Download 1. The mechanical action which results in fuel mixture being drawn

1.
The mechanical action which results in fuel mixture being drawn into the cylinder of a four
cycle engine is the:
a.
b.
c.
d.
2.
Of the following conditions, the one which is the likely cause of excessive engine
temperature is:
a.
b.
c.
d.
3.
air from the intake manifold
electricity from the battery
engine vacuum
vacuum from the fuel pump
The device that is actuated by pressure in the brake line and expands to force the shoes
against the drum in braking action is a:
a.
b.
c.
d.
5.
engine fan belt is too tight
ignition timing is too late or too early
a dirty air cleaner
engine thermostat is opening too wide
The source of power used to assist braking in power brake units on automobiles is:
a.
b.
c.
d.
4.
opening of the butterfly valve
closing of the breaker points
downward motion of the pistons
rotation of the distributor rotor
wheel cylinder
master cylinder
self adjusting screw
return spring
In the hydraulic brake system, “master cylinder” is:
a.
b.
c.
d.
the name applied to the double piston wheel cylinder
the device for distributing the pressure evenly to each of the two brake shoes
the means of adjusting the brake shoes to the proper drum clearance
the cylinder in which hydraulic pressure is built up for moving the wheel cylinder
pistons
1
6.
Of the following defects in a brake system, the one which is most likely to cause the brakes
on ALL FOUR WHEELS to drag is:
a.
b.
c.
d.
7.
Of the following, the most likely cause of a pulsating brake pedal when braking is:
a.
b.
c.
d.
8.
pressure
friction
centrifugal force
vacuum
The instrument used to measure lateral runout on disc brakes is:
a.
b.
c.
d.
11.
improper brake shoe clearance
a leak in the hydraulic system
worn brake linings
air in the hydraulic system
The physical concept which gives rise to the stopping ability of all braking systems is:
a.
b.
c.
d.
10.
an eccentric drum
a leaking hose
high fluid or air pressure
low fluid or air pressure
Under pressure, the brake pedal of a car equipped with hydraulic brakes goes gradually to
the floorboard. The “feel” of the pedal is firm. The most likely trouble is:
a.
b.
c.
d.
9.
the drums or discs are worn too thin
a faulty master cylinder check valve
there is air in the hydraulic brake fluid
the air pressure is too low in all four tires
a vernier
a caliper
an inside micrometer
a dial indicator
Of the following conditions, the one which is NOT a cause of pedal pulsation in disc brakes
is:
a.
b.
c.
d.
thickness variation
rotor runout
scored rotors
loose wheel bearings
2
12.
The type of valve in an air brake system which permits the operator to control the pressure
in the brake chamber when applying the brakes is a:
a.
b.
c.
d.
13.
The proper procedure for testing the governor on an air brake system for proper operation is
to check the:
a.
b.
c.
d.
14.
on the compressor
on the air brake system
on the air tank reservoir
near the pressure gauge in the cab
The parking brakes fail to apply on a truck with air brakes. Technician A says that low air
pressure in the spring brake chamber could be the cause. Technician B says that a ruptured
spring brake diaphragm could be the cause. Who is right?
a.
b.
c.
d.
16.
water pressure on the pressure gauge
cut-in and cut-out pressure
brake spindle pressure meter
main pressure relief valve
The most likely location of the governor in an air brake system is:
a.
b.
c.
d.
15.
relay emergency valve
quick release valve
safety valve
treadle valve
A only
B only
Both A and B
Neither A nor B
A technician should do which of these before taking apart a spring type parking brake?
a.
b.
c.
d.
remove the quick release valve
remove the diaphragm clamp
cage the spring
fill the air reservoir
3
17.
The service brakes in a truck with an air brake system release too slowly. Technician A
says that low air pressure could be the cause. Technician B says that a partly blocked
tubing or hose could be the cause. Who is right?
a.
b.
c.
d.
18.
The air pressure drops too fast when the brakes are applied fully. Any of these could be the
cause EXCEPT:
a.
b.
c.
d.
19.
a worn treadle (foot control) valve exhaust seat
a leaking brake chamber
a stuck shut quick release valve
a bad tractor protection valve
The driver of a truck with air brakes says it has poor stopping power. Any of these could be
the cause EXCEPT:
a.
b.
c.
d.
20.
A only
B only
Both A and B
Neither A nor B
the quick release valve exhaust port is plugged
the air pressure is too low
the application line is restricted
the brakes are adjusted wrong
A leaking service brake chamber diaphragm can be detected by a hissing noise when:
a. brakes are held applied
b. brakes are released
c. neither of the above
21.
When water is found on the pressure side of the brake chamber diaphragm, it usually
means:
a.
b.
c.
d.
22.
a cracked brake chamber housing
failure to drain air tanks
worn piston rings in the air compressor
a leaking air connection
On a tandem axle trailer, one brake is getting less air than others. This indicated:
a. a defective relay-emergency valve
b. a defective quick release valve
c. a clogged or restricted air line
4
23.
In an “S” cam brake, the brake chamber push-rod is returned to its released position:
a. by action of the brake shoe retracting springs
b. by brake shoe ends pressing against the cam
c. by action of the spring in the brake chamber
24.
A relay valve is used in an air brake system to:
a.
b.
c.
d.
25.
speed air delivery to brake chambers on remote axles
speed air release from chambers on remote axles
increase air pressure to rear axle or trailer brakes
a and b
A broken brake chamber diaphragm return spring can result in:
a. failure of brakes to release
b. failure of brakes to apply
26.
If two different diameter tires are used on the steerable axle of a vehicle, there will be a
tendency to pull during a brake application:
a. in the direction of the smaller tire
b. in the direction of the larger tire
27.
To a mechanic, the term “electrolyte” means:
a.
b.
c.
d.
28.
a device for automatically switching lights on and off
the solution of acid and water in which battery plates are immersed
a panel upon which the various fuses connected to the wiring on a car are arranged
a testing device for determining the candle power, direction and focus of light beams
The function of the cranking motor (starter) is to:
a. supply the ignition to the fuel mixture in the cylinder
b. rotate the alternator in order to supply the engine with power until the engine starts to
operate by internal combustion
c. regulate the amount of current to properly operate the engine
d. rotate the crankshaft by means of the flywheel
29.
The instrument that is used for measuring electrical resistance is the:
a.
b.
c.
d.
voltmeter
ohmmeter
micrometer
wattmeter
5
30.
One of the functions of the alternator is to:
a.
b.
c.
d.
31.
The part of the alternator which functions as a “magnetic field” is:
a.
b.
c.
d.
32.
transmission
starting motor
camshaft
rear axle
The unit of quantity of electricity flowing per second is:
a.
b.
c.
d.
35.
12-volt test light
ohmmeter
ammeter
voltmeter
The part to which the Bendix drive pinion is connected is the:
a.
b.
c.
d.
34.
stator
diode
rotor
pulley
The instrument used to measure electrical pressure or potential in a circuit is the:
a.
b.
c.
d.
33.
put a hot spark at spark plugs when needed
by-pass the battery
restore electrical energy to the battery
protect the battery from overcharging
ampere
ohm
volt
watt
The specific gravity of electrolyte in a fully charged lead-acid storage battery should be
approximately:
a.
b.
c.
d.
1.000 – 1.100
1.140 – 1.230
1.100 – 1.140
1.260 – 1.280
6
36.
Of the following, the appropriate instrument to use to test a diode of a 12-volt alternator is
the:
a.
b.
c.
d.
37.
The change that will result if the resistance in a series circuit is gradually increased is:
a.
b.
c.
d.
38.
too high a charging rate
too low a charging rate
high starter draw
too much acid in the battery solution
The factor for which the specific gravity rating of electrolyte in a battery must be corrected
is:
a.
b.
c.
d.
41.
the frequency of an alternating current
high voltages to low voltages
alternating current to direct current
direct current to alternating current
The probable cause of a battery continually using a large amount of water is:
a.
b.
c.
d.
40.
voltage across the power supply will decrease
current in the circuit will decrease
voltage across the power supply will increase
current in the circuit will increase
The function of a rectifier is to change:
a.
b.
c.
d.
39.
ohmmeter
stroboscope
growler
110-volt test lamp
amount of charge in the battery
atmospheric pressure
temperature
the number of cells in the battery
The electrical condition of the rotor windings that is indicated when the leads of a test light
are connected to both slip rings of the alternator and the lamp fails to light is:
a.
b.
c.
d.
normal
ground
short
open
7
42.
The type of connection which should be used to measure the voltage and current supplied to
an automotive cranking motor is:
a.
b.
c.
d.
43.
The usual voltage regulator setting on a 12-volt system is:
a.
b.
c.
d.
44.
hydrostatic
hydraulic
electromagnetic
electrical
The term for the play between gears is:
a.
b.
c.
d.
47.
worn starter bushings
grounded armature
defective field coils (grounded)
defective starter relay
The type of pressure used to operate automatic transmission clutches, servos and bands is:
a.
b.
c.
d.
46.
8v – 10v
10.2v – 13v
13.8v – 14.2v
14.5v – 18v
All of the following could cause high starter current draw EXCEPT:
a.
b.
c.
d.
45.
voltmeter and ammeter in parallel to the line
ammeter parallel to the cranking system and voltmeter in series with the motor
voltmeter and ammeter in series with the motor
voltmeter parallel to the cranking system and ammeter in series with the cranking motor
eccentric
backlash
thrust
lapping
The proper set of conditions for checking automatic transmission fluid level is:
a.
b.
c.
d.
with the engine cold and NOT running
with the engine warm but NOT running
with the engine cold and running
with the engine warm and running
8
48.
The clutch part that is between the pressure plate and the engine flywheel is called the:
a.
b.
c.
d.
49.
The valve that makes a transmission sensitive to road speed is the:
a.
b.
c.
d.
50.
faulty bands or multiple disc clutch
pressure regulator valve
rear pump seal
accumulator valve
The component which controls the timing of gear shifts in an automatic transmission is the:
a.
b.
c.
d.
53.
high
low
second
reverse
The most likely cause of an automatic transmission chattering is the:
a.
b.
c.
d.
52.
transition valve
inhibiter valve
governor valve
sensitivity valve
The gear range in a manual synchromesh transmission for which a synchronizing
mechanism usually is NOT provided is:
a.
b.
c.
d.
51.
throwout bearing
friction disc
clutch fork
clutch pedal
output shaft
governor
neutral start switch
output flange
The mechanism which makes it possible for one rear wheel to turn faster than the other
when a rear wheel drive vehicle corners is the:
a.
b.
c.
d.
worm gear
floating axle
universal joint
differential
9
54.
The mechanism that connects the transmission to the propeller shaft is the:
a.
b.
c.
d.
55.
The location at which a hydraulic assisted clutch can be checked more accurately for
clearance is at the:
a.
b.
c.
d.
56.
the transmission input shaft
the sun gear shaft
a hub on the back of the torque converter
the transmission output shaft
The three functional parts of a torque converter are the:
a.
b.
c.
d.
59.
total gear reduction
rear axle ratio
torque ratio
transmission-gear ratio
The device that drives the automatic transmission front pump is:
a.
b.
c.
d.
58.
clutch pedal
slave cylinder
throw-out bearing
pilot bearing
The term for the number of times the engine crankshaft turns over to one revolution of the
rear wheels is:
a.
b.
c.
d.
57.
level gear
connecting rod
differential
universal joint
impeller, turbine and stator
turbine, stator and valve body
impeller, stator and valve body
turbine, impeller and valve body
The instrument used to check backlash in a differential is:
a.
b.
c.
d.
a feeler gauge
a go-no-go gauge
a dial indicator
calipers
10
60.
The type of gearing used in most overdrive units is:
a.
b.
c.
d.
61.
The two general types of power steering are:
a.
b.
c.
d.
62.
tracking
rebound reaction
vehicle sag
road wandering
The type of axle assembly from which the axle shafts can be withdrawn without removing
the wheels is the:
a.
b.
c.
d.
65.
steering radius
caster
toe-in
camber
The purpose of the shock absorbers is to control:
a.
b.
c.
d.
64.
integral and manual
manual and rotary
rotary and power-assist
power-assist and integral
The term for the inward and outward tilt of the wheel at the top is:
a.
b.
c.
d.
63.
differential
planetary
hypoid
gear and pinion
plain
semi-floating
three-quarter
full-floating
The operation necessary to vary toe-in is to adjust the:
a.
b.
c.
d.
length of the tie rod
ratio of caster to camber
wheel bearing tightness
king-pin sidewide inclination
11
66.
The condition which is most likely to cause an engine to run sluggishly, overheat and throw
out black smoke is:
a.
b.
c.
d.
67.
The two types of fuel systems most common in diesel engines are:
a.
b.
c.
d.
68.
using the heat generated from the compression of air in the cylinder
using a spark generated by an electrical coil in the system
the fusion of fuel with catalytic agents
a localized heat-increasing reaction between an oxidant and fuel
The problem likely to result from an obstruction restricting the air passages of the air
cleaner is:
a.
b.
c.
d.
71.
anti-knock properties
density
freedom from impurities
specific gravity
Ignition is accomplished in the diesel engine by:
a.
b.
c.
d.
70.
high-pressure and pressure-time
high-pressure and unit injection
unit injection and pressure-time
unit injection and level action
The octane rating of gasoline has reference to its:
a.
b.
c.
d.
69.
water in a fuel
too lean a mixture of fuel and air
too rich a mixture of fuel and air
air bubbles in the fuel line
too rich a fuel mixture
a vacuum in the fuel line
vapor lock
too lean a fuel mixture
Of the following, the most probable cause of a slipping clutch is:
a.
b.
c.
d.
weak or broken clutch pressure springs
too much clutch pedal free travel
a worn clutch pilot bearing
a cracked or broken clutch pressure plate
12
72.
The most probable cause of the tires on the front wheels on a vehicle wearing evenly but
diagonally to the tread, is that the:
a.
b.
c.
d.
73.
Of the following, the best method of isolating a knock caused by a worn rod bearing is to:
a.
b.
c.
d.
74.
put a load on the engine
use a sound bar
short the injector
idle the engine at high speed
If the lights become dim when the engine is stopped, the most likely cause is:
a.
b.
c.
d.
75.
wheels are out of alignment
front brakes need adjusting
front wheels are larger than the back
front shock absorbers need replacement
an overcharged battery
a low or discharged battery
a short in the electrical system
a broken battery ground wire
Of the following, the most likely result of a loose pitman arm is:
a.
b.
c.
d.
difficult shifting
a noisy engine
excessive steering free play
a noisy differential
76. Of the following, the MOST PROBABLE cause of black smoke, indicating rich mixture,
issuing from all cylinders of a diesel engine, is that the:
a.
b.
c.
d.
77.
air cleaner is plugged or dirty
injector is plugged
injector valve needle is sticking
fuel filter is plugged or dirty
If the engine cranks slowly but will not start on a warm day in a car with a new battery, the
trouble is probably due to a:
a.
b.
c.
d.
open solenoid circuit
defective alternator
improperly adjusted regulator
defective starter
13
78. The condition that will result from improper backlash adjustment in a differential is:
a.
b.
c.
d.
improper ring and pinion mesh
excessive spider gear clearance
improper axle shaft end-play
a growl or whining noise from the wheel bearings
79. The vacuum gauge reading for a normal 8-cylinder engine running at a fast idle should be
approximately:
a.
b.
c.
d.
4 – 6 inches
6 – 10 inches
12 – 16 inches
18 – 22 inches
80. The defective part which would be indicated by a severe vibration at road speeds is the:
a.
b.
c.
d.
gear shift lever
universal joint
spider gear operation
axle bearing
81. An indication that a diesel engine is not burning the fuel properly is:
a.
b.
c.
d.
stopping of the engine
knock
irregular firing
smoke puffs
82. In the diesel engine cycle, which one of the following events occurs FIRST in the series of
events?
a.
b.
c.
d.
e.
fuel injection
air intake
expansion of gases
air compression
fuel ignition
83. In the diesel engine cycle, which one of the following events occurs THIRD in the series of
events?
a.
b.
c.
d.
e.
fuel injection
air intake
expansion of gases
fuel ignition
air compression
14
84. How can a mechanic tell whether all the cylinders in a diesel engine are getting fuel and are
firing?
a.
b.
c.
d.
by the temperature reading of the exhaust
by listening to hear differences in sound of the various cylinders
by feeling the water jackets around the cylinder
all of the above
85. Engine parts of a diesel engine may be broken down into four main groups. A “control
device” part would likely be included in which one of the following main groups?
a.
b.
c.
d.
structural parts (non-moving)
major moving parts
parts for getting air in and exhaust gases out
parts of the fuel injection system
86. A “piston” part would be included in which one of the four following main parts’ group?
a.
b.
c.
d.
structural parts (non-moving)
major moving parts
parts for getting air in and exhaust gases out
parts of the fuel injection system
87. There are four strokes in the working cycle of the majority of high-speed diesel engines.
Which one of the following is the SECOND stroke in the cycle?
a.
b.
c.
d.
compression stroke
exhaust stroke
power stroke
inlet stroke
88. Which one of the following actions of a four-cycle diesel engine follows the injection of fuel
into the cylinder?
a.
b.
c.
d.
intake stroke
compression stroke
power stroke
exhaust stroke
89. What kind of a lubricating system is generally used in a diesel engine?
a.
b.
c.
d.
force feed
back pressure
centrifugal force
splash feed
15
90. Which one of the following diesel parts has the effect of reducing the speed fluctuations of
the crankshaft by storing energy or giving it back?
a.
b.
c.
d.
flywheel
balancer shaft
bearings
wristpin
91. The camshaft and drive, push rods and rocker arms are part of which assembly in a diesel
engine?
a.
b.
c.
d.
fuel injection
scavenging system
combustion system
valve mechanism
92. A diesel engine develops too much boost at high engine rpm. Technician A says the oil bath
air filter is dry. Technician B says the wastegate is malfunctioning. Who is right?
a.
b.
c.
d.
A only
B only
Both A and B
Neither A nor B
93. Excess exhaust back pressure may result in all of the following EXCEPT:
a.
b.
c.
d.
lower engine power
higher exhaust temperature
higher intake vacuum
poor combustion
94. When using a voltmeter to perform a voltage drop test in a circuit the leads should
connected in what way?
A.
B.
C.
D.
to the battery terminals
from the positive battery terminal to ground
in series with the circuit being tested
in parallel with the circuit being tested
16
be
95. Technician A says to always start the good vehicle before making connections so the battery
will have enough cranking power. Technician B says to make the connections first so a
short will not blow the good vehicle’s charting system. Who is right?
A.
B.
C.
D.
96.
A only
B only
Both A and B
Neither A nor B
Low engine power is a result of insufficient fuel delivery to a unit injector. Which of the
following would be the LEAST likely cause?
A.
B.
C.
D.
97.
Technician A says that the battery term ampere hour refers to stored charge capacity of a
battery. Technician B says that a 75-ampere hour charge applied to a 200-ampere hour
battery should turn the charge indicator green. Who is right?
A.
B.
C.
D.
98.
A only
B only
Both A and B
Neither A nor B
When the throttle is moved from wide open to closed the throttle position sensor should
indicate:
A.
B.
C.
D.
99.
Suction leaks in fuel supply system
Incorrect throttle travel
Clogged fuel filter
A leak in the injector return line
0 VDC to 5 VDC
5 VDC to 0 VDC
5 VDC to continuous
0 VDC to continuous
Technician A says in a PT injector system when that pressure of fuel against the angular
surface of the injector needle exceeds the spring tension, the injector fires. Technician B
says in a unit injector system when the cam lobe presses the plunger of the injector down,
it pressurizes fuel and injects fuel into the cylinder. Who is right?
A.
B.
C.
D.
A only
B only
Both A and B
Neither A nor B
17
100.
What is the meaning of the abbreviation “DTC” as it pertains to the error codes on the
modern diesel engine?
A.
B.
C.
D.
101.
Technician A says that when performing a starter load test you should not crank the
engine for more than 30 seconds at a time. Technician B says you can perform this test
with a battery charger connected to the battery. Who is right?
A.
B.
C.
D.
102.
blower
inlet side of the turbo charger
intake manifold
exhaust manifold
Technician A says that the throttle position sensor is connected to a 5-volt reference.
Technician B says when the throttle is manually opened, the scan tool should read a low
voltage. Who is right?
A.
B.
C.
D.
104.
A only
B only
Both A and B
Neither A nor B
Which of the following is LEAST likely to have the air shut down valve mounted to it?
A.
B.
C.
D.
103.
drive train codes
diagnostic trouble codes
direct trouble codes
direct transmission codes
A only
B only
Both A and B
Neither A nor B
Technician A says the ECM connectors should never be probed through the weather pack
seals. Technician B says a test kit should be used to test connectors. Who is right?
A.
B.
C.
D.
A only
B only
Both A and B
Neither A nor B
18
105.
While rebuilding a differential that has 200,000 miles of service on it, a technician
notices faint, equally spaced grooves on the bearing caps. Technician A says the bearing
caps are showing signs of a spun bearing and must be replaced. Technician B says the
marks are from the original machining process and do not need to be replaced. Who is
right?
A.
B.
C.
D.
106.
The following are all checks that should be made to axle shafts to determine whether or
not replacement is necessary EXCEPT:
A.
B.
C.
D.
107.
bending of the axle shaft
twisting of the axle shaft
scored or pitted bearing race surfaces
pitting or chipping of the axle shaft splines
Technician A says that a broken wheel speed sensor wire can be fixed with a crimp splice
or equivalent. Technician B says that you must replace the entire wheel speed sensor to
fix the vehicle. Who is right?
A.
B.
C.
D.
108.
A only
B only
Both A and B
Neither A nor B
A only
B only
Both A and B
Neither A nor B
What is a rule that applies equally to almost all air systems?
A. the first sign of moisture in the line indicates that repair is needed
B. air operated equipment depends on air pressure in only one direction;
movement
in the opposite direction requires mechanical means
C. because air systems are closed they need no filters
D. air lines cannot have more than three 90-degree bends per 5-foot section
109.
All of the following could correct axle alignment EXCEPT:
a.
b.
c.
d.
radius rod
axle shaft
track bar
adjustment eccentric
19
110.
The two types of equalizing (walking) beam suspensions are:
A.
B.
C.
D.
111.
The physical size of a resistor is an indication of its:
A.
B.
C.
D.
112.
ampere
coulomb
valence
volt
A device which uses electromagnetic induction to convert electrical energy to mechanical
energy is called
A.
B.
C.
D.
115.
piezoelectric action
thermocouple action
chemical action
photoelectric action
The unit of measure for current is the
A.
B.
C.
D.
114.
type construction
power handling capability
tolerance
resistance
Electrical energy in a battery is created by
A.
B.
C.
D.
113.
air spring and spring
leaf spring type and rubber load cushion type
torsion bar and load leveling
progressive and auxiliary spring
an alternator
a motor
a magnet
an electromagnet
Which component of a unit injector system is LEAST likely to be the cause of an
improper injector spray pattern?
A.
B.
C.
D.
plugged nozzle tip holes
a stuck injection nozzle
improper timing of injectors
excess injector-to-follower clearance
20
HEAVY EQUIPMENT MECHANIC WELDING TEST
Candidate:
XXXXX
Date: ________
Plate Number:
XX
T-Joint Flat – 1 – Pass 10 Gauge, Hard Wire
Possible Points
Score
Comments
Shape and Contour
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____________________________________
33
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Appearance and Technique
33
____
____________________________________
____________________________________
Bend Test
33
____
____________________________________
____________________________________
TOTAL
99
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T-Joint Vertical Top Down 10 Gauge, Hard Wire
Shape and Contour
33
____
____________________________________
____________________________________
Appearance and Technique
33
____
____________________________________
____________________________________
Bend Test
33
____
____________________________________
____________________________________
TOTAL
99
____
Vertical Bottom UP T-Joint – 2 – Pass 1/4-inch Material, Core Wire
Shape and Contour
25
____
____________________________________
____________________________________
Appearance and Technique
25
____
____________________________________
____________________________________
Bend Test
25
____
____________________________________
____________________________________
Under Cut
25
____
____________________________________
____________________________________
TOTAL
100
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FINAL TOTAL
Total Test Time: 40 Minutes
298
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Signature of Examiner: ___________________________________