Platform lift up and down jerky, Overview of procedure, Check for these obvious conditions first – JLG 20VP (3120728) Service Manual User Manual
Page 97: Table 3-27. platform lift up and down jerky, Platform lift up and down jerky -37
SECTION 3 - TROUBLESHOOTING
3120728
– JLG Lift –
3-37
Platform Lift Up And Down Jerky
Overview Of Procedure
The following procedure suggests areas on the machine which might attribute to erratic movement of the platform during lift
up and down.
Check For These Obvious Conditions First:
• If mast is not running smooth or has tight and rough spots, refer to the Mast Section Rebuild.
• Hydraulic oil level in reservoir tank at full level.
• Hydraulic oil no milky (presence of water), or not foamy (full of air).
Table 3-27. Platform Lift Up and Down Jerky.
STEP
ACTION
SPEC
YES
NO
CONTROLS (ELECTRICAL)
1.
Is platform control, enable, up or down pad defective or worn out?
—
Replace pad
Go to Step 2
2.
Loose connections , ground and power.
—
Repair
connection
Go to Step 3
3.
Valve coils or solenoids keep opening and closing.
—
Repair Connec-
tion or Replace
Valve
Go to Step 4
4.
Problem internal to the MC-1 control box.
—
Replace box
Go to Step 5
HYDRAULIC
5.
Are the hydraulic valves working properly.
—
Replace Valve
Go to Step 6
6.
Pump drive cavitates.
—
Replace Pump
Go to Step 7
7.
Lift cylinder
—
Rebuild or
Replace Cylinder
—