844/642 Telehandler HYDRAULICS

Step 57

Retract the boom to the end of the extension cylinder stroke and hold the joystick in the RETRACT position. The pressure gauge should read 3000 psi (207 bar).

If the pressure is less than 3000 psi (207 bar), go to Step 46 of the EXTENSION CYLINDER QUICK TEST.

If the pressure is 3000 psi (207 bar), proceed to the next step.

If the pressure is more than 3000 psi (207 bar), go to the Main Control Valve Pressure Relief Test and Adjustment section of this manual before proceeding to the next step.

Extension Cylinder Counterbalance Valve Direct Test And Adjustment

Step 58

Shut off the engine. Remove the pressure gauge. Remove the hose (1) from the retract bulkhead fitting (2). Install a 5000 psi (345 bar) pressure gauge (3) between the hose (1) and bulkhead fitting (2).

Step 59

Start the engine and run at 1000 RPM. Extend the boom approximately 6 feet (2 meters). Watch the pressure gauge as the boom is slowly retracted. The gauge should read 1500 psi (103 bar) as the boom is retracted.

If the gauge is not at 1500 psi (103 bar), proceed to the next step.

Template Name: OML_2_col

Template Date: 1994_04_22