844/642 Telehandler HYDRAULICS

Attachment Tilt Cylinder Troubleshooting

NOTE: If the tilt cylinder will roll back but not lower, replace the load counterbalance valve on the cylinder. Does the tilt operate without a load?

Test the pressure at the test port on MP on the.Follow the Control and Park Brake Pilot Presflow divider. Retract the boom to the end of thesure Troubleshooting procedure. Is the problem cylinder stroke and hold. Does the pressurein the controls? gauge read 3000 psi (207 bar)?

Repair or replace the control components.

Use an in-line pressure gauge to test the roll tilt up at the tilt cylinder. Does the pressure gauge read 3000 psi (207 bar)?

Repair or replace the tilt cylinder.Adjust the tilt pressure relief valve in the tilt control valve and retest the tilt up. Does the gauge read 3000 psi (207 bar)?

If the tilt does not work after adjustingRepair or replace the tilt control the tilt relief valve, repair or replace thevalve and/or the tilt relief valve. tilt cylinder.

Use an in-line flowmeter to test the pressure at the EF port of the priority flow divider. Does the pressure gauge read 3000 psi (207 bar)?

Adjust the relief valve in the Main Control Valve.Remove and bench test the hydraulic pump. Open the load control valve of the flowmeter andDoes the hydraulic pump meet specifications? hold the joystick in the boom lower position. Does the gauge read 3000 psi (207 bar)?

Remove the flowmeter.Replace the relief valve in the Main Control Valve.

Repair or replace the priorityRepair or replace the hydraulic pump. flow divider.

Template Name: OML_1_col 0-00000

Template Date: 1994_04_22

844/642 Telehandler HYDRAULICS

Frame Leveling Troubleshooting

Test the pressure at the JP test port on the flow divider. Does the pressure gauge read 400-425 PSI (27-29 bar)?

Test the pressure at the MP test port of the flow divider. Retract the boom to the end of the cylinder stroke and hold. Does the pressure gauge read 3000 psi (207 bar)?

Test the pressure at the priority flow divider IN port. Does the pressure gauge read 3000 psi (207 bar)?

Replace the priority flow divider.

Test the frame level hydraulic controller input pressure to the main valve. Does the gauge read 400-425 psi (27-29 bar)?

Remove and plug the hoses from the stabilizer cylinder and plug the stabilizer ports. Does the frame leveling work?

Repair or replace the hydraulic pump.

Replace tilt/level hydraulic controller.

Repair or replace the stabilizer cylinder. NO

Repair or replace frame leveling cylinder.

Template Name: OML_1_col 0-00000

Template Date: 1994_04_22

844/642 Telehandler HYDRAULICS

Steering Circuit Troubleshooting

Test the pressure at the SP test port on the flow divider. Cramp the steering fully to the right or left. Does the pressure gauge read 2500 psi (172 bar)?

Use an in-line flowmeter to test the pressure at port P of the Steer Mode Valve. Does the pressure gauge read 2500 psi (172 bar)?

If the problem is in front steer mode only,Repair or replace the repair or replace the front steer cylinder.Steering Control Valve. If the problem is in combination steer only, repair or replace the rear steer cylinder.

Test the pressure at the MP test port on the flow divider. Fully retract the boom and hold. Does the pressure gauge read 3000 psi (207 bar)?

Template Name: OML_1_col

Template Date: 1994_04_22

844/642 Telehandler

0-00000

G0805073

Template Name: OML_1_col 0-00000

Template Date: 1994_04_22

844/642 Telehandler

G0805074

Template Name: OML_2_col 0-00000

Template Date: 1994_04_22

844/642 Telehandler HYDRAULICS

Hydraulic System Testing

Pump Pressure Test

NOTE: Before performing any hydraulic test, check for any visible leaks or component damage. Repair or replace the leaking component before proceeding with the tests.

Step 1

Step 2

Warning

To prevent damage and/or personal injury when using an in-line flow meter for testing, ALWAYS be sure the load valve on the flow meter is fully OPEN before starting the engine.

Template Name: OML_2_col