JLG 600 AJ Drive / Break problem

Hi ,

Have a problem with machine ( 4x4 ) 600 AJ Model , when you drive the machine forward and reverse , it suddenly stop/break very harsh and hard , the hydraulic pump makes e high pressure noise and the machine grinds to a halt , if you release and apply the foot switch it drives again , this problem does not come up in creep speed , if you turn the speed control (yellow knob) just a little bit up to increase speed , then the fault occurs. Some suggestions was that the oil are hot maybe old and the brakes loose oil pressure and are applied during operation , also suggested that maybe the some of the wheel drive motors are by passing , oil change suggested ect,,.... difficult one to solve this time as the fault is intermitted ,
can anyone please advise ??

Theuns

Possible that you're losing contact in the footswitch? I know drive functions tend to bounce the platform the most and releasing the footswitch stops every function immediately. If you have a JLG Analyzer you should be able to retrieve whatever faults are showing up and might help you pinpoint the source of the issue.

You also might try decreasing the decelleration in the Jlg analyzer too.