hydraulics 203 Flashcards
what is the pout point of hydraulic fluids
the lowest temp at which the fluid will flow
what is the imperial unit of force
pounds
what is pi
3.14
what is created when pressure is less then atmospheric
vacuum
what size is hydraulic steel tubing that is labelled -12
outside diameter of 3/4
hydraulic fluids can be cooled by…
air and water
how are hydraulic hoses sized
ID
depth filters are
non-woven
what filter rating describes the size of particles that the filter is designed to remove
absolute rating
what is the formula used to determine a filters beta rating
upstream particles/downstream particles
what is the most common directional valve in a modern hydraulic system?
spool
What is the function on a pump
create flow
What component is used to support the driveshaft on a vane pump
bearing
What is the basic operating principle that can be applied to all hydraulic valves
control hydraulic flow
What is the purpose of a back pressure EGR valve
control the flow of exhaust gases to the intake mixer
How should a hydraulic cylinder be stored?
hung upright
What type of hydraulic cylinder is actuated by fluid in both extension and retraction
dual acting
If a customer recieves the wrong part what is the first thing you should do?
identify what is wrong about the part
What device converts hydraulic energy into rotary mechanical energy
motor
What related item should be sold with a replacement hydraulic motor
Fluid
Where is the greatest force exerted on a three stag telescoping cylinder
first stage
2 Types of single acting cylinders
Ram and Piston
What part connects left hand knuckle to the right hand knuckle
cross-tube, Tie rod
How are suspension systems categorized
type of energy absorbing device
The weight of all parts that is supported by the springs is referred to as…
sprung weight
What is the cause of spring wind up in a longitudinal leaf spring suspension
drive and brake
What is used with a leaf spring suspension in order to provide a better ride than that of a solid mount
equalizer beam
What type of spring is used to help carry a heavy load
auxiliary spring
When would a hose be used instead of tubing
offers more flexibility
what is the purpose of shock absorbers
increase ride comfort
What suspension system offers the most comfortable ride
air bags-air suspension
Which steer system has the rear tires turning on the same track as the front tires
co-ordinated
which component supplies the power steering system with hydraulic energy
pump
What steering configuration involves a machine composed of two rigid frames which a turning point
aticulated
How much additional power will be required to stop a vehicle if both the weight and the speed are both doubled
increased 8 times
what is lag time
time required for the air system to apply the brakes
What term describes the amount of friction between vehicle tires and road surface
traction
What portion of stopping time is influenced when brake lining temperature is excessive
braking time
what does brake fade refer to
decreased braking force due to decreased coefficient of friction
What is not identified by outer edge code
GAWR
Why are vehicles that comply with CMVSS 121 standard known as having dual braking system
they have 2 separate service brake circuits
What type of brake materiel generates the least amount of dust
ceramic
What will affect the brake lag time on an air brake system
air restrictions, brake adjustments
What is the affective diaphragm area of a series 24 brake chamber
24 square inches
What colour is the park control valve
yellow
Where would the required information be found to supply a replacement compressor
nameplate
What is the advantage of disc brake over drum brake
disk brakes are less prone to brake fade
Where is the trailer supply valve located
by the park and trailer knobs (5)
Who is the regulating body that oversees the air brake safety standards
federal government
What is required on all brake lines sold in Canada
DOT markings
Why is water a major concern in an air brake system
may freeze
What is the purpose of the primary service brake circuit in an air brake system
control drive axle brakes
What brakes must be applied 1st in order to maintain a straight line as a vehicle stops
trailer rear
What bis happening when a compressor is in the unload cycle
inlet valves are held open
What components supply the air used to release the park/emergency brakes
Primary or secondary tank
How does the relay valve affect lag time?
valve speeds up brake application and release
What component houses Bothe the park control valve and the trailer air supply valve
control module
Why are double compartment tanks becoming more popular
lighter weight
What controls the operation of the compressor in an air brake system
the governor
What is the purpose of an alcohol injector
contamination control
Which valve in the air brake system speeds up the application of the steering axle brake
quick release valve
What component should be replaced at the same time as the is compressor
governor
How do ABS systems prevent wheel lock up
they monitor wheel speed and modulate brake application
What was a disadvantage to a pre-121 trailer brake circuit
no emergency brakes if trailer system failed
What is a output device of ABS
brake modulator valve
What is the purpose of the emergency brake in an air brake system
Mechanical means to park
