hydraulic brake system as they play a crucial role in the transmission and application of hydraulic pressure. However, the parking brake assembly is not a part of the hydraulic brake system. The parking brake assembly is a separate system that is used to mechanically hold the vehicle in place when parked.

Tech A is correct because thinner rotors have less material to absorb and dissipate heat, causing them to overheat more quickly. This can lead to brake fade, which is the loss of braking power due to overheating. On the other hand, Tech B's statement about brake pedal pulsation being caused by air in the hydraulic system is incorrect. Brake pedal pulsation is usually caused by unevenly worn brake rotors or warped rotors, not air in the hydraulic system.

The pickle fork tool is commonly used for separating or removing rod ends. It is designed to fit between the joint and the connecting part, allowing for easy removal without causing damage. This tool is specifically designed for this purpose and is not typically used for checking circuit continuity, removing pitman arms, or centering clock springs.

An open circuit refers to a circuit where there is a break in the wire, causing a discontinuity in the flow of current. In this case, the correct answer is "A break in the wire," which accurately describes an open circuit. When there is a break in the wire, the circuit is incomplete, and electricity cannot flow through it. This can happen due to various reasons such as a damaged wire or a loose connection.

Technician A is correct. A higher than normal voltage drop can indeed indicate high resistance. When resistance increases in a circuit, it restricts the flow of current, causing a higher voltage drop across the resistor. This is Ohm's Law in action, which states that voltage (V) equals current (I) multiplied by resistance (R). Therefore, Technician A's statement is accurate. Technician B, on the other hand, is incorrect because high resistance actually decreases current flow, rather than increasing it.

The pressure cap is the correct answer because it is responsible for maintaining pressure in the cooling system. By increasing the pressure, the boiling point of the coolant is raised, allowing it to absorb more heat before boiling. This helps in preventing overheating of the engine and ensures efficient cooling. The pressure cap also acts as a safety valve, releasing excess pressure to prevent damage to the cooling system.

Technician A is correct. To measure amperage, the meter must be hooked up in series in a circuit. This means that the meter is placed in the path of the current flow, allowing it to measure the amount of current passing through. Technician B's statement is incorrect because placing the leads of the ammeter on the input and output sides of the load would not provide an accurate measurement of the amperage.

The correct answer is "they can be disassembled, cleaned, and repacked with grease." This is because flexible joints in the steering linkage are typically sealed and not intended to be disassembled or repacked with grease. They are designed to allow movement without looseness or play and are often equipped with a grease fitting for lubrication. The joints are usually of ball-and-socket design, which allows for flexibility and smooth movement.

Technician A is correct. Lug nuts should be torqued to specifications to ensure that they are tightened to the appropriate level. This helps to prevent over-tightening, which can lead to damage, or under-tightening, which can result in loose lug nuts and potential safety hazards. Following the recommended torque specifications ensures that the lug nuts are properly secured and maintains the integrity of the wheel assembly. Technician B is incorrect in suggesting that lug nuts should be tightened in a random sequence, as this can lead to uneven tightening and potential wheel imbalance.

Tech A is correct. A micrometer is a precision measuring instrument used to measure the thickness of objects with high accuracy. In the context of this question, a micrometer can be used to measure rotor thickness variation, which refers to the difference in thickness between different parts of the rotor. On the other hand, rotor lateral runout refers to the deviation of the rotor from its true circular path, and it is typically measured using a dial indicator or a runout gauge, not a micrometer. Therefore, Tech B is incorrect.

A fully charged battery is indicated by a voltage of 12.6 volts. This is because a fully charged lead-acid battery typically has a voltage of around 2.1 volts per cell, and since most automotive batteries have 6 cells, the total voltage would be 12.6 volts.

The master cylinder should be inspected for internal and external leaks in all of the given scenarios except when the brake pedal is harder to push than normal. This is because a harder brake pedal typically indicates a problem with the brake booster or the brake pedal linkage, rather than an issue with the master cylinder. In the other scenarios, such as low brake fluid, brake warning light on, or low brake pedal reserve height, there is a higher likelihood of a leak in the master cylinder, which requires inspection.

When measuring voltage with a voltmeter, the red lead should be placed in the "Volt/Ohms" slot and the black lead should be placed in the "Common" slot. This is because the "Volt/Ohms" slot is specifically designed to measure voltage, while the "Common" slot is used as a reference point for the measurement. Placing the leads in these specific slots ensures accurate voltage measurement.

Technician B is correct. A parasitic draw refers to an excessive amount of electrical current being drawn from the battery when the vehicle is turned off. This can drain the battery over time. When performing a parasitic draw test, it is important to wait until all of the modules in the vehicle have gone to sleep. Modules are electronic components in the vehicle that can draw power even when the vehicle is not in use. Waiting for them to go to sleep ensures an accurate test of the parasitic draw.

Both Tech A and Tech B are correct. Tech A is correct because if there is brake fluid under the dust boot of the wheel cylinder, it indicates a leak and the wheel cylinder should be replaced. Tech B is correct because if the return spring of a drum brake has failed on one wheel, it is likely that the springs on both rear wheels need to be replaced to ensure balanced braking performance.

The current flowing through a resistor in a series circuit is determined by Ohm's Law, which states that current (I) is equal to the voltage (V) divided by the resistance (R). In this case, the voltage is 12 volts and the resistance is 4 ohms. Therefore, the current flowing through the resistor can be calculated as 12 volts divided by 4 ohms, which equals 3 amps.

The correct answer is removing the front wheels to prepare for adjustment. This is because a pre-alignment inspection involves checking various aspects such as removing heavy items from the trunk or truck bed, inspecting and adjusting tire air pressure, and confirming correct tire size. However, removing the front wheels is not a part of the pre-alignment inspection process.

Technician B is correct. When checking a tire's air pressure, it is recommended to refer to the specifications on the tire placard, which is usually located on the driver's door, door pillar, or glove compartment lid. This information provides the manufacturer's recommended tire pressure for optimal performance and safety. The tire sidewall information may provide the maximum tire pressure, but it does not necessarily indicate the recommended pressure for normal driving conditions.

Tech B is correct. A service brake pedal that does not return causes the brake lights to stay on. This is because the brake light switch, which is activated by the movement of the brake pedal, may not be properly engaged if the pedal does not return to its original position. As a result, the brake lights will remain illuminated even when the brake pedal is not being pressed.

Camber refers to the inward or outward vertical tilt of the wheel. It is the angle at which the top of the wheel tilts towards the vehicle's center or away from it. This tilt helps distribute the weight of the vehicle evenly across the tire's contact patch, ensuring optimal traction and stability during cornering. Correct camber alignment is crucial for tire wear and overall vehicle handling.

When the piston moves from bottom dead center (BDC) to top dead center (TDC) or vice versa, it is referred to as a stroke. In an internal combustion engine, the piston undergoes four strokes in a cycle: intake, compression, power, and exhaust. During the intake stroke, the piston moves from TDC to BDC, drawing in the air-fuel mixture. In the compression stroke, the piston moves from BDC to TDC, compressing the mixture. The power stroke occurs when the ignited mixture pushes the piston from TDC to BDC, generating power. Finally, the exhaust stroke sees the piston move from BDC to TDC, expelling the exhaust gases.