190302aB Flashcards
Wheeled Equipment Steering Fundamentals and Service Part B
What kind of hyd steering system is on a skid steer?
closed loop system
characteristics of the steering pump on a skid steer?
reversible, variable displacement piston pump. hydrostatic pump
Characteristics of a hydrostatic pump?
swashplate can go to zero angle (neutral)
swashplate can go overcentre
characteristics of a hydraulic motor on a skid steer?
swashplate can’t go to zero angle, can’t go over centre
When is max torque created between the pump and the motor from swash plate angle?
pump swash plate minimum angle, motor swash plate max angle
when is max speed created between the pump and motor from swash plate angle?
pump swash plate max angle, motor swash plate min angle
What is the directional control valve used for on a skid steer?
lift cylinders, bucket cylinders, aux attachments
What are the pressure controls used on a skid steer?
dcv relief, charge pressure relief, steering system relief
Where are the case drain circuits?
on the steer pump and steer motor. allow leakage oil to go back to tank
what micron rating is the spin-on filter for a skid steer?
10 micron
machines that use a skid steering system have all wheels, or both tracks fixed in a straight ahead position
T or F
T
How does the hydraulic pressure in the steering system act as a service brake?
the joysticks are spring-loaded to a central position when operator releases pressure on the control
What is the major cause of hydraulic steering system problems related to?
contaminated hydraulic oil
When do contaminants typically enter the system?
when the hyd oil/filter is being changed, as well as when aux connections are being used
A hydraulic oil charge pressure circuit delivers low pressure hyd oil to the hyd steering pump. in addition, oil is supplied to the control valve to activate the hyd attachments
T or F
true
