SFN-20240502A Hydraulic Diagnostics

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TICO Document #: SFN-20240502A

Description of Procedure: Hydraulic Diagnostics

Units Affected: N/A

Parts Required: N/A

Planned Labor: N/A

Prerequisite:

  • Checked hydraulic tank for proper fluid level

  • Fluid is not visually contaminated and does not contain any debris

  • Both ball valves are in the open position for the supply line to the pump and filter

Electrical Diagnostics for Directional Control Valve

Instructions:

  1. Check the voltage at the actuators for the directional control valve with truck running, but with the joy stick on the normal position. Is there any voltage reading at either of the actuators? If there is voltage on either actuator, this indicates a problem with the control circuit.

  2. Determine if there is a short and holding power to each actuator.

  • With the joystick in the up position, check for voltage on the down actuator. There should be no power.

  • With the joystick in the down position, check for voltage on the up actuator. There should be no power.

  1. Perform an Ohms test on each actuator. What are the readings for each coil ?

    1. Up coil ohms reading _______________

    2. Down coil ohms reading ______________

  1. If all electrical checks out, then we need to move to Hydraulic pressure testing. Using a 5000 psi pressure gauge, follow the pump pressure testing point and recommended pressure readings.

Hydraulic Pump Pressure Test

Hydraulic Pump Test Readings

Pressure testing is performed at the hydraulic pump pressure line to the DCV.

With the engine at 1500 RPM and the lift cylinder at full lift, what is the hydraulic max pressure reading? ____________________psi (Prince DCV 2800 psi) (Cross DCV 2300 psi)

Advise on your findings in your TICO Edge case.