Platform lift up and down jerky, Overview of procedure, Check for these obvious conditions first – JLG 15VPSP Service Manual User Manual

Page 87: Table 3-27. platform lift up and down jerky, Platform lift up and down jerky -33

SECTION 3 - TROUBLESHOOTING

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– JLG Lift –

3-33

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

CONTROLS (ELECTRICAL)

Is platform control, enable, up or down pad defective or worn out?

—

Replace pad

Go to Step 2

Loose connections , ground and power.

—

Repair

connection

Go to Step 3

Valve coils or solenoids keep opening and closing.

—

Repair Connec-

tion or Replace

Valve

Go to Step 4

Problem internal to the MC-1 control box.

—

Replace box

Go to Step 5

HYDRAULIC

Are the hydraulic valves working properly.

—

Replace Valve

Go to Step 6

Pump drive cavitates.

—

Replace Pump

Go to Step 7

Lift cylinder

—

Rebuild or

Replace Cylinder

—