Template Name: OML_1_col Template Date: 1994_04_22
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519 Telehandler
HYDRAULICS
BOOM LIFT CYLINDER TROUBLESHOOTING NOTE: If the boom will lift but will not lower, replace the counterbalance valve on the lift cylinder.
DANGER
Boom must be properly secured before any work is done on the lift cylinder or boom hydraulics. Does the boom lift without a capacity load?
NO Follow the Main Control Valve Pressure Pressure Troubleshooting procedure. Is the problem in the control valve?
YES Test the pressure at the test port on the battery tray. Retract the boom to the end of the cylinder stroke and hold. Does the pressure gauge read 3350 psi (230 bar)? YES Repair or replace the control components. YES Use an in-line flowmeter to test the pressure at the lift cylinder extend hose. Does the pressure gauge read 3350 psi (230 bar)?
YES Replace the counterbalance valve. Does the pressure gauge read 3350 psi (230 bar)?
NO Repair or replace the lift cylinder.
NO Follow the Main Control Valve Pressure Troubleshooting procedure. Does the pressure gauge read 3350 psi (230 bar)?
YES Remove the flowmeter.
YES Adjust the relief valve in the Main Control Valve. Open the load control valve of the flowmeter and hold the joystick in the boom lower position. Does the pressure gauge read 3350 psi (230 bar)?
YES Remove the flowmeter.
NO Remove and bench test the hydraulic gear pump. Does the hydraulic gear pump meet specifications?
NO Repair or replace the relief valve in the Main Control Valve.
YES Remove the flowmeter. 913302
NO Use an in-line flowmeter to test the pressure at the extend port of the lift cylinder. Does the pressure gauge read 3350 psi (230 bar) when cylinder is fully extended?
NO Repair or replace the hydraulic gear pump.
601-7
PRINTED IN U.S.A.
