suspension systems

Question 1

suspension systems must

Answer 1

have a specific carry capacity .in relation absorb and transit torque to the vehicle frame . provide cushion effect . position axle assembly accurately to the drive line . allow axle assembly movement during operation . allow each axle of a tandem or tri tandem unit to move independently of each other

Question 2

the tractor scraper is a unit that was designed to carry material a distance of

Answer 2

100 to 1000 meters

Question 3

a tractor scraper is a two section machine that consist of

Answer 3

a front tractor section that includes the operators compartment and a rear bowl section

Question 4

what does the hitch assembly allow the tractor scraper to do

Answer 4

articulate . as well as tilt slightly side to side

Question 5

what is a stiffneck hitch

Answer 5

does not allow any vertical movement in a the hitch

Question 6

cushion hitch hydraulic load cylinder uses what to control vertical movement in a scraper

Answer 6

hydraulic action in combination with compressed nitrogen gas from the accumulators

Question 7

are the cushion hitch type suspension systems adjustable

Answer 7

yes the operator can control the cushioning effect by engaging the cushion control

Question 8

the articulated haul truck was designed to haul material how far

Answer 8

300 to 2000 meters

Question 9

smaller haul trucks use what type of suspension

Answer 9

rubber block type suspension

Question 10

larger haul trucks use what type of suspension

Answer 10

hydropneumatic type suspension

Question 11

large haul trucks with only one axle use what to keep the drive axle housing centered left to right

Answer 11

a pan hard rod

Question 12

regardless of the type of suspension system they all must control

Answer 12

excessive vertical movement over rough terrain

Question 13

when a cushion hitch is locked down to allow for a flatter grade and is not returned to cushion when hauling dirt

Answer 13

the scraper can develop a loping motion

Question 14

the cushion hitch hydraulic system with exception of the hydraulic reservoir is

Answer 14

completely separate from the rest of the machines hydraulic system

Question 15

a single engine tractor scraper has only what two positions for the cushion hitch

Answer 15

lockdown - cushion ride

Question 16

if a twin engine tractor scraper has a push pull (bail system ) what are the control lever positions

Answer 16

bail down , lockdown ( for push pull loading rear machine or parking ) 
bail up , lockdown ( push dozer loading  , lead unit or finishing 
cushion ride ( traveling )

Question 17

what is the purpose of the leveling valve is the cushion hitch system

Answer 17

stops oil flow to accumulator and cylinder once leaf spring and yoke reach proper ride height

Question 18

how long must the engine be shut off to allow accumulators to bleed down

Answer 18

five minutes

Question 19

why must you pour hydraulic oil into a new accumulator cylinder then run the unit before filling with nitrogen

Answer 19

to purge the air from the accumulator

Question 20

dry nitrogen must be what % pure

Answer 20

99.8%

Question 21

what do A frames provide

Answer 21

longitudinal support and transfer the forces created by wheel torque

Question 22

what is another name for hydropnumatic suspension

Answer 22

strut

Question 23

what limits strut twist

Answer 23

wear strips or wear bars

Question 24

what is a payload weight sensor

Answer 24

a pressure sensitive sensor place in a strut to monitor nitrogen pressure in relation to the load placed on the truck

Question 25

you should never check the oil in a suspension cylinder until

Answer 25

the nitrogen has been released

Question 26

when one suspension cylinder must be charged

Answer 26

both suspension cylinders must be charged at the same time