BOOK 8 Flashcards
What is an accident?
- Anytime Department vehicle is involved in an accident with a third party vehicle or private property
- Anytime a Department vehicle is involved in an accident with another Department vehicle or Department property
- Anytime a Department vehicle strikes an animal, whether domesticated or non-domesticated
- Anytime a privately-owned vehicle of a member is involved in an accident during the members tour of duty, when such use is officially authorized
What is the main difference between gasoline and Diesel engines?
The two different methods of introducing fuel into the cylinder and igniting the fuel-air mixture. Fuel and air are mixed together before they enter the cylinder of a gasoline engine. Air alone enters the cylinder of a diesel engine
Pressure developed by the compression stroke is much greater in the diesel engine, in which pressures as high as ____ psi are common
500 psi
For each pound of pressure exerted on the air, there will be a temperature increase of about _____ F.
2 degrees F. At the top of the compression stroke (when pressure is highest), the temperature in the chamber will be about 1,000 degrees F.
It is very important that the clutch is not allowed to slip for more than about ____ seconds. When a clutch is slipped excessively the heat will quickly build up and damage the clutch assembly
1-1/2 seconds
What are the two primary functions of torque converters?
1) Acts as a fluid coupling to smoothly connect engine power through oil to the transmission gear train
2) It multiplies the torque, or twisting effort, from the engine when additional performance is desired
With the engine operating at full throttle, transmission in gear, and the vehicle standing still, the converter is capable of multiplying engine torque by approximately ___ to 1
2.2
What are the 3 elements of a torque converter?
- Pump
- Stator
- Turbine
TRUE OR FALSE: THE ENGINE CANNOT BE STARTED BY TOWING OR PUSHING. BEFORE TOWING OR PUSHING BEYOND A FEW BLOCKS, THE DRIVELINE MUST BE DISCONNECTED
TRUE
What is a Universal Joint?
A universal joint is a flexible coupling between two shafts that permits one shaft to drive another at an angle to it. This unit is necessary to provide flexibility in the power train as the vehicle travels over uneven surfaces
What is a Slip Joint?
As the vehicle travels over uneven ground, the distance between the transmission and the rear-end varies. A slip joint provides the necessary telescopic action in the drive line. It consists of a male and a female spline, a grease seal, and a lubrication fitting. The male spline is an integral part of the propeller shaft and the female portion is fixed to the universal joint
What is the Propeller Shaft?
Also known as Drive shaft, or Drive line. This device carries the torque from the transmission to the rear-end. This shaft may be solid or tubular type. The stress in the shaft varies from zero at the axis to a maximum at the outside. Since the center of the shaft resists only a small portion of the load, hollow shafts are used whenever practicable. A solid shaft is stronger than a hollow shaft of the same diameter, but a hollow shaft is stronger than a solid shaft of the same weight.
What is the Final Drive?
Its function is to change the direction of the power that is transmitted by the propeller shaft through 90 degrees to the driving axles
A common final drive ratio for L.A.F.D. apparatus is, ____ to 1
4.11 to 1. That is approximately four revolutions of the propeller shaft to one revolution of the rearwheels
What is a Differential?
The differential is the unit that allows the axles to turn at different speeds from each other while still pulling the apparatus. As a vehicle is driven around a curve, the outer wheels must travel faster than the inner wheels because they travel further in the same amount of time
TRUE OR FALSE: Although the transmissions used by the LAFD are true automatic transmissions they will give much better performance, smoother operation, and more longevity if they are operated as if they were a “clutchless” manual shift transmission.
TRUE
When should an apparatus pre-check be performed?
- Each morning at relief
- Any time during the day when a change of relief is required
- After each incident when the apparatus or its equipment is used
Why should fuel be kept to the full level whenever possible?
Because of condensation of moisture inside a partially filled fuel tank
When shall daily checks be conducted?
As soon as practical following relief
Any joint not equipped with a lubrication fitting; and of a design requiring lubrication, shall be lubricated ________ with a light coat of _________.
Monthly; engine oil
When draining tanks, which tank should be drained first?
The primary tank because it is the first reservoir that the air enters from the compressor and this will allow all moisture and foreign material to be blown out
A Heavy Apparatus is ____ cubic inches or over
465
What is Brake Fade?
Improper use or excessive braking will cause the brakes to heat up. “Brake fade” is one of the worst consequences of heat due to excessive, braking. As heat builds up, the lining on the brake shoes begin to melt. As it melts, it turns to liquid that lubricates the space between the shoes and the drum causing the brake drums to glaze. This same heat will cause the drums to expand causing the brake shoes to travel farther to reach the brake drum. It will be necessary to increase pedal pressure in order to stop or slow the vehicle
Depending on the type of vehicle, it will take between ___ to ___ second for the air to reach the brakes after you press the foot pedal. This lag means you have to start braking a little earlier than would be required in a vehicle with hydraulic or mechanical brakes
1/4 to 1 second