retarders

Question 1

hydraulic retarders are used to

Answer 1

reduce the speed of equipment through the use of hydrodynamic breaking

Question 2

hydraulic retarders can be activated on a downhill grade to prevent

Answer 2

the engine from overspeeding and reduce the use of the service breaks

Question 3

a hydraulic retarder is only a supplementary breaking system and will only

Answer 3

slow the machine not stop the machine

Question 4

hydraulic retarders are identified by

Answer 4

where they are put in the machine

Question 5

what are the three locations for hydraulic retarders

Answer 5

input - output - driveline

Question 6

input retarders

Answer 6

located between the torque converter and the transmission

Question 7

output retarders

Answer 7

installed on the transmission output shaft

Question 8

output retarders will exert force

Answer 8

directly on the drive line and will act independently of changes in engine rpm or transmission gear selection

Question 9

what are some output retarders equipped with a multi disc clutch pack

Answer 9

to eliminate the time delay for the retarder to fill with oil before breaking can begin

Question 10

equipment hydraulic retarders is less effective at

Answer 10

low speeds

Question 11

remote mount retarders

Answer 11

installed on the drive line

Question 12

what are the components that make up a retarder

Answer 12

rotor - housing ( stator ) - oil pump ( supply circuit ) - cooler - control valve - wet brake - accumulator

Question 13

what component is located between the housing and the stator of a retarder that has bent or angled vanes

Answer 13

retarder rotor

Question 14

what is another name for the housing on a retarder

Answer 14

stator

Question 15

why is it important to cool the oil of a hydraulic retarder

Answer 15

because the sheering of the oil during hard applications can cause the temperature to rise very fast

Question 16

what are the three hydraulic retarder control methods

Answer 16

manual operator - air over hydraulic - electronic

Question 17

what are the basic switches for an automatic control circuit in a hydraulic retarder

Answer 17

ignition - mode selection switch or lever - clutch position switch and trans gear indicator - fuel control position indicator ( throttle position sensor )

Question 18

what will extend the service life of the hydraulic retarder and maintain oil quality

Answer 18

being able to modulate retarder control

Question 19

what is a wet break

Answer 19

a multi disc clutch pack used to start the retarding process

Question 20

wet breaks can also be applied when

Answer 20

the vehicle is traveling very slow

Question 21

why do some retarders use accumulators

Answer 21

as a fast fill method

Question 22

why do off road equipment seldom use accumulators

Answer 22

because the charging pumps are large enough for a fast fill without an accumulator

Question 23

the hydraulic retarder turns kinetic energy into

Answer 23

heat energy from sheering the oil

Question 24

the hydraulic retarder control circuit will allow the operator to

Answer 24

apply the service breaks at the same time to maximise breaking effort and safely stop the machine

Question 25

when the hydraulic retarder has been mounted between the engine crankshaft flange and the flywheel what must be required

Answer 25

a lock up clutch

Question 26

when is a retarder most efficient

Answer 26

when it is connected directly to the driveshaft

Question 27

what is the purpose of a synchronizing valve

Answer 27

to prevent engagement of scraper transmission until they are in the correct relation

Question 28

if the hydraulic retarder is to small for the application

Answer 28

excessive heat will be generated and oil will deteriorate very quickly

Question 29

what are some computer controlled inputs that may be controlled by the power train ECM

Answer 29

throttle position sensor - retarder oil temp sensors - shaft speed sensor - retarder enable device - brake application pressure sensor

Question 30

computer controlled outputs that may be controlled by the power train ECM are

Answer 30

retarder control valve solenoid - warning lights - brake lights - over temperature light

Question 31

shiny steel particles found during T/S

Answer 31

possible pump wear or failure

Question 32

aluminium particles found during T/S

Answer 32

retarder rotor wear

Question 33

rubber particles found during T/S

Answer 33

seal or hose failure

Question 34

iron or steel chips found during T/S

Answer 34

broken components

Question 35

if unusual particles are found during inspection of mag screen or filter

Answer 35

all oil circuits and components must be thoroughly flushed and cleaned before returning the retarder to work