CD Industrial Group Inc.

Simulations & Hands-On Learning Challenges
Level II
4 Day
Instructor-Led Course

Loaders & Graders

Learn to:

  • Interpret complex loader and grader schematics
  • Test for correct pump standby and margin pressures
  • Verify normal and faulted steering systems
  • Describe brake component and system functions
  • Measure PWM proportional valve solenoid current

In this customized course, heavy duty mechanics, heavy equipment technicians, shop leaders, planners and reliability specialists learn the typical system designs for loaders and graders. Various circuits from Caterpillar, Komatsu, John Deere and Volvo machines are covered with on-screen simulations and Live Schematics.

Drawing on materials from our courses How to Maintain & Troubleshoot Hydraulic Systems and Advanced Mobile with Load Sense Hydraulic Troubleshooting, participants learn to maintain and troubleshoot loader and grader systems for maximum availability and reliability. A method of analysis for determining faults is taught, as is our Ten Step Troubleshooting Process. Schematic reading and safe work practices are core topics throughout.

Orbitrol Steering and Articulation

Objective: Explain the functions of a conventional hand metering unit (HMU)

Activities: Map out flow paths through steering circuits to aid troubleshooting

Know the priority valve functions cold

Electro-Hydraulic Joystick Steering

Objective: Identify the components of a typical joystick steering circuit

Activities: Test electronic proportional steering valves and position transducers

Solidify your skills with steering servo cylinders

Loader Boom Lift and Ride Control

Objective: Identify the components of the boom lift and bucket tilt circuit

Activity: Identify valve centre features as well as load check valves and shock valves

Decode Komatsu WA and Caterpillar ride control circuit functions

Loader and Grader Hydraulic Brakes

Objective: Describe the components and functions of hydraulic brake systems

Activities: Interpret brake accumulator charging circuits and slack adjusters

Know the function of the brake pedal as a pressure reducing valve

Multi-Section Valves

Objective: Identify the unique proportional valve components in use for load sense hydraulics

Activities: Identify pressure compensators in valve, and pilot operated checks

Know the load sense shuttle (resolver) network

Pump Standby and Margin Pressures

Objective: Interpret load sense (flow compensating) pump functions

Activities: Perform pump standby and margin pressure tests

Know your pump up-stroke (swivel-in) and de-stroke (swivel-out) functions

Pilot Valves and Joysticks

Objective: Explain the basic principles of pilot valves (controllers)

Activities: Identify test points for critical pressure tests

Know the function of the joystick as a pressure reducing valve

Auxiliary Implements

Objective: Interpret the circuits for grader rippers and loader bucket accessories

Activities: Confirm the sequence of valve operations

Identify cylinder pressure shock relief valves

Critical Pressure Controls

Objective: Identify critical system pressure controls and their settings

Activities: Adjust the functions of the Caterpillar H series combination valve

Know the maximum load sense pressure relief valve

Where does this class fit in?

Loaders & Graders is a specialty construction and mining class, along with Dozers & Excavators. If you enjoyed this class, consider taking your troubleshooting further with our general hydraulics course, How to Maintain & Troubleshoot Hydraulic Systems.

Want to book this course? Get in touch: