Exam 4

Answer C is correct. Carbon buildup in the compressor discharge hose causes a longer -than-specified compressor air pressure buildup time.

14. And air brake system has slower than specified air pressure buildup time what could be the cause of the problem? A. A similar than specified supply reservoir B. An air leak in the compressor air intake filter C. Carbon buildup in the compressor discharge hose. D. And excess amount of water in the supply reservoir

Answer A is correct . A visual inspection would not reveal the proper belt tension. A belt tension gauge should be used whenever possible for the most accurate reading. If one is not available then the normal deflection points at the specified location and measurements should be observed.

15. Visual inspection of the following power steering belt can reveal all of the following except: A. Proper belt tension. B. Premature wear due to misalignment. C. Correct orientation of dual belt application. D. Proper belt seating in the Pulley.

Answer C is correct. Both technicians are correct A DDR can both read active codes and erase historic codes.

26. A digital diagnostic reader is connected to an American truck association connector During a routine PMI to read engine data. Technician A says active codes can be read. Technician B says the historic codes be a erased. Who is correct?

Answer A is correct. The Clarence light is shone and mounted on the Extreme right Or left side of the cab. Federal light regulations require all vehicles 80 inches or wider to have two Clarence lamps at the front and rear at the widest point and and high as paracticable.

27. What does the arrow in the illustration above indicate? A. Clarence light B. Identification light C. Fog light D. Intermediate light

Answer C is correct. Both technicians are correct. Truck equipped with power steering filter should have them changed, if required, as part of PMIs. When there has been a component show here, the power steering filter may be filled with it free from the filter, and should be changed.

28. While performing a routine maintenance, a technician observed that the power steering system has a filter. Technician A says the filter should be replaced, if required, on a preventative maintenance inspections according to the OEM. Technician B says the filter should be replaced after a component filter. Who is correct?

Answer D is correct. A broken engine mount will not cause the power steering pulley pulley to become misaligned

29. All of the following could cause the power steering pump pulley to become misaligned except: A. And overpassed pulley. B. Loose fit from pulley hub to pump shaft. C. A loose pump mounting bracket. D. A broken engine mount

Answer C is correct. Both technicians are correct. You can turn the key on the ignition to perform electronics system self check. Ignition switch powers up most computer controlled chassis systems.

3. Technician A says you can turn the key on the ignition to perform electronics system self check. Technician B says they ignition circuit powers most computer controlled Chassis systems. Who is correct?

Answer A is correct. Only technician is correct. The measurement should be between one and 2 inches with one and a half inch being typical. With the clutch pedal fully released there should always be 1/8 inch of free play between The release your fingers in the clutch release bearing pads. This free play is taken up by the first one to one and a half inches of pedal travel. Measure the distance the pedal can be pushed down before thrust is exerted on the clutch release bearing to check clutch pedal free travel.

1. A truck mechanically actuator clutch is being measured for free play. Technician A says the measurement should be between one and 2 inches. Technician B says that on hydraulic clutch FreePlay should be 2 to 3 inches. Who is correct?

Answer C is correct. Both technicians are correct. The vibration and dampers counterbalances the back-and-forth twisting motion of the crankshaft each time he still under fires. If the seal contact area on the vibration dampener of his score, the definition of family must be replaced.

10. Technician A says the vibration dampener Counterbalances the back-and-forth twisting motion of the crankshaft each time a cylinder fires. Technician B says if the seal contact area on the vibration damper hub scored, the damper assembly must be replaced. Who is correct?

Answer A is correct. Lateral run out and rotor thickness measurements are shown in the illustration to check lateral runout, mount a dial indicator on the steering arm and anchor plate with the indicator plunger contacting the rotor or 1 inch from the edge of the rotor. Checked lateral run out on both sides of the rotor. Zero the indicator and measure the total indicated runout. The lateral runout TIR is always a tight dimensions, seldom exceed 0.015 inch. If lateral run out exceeds the Specifications, the rotor will have to be either a machine or replace. Thickness variation should also be measured at 12 quadrants points with a micrometer at about 1 inch from the edge of the road her. If thickness Measurements vary by more than the specified maximum, usually around 0.002 inch, the rotor should be machine or replace.

11. What is being performed in this illustration above? A. Lateral run out and rotor thickness B. Wheel bearing run out C. Rotor thickness and radio right now D. Parallelism

Answer A is correct. A direct ground in the starter coils causes high current draw and no starter operation.

12. A starting motor fails to crank the engine and indicates a very high current draw. The most likely cause of the problem is: A. A direct ground in the starter field coils. B. An open circuit in the armature whining C. Broken brush Springs and no tension on the brushes. D. A failed magnet switch.

Answer C is correct. Both technicians are correct. The type of fire extinguisher carried on a truck should be determined by factors such as the type of cargo carried. Most fire extinguishers are marked by letter and symbol to indicate the class of fiers for which they extinguish bye. Every truck or truck tractor with a gross vehicle weight rating (GVRW) of 10,000 pounds or more must have a fire extinguisher. If the vehicle is use for transporting Hazardous material that requires placards, extinguisher must have an Underwriters laboratory rating of 10 BC or no more then. If the vehicle is not used for hazardous materials, and extinguisher with a UR rating of 5BC may be used. The rating is usually showing near the URL certification on the extinguisher . Section 396.19 of the Federal motor safety regulation states it is the fleet manager's responsibility to ensure that All personnel doing annual inspections are qualified to perform those inspection. They should understand the inspection criteria and be able to identify defective components and system.

13. A fleet manager is restricting a PMI program. Technician A says the fire extinguisher distribution varies with the type of vehicle it is installed in. Technician B says that it is the fleet manager's responsibility to see that personnel performing annual inspections are qualified. Who is correct?

Answer B is correct. Only technician B is correct. Listening to or reading the drivers report and then checking the truck's maintenance records for past problems or repairs before proceeding is the proper diagnostic sequence to follow. All through inspection of the door and associated components such as hinges and latches should be performed by determining a proper course of action.

16. A Driver complains of a door not closing properly and has brought it in for service. A Technician Immediately Greeces the hinges. Technician B retrieve the vehicle records and checks for past problems with the door and makes a note of the drivers report. Who is correct?

Answer C is correct. Both technicians are correct. Began battery service with a visual inspection looking for loose hold down, defective cables, damage terminal posts, loose terminal connections, clogged vents, corrosion, dirt or moisture, cracked case, and battery box condition. Follow a visual inspection, a battery open circuit voltage test can be used to determine its state of charge. A battery that has recently been charged by running the engine or using a battery charger must have its surface charge removed before performing the open circuit voltage test. A stabilized open circuit Reading 12.6 V or more indicate a fully charged battery.

17. Technician A always begins battery inspecting with a general visual first. Followed by an open circuit voltage test technician B says that it may be necessary to remove the service charge from the battery before it is open circuit voltage is tested. Who is correct

Answer A is correct. Only technician A is correct. Whenever any repair procedure or adjustment is performed on a vehicle, the work must be noted using a sign off sheet before the vehicle is put back into service. If the problem did not require repair, but Was still looked at, then This must be recorded as well a copy of the inspection report must remain in the vehicle.

18. A slack adjuster pushrod is being serviced on a vehicle following a drivers tagged on the post trip inspection. Technician A says that the service performed must be locked before the vehicle can be put back into service. Technician B says the service performed should be recorded on a P.M.I maintenance sheet. Who is correct?

Answer D is correct. The technician is checking the starter relay Operation. The starter relay is a remote mounted magnetic switch that uses low current to control high current flow from the battery to the starter motor. If the starter system has a magnetic switch, jumper around The heavy terminal to see if the motor cranks. If the starter motor cranks, the relay is defective, assuming the control current from the starting switch is available at a small terminal or relay.

19. What is being performed in the illustration above? A. Testing the battery out put B. Checking the continuity of the ignition switch C. Performing a voltage drop on the ground circuit side of the starter D. Bypassing the magnetic switch

Answer B is correct. In the cold. Is the temperature at which the normal paraffin a Feel becomes less salt water bowl and begins to precipitate as wax crystals and make the field the pier cloudy and hazy. The cloud. Exceeds the poor point by 5°F to 25°F.

2. Which of the following defines a cloud point of diesel fuel. A. The lowest temperature at which it will flow B. The temperature at which a haze of wax crystals will form C. The highest temperature before evaporation begins D. The temperature at which the fuel produces black smoke

Answer A is correct An open circuit voltage test maybe use in place of a Hydro meter test.

20. Technician A says an open circuit voltage test maybe use in place of a Hydro meter test technician B says during The open circuit voltage test the headlight should be on. Who is correct?

Answer D is correct. Cold temperature operation can cause transmission and axles lubrication problems known as channeling. High-viscosity oil's typically used in transmission and axles thicken causing greatly reduced flow, Or they may not slow at all when the vehicle is first started. Channeling leads to the components not getting proper lubrication. Rotating gears can push lubricant aside meaning voids or channels where notification is actually touching the gears.

21. In relation to lubricants transmission and drive axle what is channeling? A. Lubricant breaking down and high temperature B. Extreme pressures on components cause a lubricant to separate C. Liquid seeking the lowest center of gravity D. Components start of lubrication due to cold temperatures

Answer A is correct. Effective and/or Improper grounds Are the most common source of damn lights.

22. Technician A says that defective and or improper ground connections are the most common source of dim lights. Technician B says that when vehicle lighting inspections are performed, it is common practice to start at the back of the trailer and move forward. Who is correct?

Answer D is correct A restricted line will not cause a constant air leak from the dryer purge valve therefore, it is the exception.

23. All of the following would cause a constant leak from the air dryer purge valve except: A. Foreign particles on the valve seat. B. A purge valve seal damaged. C. A purge valve frozen. D. A restricted purge line.

Answer C is correct. Both technicians are correct. S-cam actuated foundation brake systems are the most common type of foundation brake system found on heavy-duty trucks. Slack adjusters working with S-cam converts the linear force developed by the brake chamber into brake torque.

24. Technician A says the S-cam actuator foundation brakes are the most common brakes system on heavy duty trucks today. Technician B says the slack adjuster and S-cam convert linear motion into brake torque. Who is correct?

Answer D is correct. A convex drum results when the diameter on the brake drum is greater at the edge of the friction surface then in the center.

25. The diameter on a brake drum is greater at the edges of the friction surface then in the center. This drum condition is: A. Bell mounted drum. B. Concave brake drum. C. Drum out of round. D. Convex brake drum

Answer C is correct. Both technicians are correct. Air and electric horns are important safety devices enabling the operator warn other motorists of danger. Any Whole arm wire functional. Any observed problem with a trailer front bumper, Fairing, or mounts Should be noted during a PMI.

30. Technician A said that air horns should be checked. During a PMI. Technician B says any physical damage founding to the front bumper of a trailer should be noted during a PMI is correct? A. A only B. B only C. Both A and B D. Neither A nor B

Answer B is correct. The engine should be checked for both static and dynamic weeks. This means that the engine should be checked while it is running and while it is off.

31. Technician A says that a minor cooling system leak is sufficient criteria for deadline. Technician B says that the engine should be checked for both static and dynamic leaks. Who is correct?

Answer A is correct. If you locate a fifth wheel too far forward on the tractor, hard steering and tire wear can result.

32. A fifth wheel is being mounted on a tractor. Technician A says that if it is it located too far forward, hard steering and tire wear can result. Technician B says the Fifth wheel should be mounted to the frame flanges by welding . Who is correct?

Answer D Is correct. Leakage at the break application valve exhaust port with the brakes are applied should not exceed a 1 inch bubble in 3 seconds

33. With the brakes applied at 80 psi and checking for maximum allowable leakage at the break application valve exhaust port all of the following are incorrect EXCEPT: A. A 2-inch bubble in 1 second. B. A 2-inch bubble in 2 seconds. C. A 3-inch bubble in 3 seconds. D. A 1-inch bubble in 3 seconds.

Answer A is correct. When the ABS check switch and the ignition switch our turn on, the ABS light flashes blinks codes.

34. When diagnosing an ABS with an ABS check switch and a light in the instrument panel, at all of the following are incorrect except: A. When the ABS check switch and the ignition switch are turned on, the ABS light flashes blinks codes. B. The first set of Flashers in the blink code sequence indicate whether the system is ABS only or ABS and automatic traction control. C. When there are no electrical defects in the ABS, a 0-0-0 blink code is revealed. D. A blink Code indicate whether in electrical defect is in a wheel speed sensor or the connecting wiring.

Answer D is correct. The battery condition should be checked first.

35. A customer has a truck towed in the shop and says the starter would not crank the engine over. What should be checked first? A. The ground cable connection B. The starter solenoid circuit C. The ignition switch crank circuit D. The battery condition

Answer C is correct. Both technicians are correct. And engine should be checked while doing an inspection for both static and dynamic leaks this means that the engine should be checked while it is running and while it is off this ensures that all gaskets and mating surfaces are Monitored in all possible operating and non-operating conditions. When checking for fuel leaks on an engine, it is mandatory that the engine be operating so the fuel system is pressurized, thus making a leak very apparent.

36. Technician A says that the engine can be checked for leaks while the engine is off. Technician B says to also check the engine for leaks while it is running. Who is correct?

Answer C is correct. Defective compressor gaskets will not cause brake system leakage.

37. All of the following could cause excess of leakage in the air brake system with the service brakes applied except: A. Leaking brake chamber diaphragm. B. Leaking hose, tube, or filling. C. Defective compressor gasket. D. A bad relay valve.

Answer C is correct. Both technicians are correct. The 1/2 inch measurement between the release bearing in the clutch brake provides the necessary pedal travel to produce release bearing to clutch brake contact at the four pedal position. The 1/8 inch release form to release bearing Clarence produce is the correct clutch pedal free play.

38. Technician A says a correctly adjusted Pull type clutch measurement 1/2 inch of clearance between the release bearing and the clutch brake disc. Technician B says a correctly adjusted Pull type clutch release fork needs 1/8 inch of clearance between itself and the release baring. Who is correct?

Answer C is correct. Light rust on the driveshaft surface will not affect driveshaft balance.

39. When inspecting driveshaft, all of the following can result in vibration except: A. Missing balance weight. B. Out of phase condition. C. Light rust on the driveshaft surface. D. Lose you joint cap.

Answer A is correct. Parallel connections are shown in the illustration above

4. What type of connection are pictured in the illustration above? A. Parallel B. Parallel-series C. Series D. Series-parallel

Answer A is correct. A battery drained of two Aampers would cause the battery to become discharge

40. Technician A says a battery drained of two Amperes Would cause the battery to become discharge. Technician B says the battery drain test should be performed with Engine at normal operating temperature. Who is correct?

Answer C. Is correct. If a steer axle tire has a tread depth of 5/32 inch At two adjacent trade grooves at any location on the tire, the tire is satisfactory. Minimum tread depth is 4/32 inch.

41. During an inspection, a tractor must be placed out of service if any of these tire conditions are present Except: A. If a tire is mounted or inflated so it contacts any part of the vehicle. B. If a drive axle tire has a tread depth of less than 1/32 inch at two adjacent tread grooves at three separate locations. C. If a steer axle tire has a tread depth of 5/32 inch Add two adjacent trade groups at any location on the tire. D. If the tire is labeled not for Highway use.

Answer B is correct. A VSS Is the most like because of improper cruise control set speed.

42. An electronic a cruise control maintains the vehicle speed at 45 mph when the selected speed is 60 mph. What is the most likely cause of this problem? A. A defective cruise control module. B. A defective vehicle speed sensor. C. Improper size of the tires on the drive axles. D. A defective cruise control switch.

Answer C is correct. Careless driving is the most likely cause of a circuit in the sidewall sidewall damage can lead To future tire failure

43. During a tire inspection, a technician notices a cut in the sidewall of the tire. Which of the following is most likely cause? A. Excessive toe-in B. Camber C. Careless driving D. Castor

Answer C is correct. Both technicians are correct. Vehicle ( straight trucks and semi-trailers) manufactured after 1998 are required to be equipped with the collapsible docking guards. The guard should be examined for damage during a PMI inspection since they are subjected to constant abuse. Check the guards and mounting hardware.

44. Technician A says that impact guards are required to be equipped on vehicles manufactured after 1998. Technician B says that the impact guards should be carefully inspected for damage during routine PMI inspection since they are subjected to abuse. Who is correct?

Answer A is correct. Only technician A is correct. A turbo charger should be checked for oil leaks when the engine is running without the engine producing oil pressure, it would be more difficult to detect leaks. The oil pressure to the turbo charger needs the bearings, spills to an oriole drain cavity, and certain drain to the crankcase by means of a return hose.

45. A turbo charger is being inspected for oil leaks. Technician A says to check it while the engine is running. Technician B measures turbine shaft radio round out with the engine running. Who is correct?

Answer A is correct. The bulkhead is a trailer body component.

46. All of the following are under side components of the trailer except: A. Bulkhead. B. Tires. C. Suspension. D. Landing gear.

Answer A is correct. Only technician A is correct. The engine/exhaust break should be tested on a road test. Use the engine break during the Road test when the engine RPM is in torque Rise. Note the disengage RPM.

47. And exhaust break is being inspected on a truck. Technician A says that this should be performed during the Road test. Technician B says that a properly functioning engine compressor break should be noiseless . Who is correct?

Answer D is correct. Neither technician is correct. It is important to know that all coolants are not alike and are not always compatible with each other. Identify the coolant being used and be sure to follow the printed change intervals and refill with the correct type. Extended life coolant have a longer service life and Etheline glycol and propylene glycol coolants. It is important to test the radiator cap to ensure that it will retain the indicated pressure setting. Using a pressure tester unit, install the cap onto a tester and apply pressure to the specified pressure release point. If the specified limit cannot be achieved, then Replacement is required. Pressure testing the engine cooling system for leaks is performed in the same manner. Apply pressure by means of the same test unit. They gauge reading shared achieve the same setting as a recommended radiator cap. The gauge reading should hold steady.

48. A cooling system on a heavy truck is being tested. Technician A says that the color of the coolant Indicates whether it is e.g., PG, or ELC. Technician B says to drain off a gallon of coolant before performing a pressure test who is correct?

Answer D is correct. The reefer a power supply is not part of the trailer lighting system.

49. Which of the following would be the least important part of the trailers lighting system to check? A. Side amber marker lights B. Interior overhead lights C. Main wiring input socket in associated wiring D. Reefer power supply

Answer A is correct. Only technician A is correct the service brakes are tested during road test of the vehicle. The brakes that are activated by the brake pedal are referred to as the service brakes. Work the breaks during the Road test using a mixture of snub Breaking and aggressive panic stops. The Federal motor vehicle safety standards sets (FMVSS) the standard use in the United States and Canada to define stopping distance as well as other breaking safety criteria.

5. When performing a test drive on a vehicle, technician A says to test the service breaks by applying and releasing them. Technician B says that although a test drive is not mandatory, it is a good idea to perform One after a vehicle has been serviced. Who is correct?

Answer D is correct. Neither technician is correct. Recommended intervals re-torquing is necessary. This is due to the constant flexing the stud/hub material. Overloading can be a factor. Manufacturers have specified intervals recommended for Wheel and rim inspections. Low profile tires decrease the load-carrying compacity of a vehicle. The low-profile tire Does offer several Advantages compared to conventional tires, which include reduced rolling resistance, cooler running, longer tread life, improved fuel economy, reduce the vehicle weight with a lower center of gravity, and improve traction.

50. Technician A says that re-torquing wheel lug nuts are not required when performing a PMI. Technician B says that increase load caring can Pacitti is an advantage of switching to low-profile tire. Who is correct?

Answer A is correct. A Pinched service brake airline, a stuck closed relay valve, or restricted tractor protection valve exhaust port will restrict the flow of air in the brake system. A leaking parking brake diaphragm will cause air to be heard leaking.

51. When the parking break is released on a tractor with air brakes , air is heard escaping at the rear axle of the tractor. Witch of these could be the cause? A. A leaking parking brake diaphragm. B. A pinched service brake air line. C. Stuck-close relay valve. D. A restricted tractor protection valve exhaust port.

Answer B is correct. Worn brake drum, a building automatic slack adjuster clevis pin, or low air brake system pressure will affect both brake shoes on a wheel and equally. Worn S-cam bushing will allow the S-cam to push more downward pressure, causing increased wear on the lower shoe.

52. During inspection of air brake shoes,The technician observe that on One of the wheel ends The lower Shoe lining worn Much thinner than the upper Lining. This could be caused by: A. A worn brake drum. B. Worn S-can-bushing. C. A binding automatic slack adjuster Clevis pin D. Low air brake system pressure.

Answer D is correct. Normal automatic slack adjuster stroke is approximately 2" And may vary slightly by manufacture. Push rod stroke should be checked with the air system at full operating pressure. Push rod stroke cannot be correctly measured with the brake chambers charged. No manual adjustments should be made to automatic slack adjuster's after initial installation and set up.

53. Which of these is a true statement about checking the adjustment and operation of automatic slack adjusters on a truck? A. The automatic slack adjuster is working correctly if the pushrod stroke is at least 4". B. The pushrod stroke should be checked with the air pressure at 60-65 P.S.I. C. The parking brake chamber should be charged before taking the pushrod measurements. D. Automatic slack adjusters should be manually adjusted during initial installation only.

Answer A is correct. A flashing "N" on the shifter indicator means that the transmission is not in NUTRAL gear range. Technician A's Statement is true. The normal voltage gauge reading indicates that the batteries are not discharged. Technician B's statement is false.

54. The starter will not crank the engine on a truck equipped with automatic mechanical transmission. With the ignition key in the on position, the voltage gauge shows normal and the shift indicator is flashing "N". Technician A says that the transmission being left in gear the last time the truck was parked could be the cause. Technician B says that the batteries being discharged could be the cause who is correct?

Answer D is correct. The burning of the lens is caused by overheating. High resistance in the ground circuit or the voltage feed circuit will cause the bulb to be dim, but not to overheat. Use of dielectric grease on the bulb socket can help reduce corrosion, but will not cause overheating. Use of the wrong bulb could cause an overheating condition.

55. When performing a lighting inspection, the technician observes the plastic lens of one of the lamps is burned. Which of these could be the cause? A. Hi resistance in the ground circuit. B. High resistance in the voltage feed circuit. C. Use of dielectric grease on the bulb socket. D. Use of the wrong bulb.

Answer B is correct. A shorted cell In a battery will result in low open circuit voltage reading during testing.

56. A truck has a slow cranking complaint. During open circuit voltage testing, one battery measures 10.5 v. This reading indicates that the battery: A. Has a surface charge. B. Has a shorted cell. C. Is overcharged. D. Is fully changed.

Answer A is correct. The condition of the fuel tanks, mountains, lines, and caps are a concern during a PMI. The fuel tank mounts should be securely attached to the frame and the tank and be free from any cracks, corrosion, and damage that could cause future failure. There should be no signs of tank shifting and all mounting bolts should be in the place and tight. Tanks must be checked for any signs of leakage at any point, with special attention to all seems and any damage areas. Checked to ensure that the Seal is in place and in good condition.

6. In addition to replacing the fuel filter and performing the fuel system what else should be performed when doing a preventative maintenance inspection on a fuel system? A. Check the fuel tank mountains. B. Test fuel pour point C. Check heater lines for Proximity to the fuel lines. D re-calibrate the fuel gauge.

Answer D is correct. Neither technician is correct. CVS out of service criteria shows that brake linings that are saturated with oil, Greece, or brake fluid and out of service condition.

7. And inspection is being performed on a heavy duty truck brake system and grease soaked linings are found on three wheels of the trailer rear tandem axle. Technician A says to inform the driver. Technician B writes of the problem and informs the driver. Who is correct?

Answer D is correct. Test the condition of the coolant first. Cool and freeze and boiling protection levels can be tested with a Hydrometer or a refactometer. Different anti-freeze in water ratio's are required to raise or lower the protection level depending upon the temperatures the vehicle will encounter. A 50/50 mixture is most common.

8. When winterizing a truck, which of the following procedure should be done first? A. Replacing lost coolant B. Cleaning the coolant C. Adding anti-freeze D. Passing the condition of the coolant

Answer B is correct. Through it is not desirable to mix tread designs, both tires are the same normal dimensions, so this is least likely

9. Which of these criteria is least likely to be considered tire miss matching? A. Radials and bias ply on the same axle B. Dual wheels of the same normal size but different tread design C. Installation of a new tire next to a worn out tires on the same axle D. Tires with different circumference on the same axle