| Possible Cause #1 |
Little or no hydraulic fluid in reservoir. |
| Action- |
| Fill reservoir to within 1/2'
of full with platform on ground with factory recommended Pennzoil
Arctic hydraulic fluid, Dextron II if not available. (Power
down models fill to 1/2' of full with platform raised).
|
| (Diagnosis time -10 minutes / Repair time - 10 minutes). |
|
| Part Numbers - |
N/A |
| Possible Cause #2 |
Cylinder
piston seal blown allowing fluid to leak past piston when
trying to raise platform. |
| Action- |
|
ATU-25100 (AST-1500, AST-2000, ASTL-1800, ATU-1800)
|
| ATU-50100
(ASTL-2500, AST-2500, ATU-2500 Cylinder) |
| ATU-75100
(AST-3000, ATU-300, ATU-3500 Cylinder) |
| ATU-25113-WR
(ATU-25100 Seal kit) |
| ATU-50123-WR
(ATU-50100 Seal kit) |
| ATU-75112
(ATU-75100 Seal kit) |
|
| Possible Cause #3 |
Lowering
valve stuck partially or fully open. |
| Action - |
| With platform on ground, remove lowering
valve and inspect. Clean if dirty. Replace if plunger
not freely moveable. |
|
(Diagnosis time - 1/2 hr. / Repair time - 15 minutes). |
|
| Part Numbers - |
| ATU-121 (Monarch)
Lowering valve |
|
ATU-479 (Fenner) Lowering valve |
|
| Possible Cause #4 |
Incorrect
pressure setting on hydraulic pump. |
| Action- |
Loosen lock nut and turn allen screw clockwise to increase
pressure. Turn in all the way, then back out one full
turn, retighten lock nut, test liftgate with load. If
liftgate performs well, set pump pressure according to
factory settings. |
| Part Numbers - |
N/A |
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