Service Technician Skill / Knowledge Test

Select a choice

A) Are generally not required in an equipment shop.

B) Are required to be given to a customer when a machine is returned.

C) Are useful in troubleshooting electrical problems.

D) Should be returned to the manufacturer when a new piece of equipment is sold.

E) Describe proper safety and handling techniques of Various chemicals and fluids

Select a choice

A) it has a class number as opposed to grade marks on the head.

B) It says Ametric @ right on the bolt.

C) only non-US manufactures use metric fasteners.

D) the heads always have 12 points as opposed to 6 points.

E) There is no Aclass@ or Agrade@ marking on the head.

Select a choice

A) Must be recycled or disposed of as a hazardous material

B) Must be returned to the customer along with any used parts

C) Should be filtered and reused in an engine

D) Is a very effective dust suppressant for gravel driveways

E) is generally disposed of through the sanitary system

4. The head of the bolt shown below indicates:

Grade 5

Select a choice

A) The bolt is metric.

B) The bolt is Grade 3.

C) The bolt was made I the US.

D) The bolt is Grade 5.

E) Only 6-point sockets are to be used on this bolt.

5. 0 - 1" micrometer is used to take a measurement on a wrist pin for wear. The micrometer appears as shown. The pin diameter is:

Select a choice

A) 0.115"

B) 1.1115"

C) 0.015"

D) 0.215"

E) 0.190"

Use the diagram below for Questions 1 and 2.

gears

Select a choice

A. 500 rpm

B. 1000 rpm

C. 200 rpm

D. 4000 rpm

E. None of the above

Select a choice

A. 500 rpm

B. 1000 rpm

C. 2000 rpm

D. 4000 rpm

E. None of the above

3. Which of the following is the proper name for a toothed belt drive System?

Select a choice

A) Serpentine

B) Power Band

C) Variable Pitch

D) Synchronous

E) Timing

Select a choice

A) the longer the links are.

B) the higher the allowable load o the chain.

C) the less the chain needs to be lubricated

D) the faster the chain can run.

E) both A and B.

Select a choice

A) Increase belt life.

B) Reduce belt life.

C) Increase pulley life.

D) Make the driven attachment operate at a higher speed.

E) Have no effect on the belt or bearing life.

1. Which of the following list of engine oils is the best suited for a wide range of operating temperatures?

Select a choice

A) SAE 20

B) SAE 20W

C) SAE 30

D) SAE 50

E) SAE 10W-40

Select a choice

A) may result in burned valves.

B) will make the engine run too hot.

C) may result in excessive crankshaft wear.

D) will make a cold engine hard to start

E) will cause excessive valve train noise.

3. A Catalyzed DPF (Diesel Particulate Filter) requires oil with which of the following characteristics?

Select a choice

A) 0% Sulphur

B) High viscosity index

C) Low ash content

D) High alkalinity

4. A 4 stroke cycle diesel engine operates at 1800 rpm. The injector In each cylinder delivers fuel to the cylinder_ times every second:

Select a choice

A) 15

B) 30

C) 60

D) 450

E) 900

Select a choice

A) provide easier starting.

B) facilitate troubleshooting of compression problems.

C) provide a convenient place to install a compression tester.

D) make the engine run more smoothly.

E) permit use of lower octane or cetane fuels.

1. A vacuum pump is being used to evacuate a system prior to charging. The system has been successfully evacuated. After the vacuum pump is shut off and the valve to the pump is shut off, the vacuum gauge shows a slow, but steady loss of vacuum, Which of the following is true?

Select a choice

A) There is a leak somewhere in the system that must be found and repaired.

B) This is normal. The system should be charged.

C) The vacuum pump is defective.

D) The desiccant in the dryer is saturated with water and must be Replaced.

2. Which of the problems listed below will cause the manifold gauge readings shown in the illustration?

Select a choice

A) Refrigerant overcharge

B) Low refigerant

D) Expansion valve stuck closed

E) Restricted condensor airflow

Select a choice

A) just above freezing.

B) as high as possible.

C) approximately the same temperature as the engine coolant.

D) slightly hotter than the condensor.

E) inconsequential. Evaporator temperature doesn't matter.

Select a choice

A. is located in the cab

B. is a part of the low side of the system

C. receives the refrigerant after it leaves the expansion valve

D. will be damaged if adequate lubricant is not used in the charge

E) is located in the engine radiator and is cooled by the engine fan air flow

5. To charge an air conditioning system while it is running, the
refrigerant should be added to:

Select a choice

A) the high side.

B) the low side.

C) either side.

D) both sides simultaneously.

E) neither side. Shut the system off before charging.

1. What spool position allows oil to freely flow in and out of a connected cylinder in either direction?

Select a choice

A) Raise

B) Lower

C) Neutral

D) Power beyond

E) Float

Select a choice

A) the dirt holding capacity of the filter.

B) the filter change interval.

C) the flow rate of oil that can pass through the filter.

D) the size of particles that will be caught.

E) the number of layers of filter media used.

3. How much horsepower would be required to pump 20 gpm at 1500 psi? Hydraulic horsepower= P (psi) x Q (qpm)/1714.

Select a choice

A) 12.8

B) 15.3

C) 16.8

D) 17.5

E) 20.00

Select a choice

A) control cylinder speeds.

B) prevent over-pressure in the system.

C) maintain the desired flow rate.

D) keep the oil cool

E) prevent operation if the filter becomes plugged.

5. In the diagram shown below, the valve immediately to the right of the pump is a ______ valve.

Select a choice

A) check

B) flow control

C) pressure relief

D) filter bypass

E) low divider

Select a choice

A) air -fuel mixture to be too lean.

B) air􀀣fuel mixture to be too rich.

C) Engine to run too fast.

D) Connecting rod to fail.

E) Both B and C are correct.

2. Technician A says old antifreeze may cause corrosion build-up in the cooling system. Technician B says some original equipment manufacturers (OEM) recommend that the coolant be changed at specified intervals. Who is right?

Select a choice

A) A only

B) B only

C) Both A and B

D) Neither A nor B

3. When draining used engine oil from a 4 stroke cycle engine, it is best to:

Select a choice

A) drain the oil with the engine cold so that all the oil is in the bottom of the crankcase.

B) drain the oil after running the engine so the oil holds contaminants in suspension.

C) only drain part of the oil so the crankcase never goes completely dry.

D) Make sure the piston is on top dead center.

E) Drain the oil either hot or cold.

4. Diesel fuel left in an engine that has not run for an extended Period of time:

Select a choice

A) Is not a problem.

B) Should be diluted with fresh fuel before starting.

C) Will not burn.

D) May have water in it due to condensation.

E) Will burn fine but cause the engine to smoke excessively.

5. An appropriate check or inspection to perform on an engine which runs hot is:

Select a choice

A) injector opening pressure too high.

B) coolant thermostat stuck open.

C) Fuel shut-off lever partially pulled out.

D) Clogged air filter.

E) Clogged radiator fins.

1. An ammeter is used to test a charging circuit. Is should be Connected:

Select a choice

A) in series in the wire from the charging system.

B) in series in the battery ground wire.

C) in parallel with the key switch.

D) in parallel with the wire from the charging system.

E) between both battery terminals.

Select a choice

A) voltage.

B) a defective battery.

C) current flow in a wire.

D) an open circuit.

E) condition of the starter.

Select a choice

A) in series with the circuit.

B) in parallel with the circuit.

C) from the battery ground terminal to a ground on the machine.

D) from the hot battery terminal to the charging circuit.

E) only in the ignition system circuit.

4. When current flows in both directions in a conductor, this is called:

Select a choice

A) direct current.

B) alternating current.

C. either direct or alternating current.

D) an open circuit.

E) a short circuit.

5. The resistance of a switch increases due to corrosion of the contacts. If voltage remains constant, the current flow through the switch will:

Select a choice

A) decrease.

B) increase.

C) Remain the same.

D) Stop completely.

E) Create s short circuit.

1. A variety of shut-down and safety devices are used on diesel powered equipment. Which of the following is NOT a possible reason/cause for a diesel engine to shut down?

Select a choice

A) Key switch is turned off.

B) Fuel Akill@ knob is pulled out.

C) Operator leaves the seat and opens the seat switch.

D) Engine oil level gets too low.

E) Parking brake is activated with the ground drive transmission in neutral.

Select a choice

A) color of exhaust smoke.

B) compression testing.

C) visual inspection.

D) both A and B.

E) A, B, and C.

3. Which of the following should be the first step in diagnosing an engine performance concern?

Select a choice

A) Discussing concern with the vehicle owner

B) Retrieve diagnostic trouble codes

C) Check for symptoms in the on-line service manual

D) Road test the vehicle

Select a choice

A) diesel engines do not use governors.

B) the governor is an internal component in the injection pump.

C) the governor is driven directly off the crankshaft.

D) the governor will fail to function if the drive belt breaks.

E) governors are optional, but most engines have them.

Select a choice

A) high intake vacuums.

B) decreased horsepower.

C) harder starting.

D) A and B.

E) A, B, and C.

Electrical Circuits and Schematics

Use Diagram E-1 below it will help you answer questions 1, 2, and 3.

1) The charging system is to be checked with a volt-ohm meter for proper operation. The battery voltage is 13.6 volts when the engine is shut off. Voltage at terminal AB@ is 14.2 volts when the engine is running at mid-speed. Which of the following would be an accurate conclusion regarding the charging system?

Select a choice

A) The alternator is OK, but the regulator is defective.

B) The alternator and regulator are both OK, but the battery needs to be replaced.

C) These readings are normal. everything is OK.

D) The regulator is overcharging the battery.

E) No conclusions can be drawn from this information.

Select a choice

A) controlling the voltage supplied to the stator coll.

B) controlling the voltage supplied to the rotor coil.

C) controlling the diode bank.

D) sending excess alternator output current directly to ground.

E) grounding the center (N) wire of the stator coil.

3) The charging system seems to be operating properly. However, the machine battery slowly discharges when the machine is idle. Eventually, the battery drains completely. Which of the following could cause this problem?

Select a choice

A) The rotor coil is short circuited to ground.

B) The stator coil is short circuited to ground.

C) The regulator is discharging through the charging lamp circuit.

D) The alternator bearings are worn.

E) The diode bank is defective.

4) Battery voltage of 12.9 volts is read with a volt ohm-meter between checkpoint A and ground. There is no voltage at checkpoint L. Which of the following is responsible for this situation?

Select a choice

A) The instrument fuse is blown.

B) The key switch fuse is blown.

C) The key is turned off.

D) The park brake is not set.

E) Insufficient information to identify the exact cause.

5) The starter falls to turn the engine over when the key switch is turned to AStart@. The battery has adequate voltage. The same voltage is also read at points C, F, and H, and I when the switch is held to the AStart@ position. The problem Is:

Select a choice

A) The neutral switch is open.

B) The starter solenoid is defective or has bad connections.

C) The key switch fuse is blown.

D) The starter is defective or has bad connections.

E) The key switch is not functioning properly.

Thank you for taking our Service Technicians Skill / Knowledge Test.