Doosan D20S-5 Operation & Maintenance Manual page 135

12 Months Inspection 12 Months Inspection
Forks should be inspected, at a minimum, every 12 Forks should be inspected, at a minimum, every 12
months. If the truck is being used in a multi-shift or months. If the truck is being used in a multi-shift or
heavy duty operation, they should be checked heavy duty operation, they should be checked
every six months. See "Forks" in the "2000 Service every six months. See "Forks" in the "2000 Service
Hours or Yearly" in "Maintena Hours or Yearly" in
Maintenance and Repair Maintenance and Repair
1. 1. Repair forks only in accordance with the Repair forks only in accordance with the
manufacturer's recommendations. manufacturer's
Most repairs or modifications should be done Most repairs or modifications should be done
only by the original manufacturer of the forks or only by the original manufacturer of the forks or
an expert knowledgeable of the materials, an expert knowledgeable of the materials,
design, welding and heat treatment process. design, welding and heat treatment
2. 2. The following repairs or modifications SHOULD The following repairs or modifications SHOULD
NOT be attempted. NOT be attempted.
Flame cutting holes or cutouts in fork Flame cutting holes or cutouts in fork
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blades. blades.
Welding on brackets or new mounting Welding on brackets or new mounting
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hangers. hangers.
Repairing cracks or other damage by Repairing cracks or other damage by
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welding. welding.
Bending or resetting. Bending or resetting.
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3. 3. The following repairs MAY be
The following repairs MAY be performed.
Forks may be sanded or lightly ground, to Forks may be sanded or lightly ground, to
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remove rust, corrosion or minor defects remove rust, corrosion or minor defects
from the surfaces. from the surfaces.
Heel sections may be ground with a carbon Heel sections may be ground with a carbon
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stone to remove minor surface cracks or stone to remove minor surface cracks or
defects. Polish the inside radius of the heel defects. Polish the inside radius of the heel
section to increase the fatigue life of the section to increase the fatigue life of the
fork. Always grind or polish in the direction fork. Always grind or polish in the direction
of the blade and shank length. of the blade and shank length.
Repair or replace the positioning locks on Repair or replace the positioning locks on
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hook type forks. hook type forks.
Repair or replace most fork retention Repair or replace most fork retention
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devices used with other fork types. devices used with other fork types.
4. 4. A fork should be load tested before being A fork should be load tested before being
returned to service on completion of repairs returned to service on completion of repairs
authorized and done in accordance with the authorized and done in accordance with the
manufacturer's recommendations. manufacturer's
Most manufacturers and standards require the Most manufacturers and standards require the
repaired fork to be tested with a load 2.5 times repaired fork to be tested with a load 2.5 times
the specified capacity and at the load center the specified capacity and at the load center
marked on the fork arm. marked on the fork ar
"Maintenance Intervals." nce Intervals."
recommendations.
process.
performed.
recommendations.
m.
-132- -132-
With the fork restrained in the same manner as With the fork restrained in the same manner as
its mounting on the lift truck, apply the test load its mounting on the lift truck, apply the test load
twice, gradually and without shock. Maintain the twice, gradually and without shock. Maintain the
test for 30 seconds each time. test for 30 seconds each time.
Check the fork arm before and after the second Check the fork arm before and after the second
application of the test load. It shall not show any application of the test load. It shall not show any
permanent deformation. permanent deformation.
Consult Consult the the fork fork
information as may be applicable to the specific information as may be applicable to the specific
fork involved. fork involved.
Testing is not required for repairs to the positioning Testing is not required for repairs to the positioning
lock or the markings. lock or the markings.
Maintenance Section Maintenance Section
manufacturer manufacturer for for further further