International Harvester Company 15D-2 Operator's Manual page 39

SCHEDULED MAINTENANCE
PROBABLE CAUSE
REMEDY
Jerky Motion in Downstroke
1. Dashpot plunger spring or cap broken
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2. Float control plunger spring broken • ••
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Noisy Operation
1.
Air in system • • • • •
2. Insufficient oil supply
Vent hydraulic system.
Check level of oil in oil tank and add oil if
necessary.
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D rain hydraulic system and clean strainer.
3. Pump bearings worn out
4. Pump and coupling worn out.
5. Partially blocked pump inlet
6. Pump squealing caused by:
A. Air in system. • • • •
B. Insufficient oil supply.
C. Partially blocked pump inlet
7. Chattering relief valve spring. • • •
8. Broken flow control plunger spring
9. Broken dashpot plunger spring or cap
Vent hydraulic system.
Check level of oil in oil tank and add oil if-
necessary.
Drain hydraulic system and clean strainer.
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Load Slowly Drops (Valve Plunger in Hold Position)
1. Oil Ie aking by val ve plung e r , • • • •
2. Oil by-passing from holding s ide to
opposite side of piston ••••
3. Oil leaks at fittings or in cylinder
connecting line s • • • • • • •
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Check hydraulic system.
Momentary Drop of Load When Valve Plunger is Actuated From Hold to Raise or Raise to Hold
1. Scored or worn check valve plunger or
seat .......•.•.......
2. Check valve plunger held off its seat ••
3. Broken check valve spring. •• • •••
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Clean system. Check for foreign matter.
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Sticking Valve Plunger
1. Scored or burred lands in plunger bore •••
2. Mounting face not level, thereby distorting
hous ing • • • • • • • • • • • • •
3. Mounting bolts too tight or improperly
tightened .•....••..•..
4. Detent poppets worn or damaged (positive
position type only). • •
5. Dirt or foreign matter • •
6. Warped valve plunger
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Loosen and retighten to proper torque (50 lbs).
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Consult your authorized International Construction Equipment distributor or dealer.
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