powershift test and service Flashcards
what are the five steps in the trouble shooting process
gather information - talk to the operator - perform visual inspection - perform operational tests - test and analyze the system with hydraulic equipment
what are the three methods for gathering information
service manual - service bulletins - operators manual
talking to the operator is one of the best sources of
information about the machine fault
visual inspection
look listen smell hear
why is warming up the oil important during trouble shooting
because if you test with cold oil the fault might not even show up
what is a very effective method of warming up oil
torque stall
how long should a stall test be preformed
30 seconds
stall test speed is lower than specification
low engine power - torque converter stator is slipping ( freewheeling )
stall speed is higher than specification
excessive power on engine - slipping trans clutches - torque converter cavitating
what are some basic safety precautions before pressure testing
stop the machine on level ground - lower or mechanically block all work equipment - apply parking break
pressure gauge should be
double the anticipated pressure rating
what are the three hydraulic circuits in a transmission
application - torque converter charging - transmission lube
what is a good method for checking for excessive internal leakage in a clutch application circuit
engine running at low and high idle while cycling through gears
when installing a pressure gauge in the torque converter inlet . a low pressure reading is taken the common causes could be
restricted pump inlet or worn pump - excessive leakage in clutch application circuit - excessive leakage in torque converter circuit
the governor circuit provides a pressure signal that is proportional to
machine ground speed
