Komatsu H75051 Operation & Maintenance Manual page 276

MACHINE OPERATIONS AND CONTROLS
Deflection ratio = (H - h)/Hx100
As a guideline that can be checked visibly, the deflection ratio
of the front tire (deflection/free height) is as follows.
When carrying normal load (boom horizontal): Approximately
15 to 25 %
When digging (rear wheels off ground): Approximately 25 to
35 %
In addition to the checking of tire inflation pressure, check for
small cuts and peeling on tires, for sticking of nails and metallic
pieces that may cause punctures, and for any abnormal wear.
Keep the working road surface constantly clean by removing fallen stones. This will extend the tire life and give
improved economy.
• For operations on normal road surfaces, rock digging operations: High end of range in the following table.
• Stock pile operations on soft ground: Average pressure in air pressure chart
• Operations on sand (operations not using much digging force): Low end of range in the following table
If the deflection of the tire is excessive, raise the inflation pressure within the limits given in the following table to
give a appropriate deflection (see deflection ratio).
Tire size
(Pattern)
20.5-R25☆
(L3: Rock)
20.5-25-12PR
(L2:Traction)
Stock pile operation means scooping and piling gravel.
PRECAUTIONS FOR LOAD-AND-CARRY OPERATION
When traveling continuously in load-and-carry operation, choose the appropriate tires to match the operating
conditions, or choose the operating conditions to match the tires. If this is not done, the tires will be damaged.
Consult your Komatsu distributor or tire dealer.
3-210
H: Free
height
Ground (sandy
( mm)
ground)
Front
wheel
383
(ML)
Rear
wheel
Front
wheel
190 to 330
386
(BS)
{1.9 to 3.3}
Rear
wheel
Air pressure [ kPa { kg/cm
Stock pile
350 350
{3.5} {3.5}
190 to 330
{1.9 to 3.3}
2
}]
Normal road
Digging
350
{3.5}
210 to 350
{2.1 to 3.5}
OPERATION
When shipped
from the plant
350
{3.5}
350
{3.5}
325
{3.25}
280
{2.8}