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310 T PRACTICE EXAM 2 QUESTIONS AND CORRECT ANSWERS!!
Which of the following tools can be used to cut new external threads?! A die A thread pitch gauge A tap A thread chaser - ANSWER A die
During a PM inspection a broken radiator fan shroud is noticed. Which of the following could cause this damage?! Loose fan belts A failed fan hub clutch A broken engine mount An out of balance fan assembly - ANSWER A broken engine mount
During a PM inspection the steering wheel binds when turned. What could cause this condition?! Excessive sector gear to ball nut clearance in the steering gear Worn king pin bushings Worn steering shaft universal joints Worn tie rod ends - ANSWER Worn steering shaft universal joints
Although any loose or missing bolts should be tightened or replaced when noticed, what percentage of fifth wheel mounting bracket to frame fasteners can be loose or missing before the tractor must be placed out of service?! 10% 20% 30%
40% - ANSWER 20%
What type of tubing must be used in hydraulic brake systems?! Single wall thickness steel tubing Double wall thickness steel tubing Single wall thickness copper tubing Double wall thickness copper tubing - ANSWER Double wall thickness steel tubing
When cutting with an oxy-acetylene torch, what should you see in the steel before depressing the cutting lever?! A small liquid puddle A change in steel colour A change in steel colour to red A change in flame colour to red - ANSWER A small liquid puddle
What is the reading on this 2-3" imperial micrometer?! 2.341" 2.016" 2.516" 2.041" - ANSWER 2.341"
What tool should be used to measure the air filter restriction?! A water manometer A vacuum gauge A mercury manometer A pressure gauge - ANSWER A water manometer
When less load is applied to the truck When uneven terrain is encountered When the compressor begins its loaded cycle - ANSWER When more load is applied to the truck
What must be performed on a truck suspension system to adjust torque rod length and drive axle alignment?! Adjust the nuts on the U-bolts Add additional spring wedges Remove or add washers (shims) Adjust the position of the spring hangers - ANSWER Remove or add washers (shims)
What type of truck spring suspension system would be mounted above the main leaf spring assembly and only be utilized under heavy leads?! An air spring suspension A constant spring suspension An auxiliary spring suspension A coil spring suspension - ANSWER An auxiliary spring suspension
What component is used to control jounce and rebound and suppress truck suspension system oscillations?! An air spring A shock absorber A leaf spring A helper spring - ANSWER A shock absorber
When diagnosing a leaf spring suspension complaint of harsh ride which of the following could be the cause?! Seized front spring shackle pins
Tires under-inflated Broken leaf spring Inadequate fifth-wheel lubrication - ANSWER Seized front spring shackle pins
Which of the following is correct practice when mounting accessories to the heat-treated frame of a truck?! Never drill the web of the frame rail Never weld on the web of the frame rail Never drill or weld on the flange of the frame rail Never attach anything to the frame web - ANSWER Never drill or weld on the flange of the frame rail
What should be done first when the spring shackle pin will not accept grease?! Replace the sping pack Replace both zerk fittings Replace the spring pins Remove weight from the spring by using a jack - ANSWER Remove weight from the spring by using a jack
What condition could affect ride height when inspecting spring equalizers on a tandem axle air suspension system?! A leaking air spring A torque rod that is out of adjustment Worn equalizer bushings A tie rod that is out of adjustment - ANSWER Worn equalizer bushings
How is cushioning and alignment accomplished on a rubber cushion suspension system?! Drive pins are encased in rubber bushings
Hydraulic steering oil temperature is not important when testing - ANSWER The steering system oil should be at operating temperature
What is the recommended method of deflating a truck tire?! Use a screwdriver to depress and hold the Schrader valve pin Remove the Schrader valve core completely Separate the bead of the tire from the rim Fracture the valve stem, allowing all of the air to escape - ANSWER Remove the Schrader valve core completely
What could cause low-pressure readings when resting a hydraulic power steering system?! A worn hydraulic steering pump A relief valve is stuck closed A restricted steering valve A bent or damaged pitman arm - ANSWER A worn hydraulic steering pump
What could cause wheel tramp?! An overload condition An under-inflated tire A broken spring pack Static unbalance of a wheel assembly - ANSWER Static unbalance of a wheel assembly
Which of the following conditions on an air brake system could cause a high discharge of oil from the supply reservoir drain value?! Governor setting too high Governor setting too low A restricted lubricating oil return passage in the compressor Compressor drive belt slipping excessively - ANSWER A restricted lubricating oil
return passage in the compressor
While observing a truck's air-pressure gauges when building air pressure you notice the primary reservoir is fully charged but the secondary reservoir has zero air pressure. What could be the cause?! The secondary reservoir one-way check valve is stuck open The secondary reservoir one-way check valve is stuck closed The primary reservoir one-way check valve is stuck open The primary reservoir one-way check valve is stuck closed - ANSWER The secondary reservoir one-way check valve is stuck closed
What is the purpose of residual pressure in a hydraulic brake system?! To increase the speed of the brake application To inhibit moisture infiltrating the hydraulic fluid To increase applied brake pressure To decrease applied brake pressure - ANSWER To increase the speed of the brake application
A driver explains that his low air warning device (light) has activated, but the primary and secondary pressure gauges indicate full air pressure. What could be the cause?! A faulty governor setting An air leak at the supply reservoir A fault in the air dryer circuit The low-pressure warning circuit has malfunctioned - ANSWER The low-pressure warning circuit has malfunctioned
While troubleshooting an air pressure build up complaint you find no air pressure at the inlet side of the supply reservoir. What could be the cause?! A restricted air dryer Governor setting too high
The pup axle The lead trailer axle - ANSWER The pup axle
Which of the following would be an output of the ECU (electronic control unit) of an air brake ABS (anti-lock brake system)?! The ABS indicator dash light The exciter ring The brake treadle valve The speed sensor - ANSWER The ABS indicator dash light
Brake wear is uneven on only one side of the shoes. What should be checked?! Anchor pins and bushings Improper sized shoes Worn S-cam bushings ABS sensor out of adjustment - ANSWER Anchor pins and bushings
What is the desired air gap between the ABS wheel speed sensor and the exciter ring?! 1/4" (6.25mm) 3/8" (9.5mm) Air gap is not critical As close as possible - ANSWER As close as possible
What is the proper position of hole(s) on air spring brake chambers?! At a 90° angle At a 30° angle Facing downwards, toward the road On the top, where it can be accessed - ANSWER Facing downwards, toward the road
What is the purpose of residual pressure in a hydraulic brake system To increase speed of a brake application To inhibit moisture infiltrating the hydraulic system To increase applied brake pressure To decrease applied brake pressure - ANSWER To inhibit moisture infiltrating the hydraulic system
Air pressure is higher than normal. What is the most likely problem?! Un-loader valve is stuck open Defective governor circuit Signal from supply tank Air compressor is over capacity - ANSWER Defective governor circuit
What is an important requirement when selecting replacement S-cams?! Identify if a left or right hand S-cam is required None, as all S-cams are identical Check for S-cam roller lubrication Test Rockwell hardness - ANSWER Identify if a left or right hand S-cam is required
What results when the dash-mounted trailer air supply valve (red) is pulled outward (closed)?! Air is directed through the tractor protection valve The trailer air supply line is fully charged The tractor parking brakes are applied The trailer parking brakes are applied - ANSWER The trailer parking brakes are applied
25-120 psi in 5 minutes or less 75-100 psi in 25 seconds or less 85-100 psi in 4 minutes or less 85-100 psi in 2 minutes or less - ANSWER 85-100 psi in 2 minutes or less
A 12-V lead-acid battery with an electrolyte temperature of 20°is voltage tested out of chassis and produces a voltage reading of 12.4 V across its terminals. Which of the following is more likely to be true?! Battery is fully discharged Battery is 50% charged Battery is nearly fully charged Battery should be replaced - ANSWER Battery is 50% charged
What voltage value should be indicated as the input terminal of a 2-wire, coolant temperature sensor in a typical truck diesel engine?! Zero V Up to 2.5 V-DC Close to 5 V-DC Between 12.6 and 14.1 V-DC - ANSWER Close to 5 V-DC
What type of output would you measure from a throttle position sensor described as "non-contact"?! WM (pulse width modulation). DC analogue AC analogue 3-phase ripple - ANSWER WM (pulse width modulation)
When you are testing a diode and it conducts equally well both ways, which of the following is probably true about the state of the diode?!
Forward bias Reverse bias Open Shorted - ANSWER Shorted
When preparing to boost a set of discharged batteries on a truck chassis, where should you locate the ground clamp on the truck you are boosting?! Anywhere on the frame Alternator ground clamp Directly to a battery negative post Directly to a battery positive post - ANSWER Directly to a battery negative post
A driver complains his radio produces constant static and his newly replaced batteries are often too discharged to crank the engine. After ensuring that the batteries are fully charged, which of the following should you check first?! Alternator AC leakage Alternator amperage output Cranking motor ground integrity Battery warranty - ANSWER Alternator AC leakage
You are measuring resistance through an NTC (negative temporary coefficient) thermistor-type temperature sensor and a reading of 75 kilo-ohms is displayed on a DMM (digital micrometer). What should be done?! Discard the sensor, resistance should be close to zero Heat the thermistor using a torch to see if resistance goes up Cool the thermistor using dry ice to see if resistance goes down Nothing. Most good thermistors test between 50 and 100 kilo-ohms resistance - ANSWER Nothing. Most good thermistors test between 50 and 100 kilo-ohms resistance
Create a temporary short at the starter solenoid - ANSWER Use a carbon pile
When load-testing a fully charged lead-acid battery at 20°C, which of the following would be the recommended load to be drawn by the carbon pile?! 1/2 of the CCA rating for 15 seconds 100% of the CCA rating for 30 seconds 1/2 of the amp/hour rating for 45 seconds 1/2 of the amp/hour rating for 15 seconds - ANSWER 1/2 of the CCA rating for 15 seconds
When preparing to lead-test a maintenance-free, lead-acid battery, the technician first checks the integral hydrometer eye and sees that it is clear. What should be done next?! Fully charge the battery before attempting to test it Replace the battery, it has a low electrolyte level Proceed with the test, the battery is fully charged Remove the surface charge, then proceed to test the battery - ANSWER Replace the battery, it has a low electrolyte level
What is the primary function of a gel-cell battery in a truck chassis battery bank?! Boosts available cranking power Powers 24V side of 12/24 system Auxiliary power source when engine is not running Stabilizes alternator output - ANSWER Auxiliary power source when engine is not running
If you suspect that a lead-acid battery has frozen, what should you do first?! Replace the battery Charge at high amperage Heat with a propane torch
Trickle charge and observe response - ANSWER Trickle charge and observe response
which of the following methods should be observed to crank a hard-to-start, truck diesel engine?! Crank for 2 minutes, rest for 15 seconds Crank for 30 seconds, rest for 2 minutes Crank for 15 seconds, rest for 2 minutes Crank until the batteries die - ANSWER Crank for 30 seconds, rest for 2 minutes
When an alternator is full-fielded, which of the following temporarily ceases to function?! Rectifier Rotor magnetic field Voltage regulator Stator - ANSWER Voltage regulator
How are the stator windings in a typical truck alternator configured?! Wye connection Delta connection Twisted triad Semi-elliptical - ANSWER Delta connection
What specific charging system component is evaluated when you perform an AC leakage test?! Stator Field windings Diode bridge Voltage regulator - ANSWER Diode bridge
from each wire before crimping?! 2mm 6mm 10mm 15mm - ANSWER 6mm
When adjusting truck body panels, how should a door be aligned to the front fender?! Slightly inboard from the fender Slightly outward from the fender Slightly higher than the fender Slightly lower than the fender - ANSWER Slightly inboard from the fender
In the 7-way tractor trailer electrical cord, what wire colour is designated for the stop lights?! Blue Brown Red Yellow - ANSWER Red
On the rear of a van trailer, where should reflective (conspicuity) tape be placed?! Across the full width of the trailer base Outlining the upper corners Outlining the lower corners Up the full length of the van sides - ANSWER Outlining the upper corners
When performing trailer refrigeration services, what refrigerant would most likely be used?! R-
R-
R-
R-502 - ANSWER R-
When performing repairs or service work on refrigeration components, what safety equipment should a technician wear?! Leather gloves and safety goggles Non-absorbent gloves and safety goggles Face shield and a metallic apron Safety equipment is not required - ANSWER Non-absorbent gloves and safety goggles
If a coolant control valve of a HVAC unit did not close completely, what would be the result?! The AC unit would cool more than required by the temperature switch The HVAC unit would not be able to regulate the air outlet temperature The HVAC unit would not be able to control the level of air flow in the cab The AC unit would not be able to provide maximum cooling - ANSWER The AC unit would not be able to provide maximum cooling
What is the most likely cause of a driver complaint that the cab AC works well when first turned on, but then intermittently after extended operation?! The expansion valve is stuck in the closed position The expansion valve is stuck in the open position There is moisture present in the AC system The discharge line from the compressor is restricted - ANSWER There is moisture present in the AC system
What would you suspect to be the problem if, while troubleshooting a truck's AC system you find gauge readings that are normal and line temperatures that feel correct, however vent air discharge is not cool enough?!
