REV BSection 4 • Repair Procedures June 20054 - 36 TMZ-34/19 Part No. 520756-2Valve Adjustments -Hydraulic Power UnitHow toAdjust the System Relief Valve1 Connect a 0 to 5000 psi / 0 to 350 bar pressuregauge to the test port on the hydraulic powerunit.2 Turn the key switch to ground controls and pullout the red Emergency Stop button to the onposition at both the ground and platformcontrols.3 Fully raise the primary boom.4 Press and hold the high speed function enablebutton and press and hold the primary boom upbutton and observe the pressure reading on thepressure gauge. Turn the machine off.5 Hold the relief valve adjusting screw and loosenthe lock nut.6 Adjust the relief valve screw. Turn it clockwiseto increase the pressure or counterclockwise todecrease the pressure. Refer to Section 2,Specifications.Tip-over hazard. Do not adjust therelief valve higher than specified.7 Hold the relief valve screw and tighten the locknut. Be sure the relief valve screw does notturn.8 Repeat steps 2 through 4 to confirm the reliefvalve pressure.9 Bleed the hydraulic system by raising theplatform to full height. If the pump cavitates orplatform fails to reach full height, add hydraulicoil until the pump is functioning correctly. Do notoverfill the hydraulic tank.Component damage hazard. Donot continue to operate themachine if the hydraulic pump iscavitating.HYDRAULIC POWER UNITa cdefba hydraulic tankb test portc pump motord pumpe lock nutf relief valve adjusting screw800-610-4101ActionRental.com
