| 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 ATF 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- |
| Remove breather hose from end of cylinder.
Activate power unit to raise positon, if hydraulic
fluid pumps out of breather port, repack or replace
cylinder. (If under warranty, replace cylinder DO
NOT repack or dismantle. |
| (Diagnosis
time- 10 minutes / Repair time - 1/2 hour). |
|
| Part Numbers - |
| ATU-25100 (AST-1500, ASTL-1800, AST-2000, ATU-1800) |
| ATU-50100 (ASTL-2500, AST-2500, ATU-2500
CYLINDER) |
| ATU-75100 (AST-3000, ATU-3000, 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 hour / 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.
Set pressure to factory specifications. |
|
|
| Part Numbers - |
N/A |
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