JLG 20VP (3120728) Service Manual - Manual (Page 100)

SECTION 3 - TROUBLESHOOTING
3-40 – JLG Lift – 3120728
Platform (Mast) Descends Too Slowly
Overview Of Procedure
The following procedure examines the mast some hydraulic components for obstructions and defects.
Table 3-30. Platform (Mast) Descends Too Slowly.
STEP ACTION SPEC YES NO
1. Check mast slide pads shimmed to tight. — Reshim Mast Go to Step 2
2. Is there an obstruction in the mast?
—
Remove
Obstruction
Go to Step 3
3. The lift cylinder packing could be too tight in the bore of the cylinder
barrel.
—
Rebuild or
Replace Cylinder
Go to Step 4
4. Check the flow valve on the extend hydraulic line for a restriction, i.e.
dirt.
—
Clean or Replace
Flow Valve
Go to Step 5
5. Check if the lift down valve is opening completely.
—
Clean or Replace
Valve
Go to Step 6
6. Is there a restricted hydraulic line (smashed)?
—
Replace Hydrau-
lic Line
—