Usage:
M315 (7ML),
M318 (8AL, 6ES, 8SS),
M320 (6WL, 9PS) WHEEL EXCAVATORS
Problem:
Traveling down a grade with wheel excavators at low engine speed or when the travel pedal is not depressed completely can produce abnormally high oil temperatures in the travel motor circuit. Abnormally high oil temperatures in this circuit may damage the travel motor and cause seal failures in the transmission.
The high oil temperature is a result of inadequate oil flow through the travel motor make-up circuit and the main system circuit, which includes the oil cooler.
Solution:
Maintain a relatively high engine speed and depress the travel pedal completely to insure the hydraulic oil is circulated through the travel motor make-up circuit, main system circuit and the oil cooler.
Operator procedure to prevent hydraulic oil overheating, while traveling down a grade:
- * Always turn the AEC (Automatic Engine Speed Control) off when traveling
- * SECOND GEAR may be selected for grades less than 10%. The travel pedal must always be depressed completely. The automatic brake valve will maintain the speed of the machine.
- * CREEPER MODE in SECOND GEAR must be selected for grades greater than 10%. Again the travel pedal is always depressed completely.
- * Maintain a relatively high engine speed to insure adequate hydraulic oil circulation.
- * FIRST GEAR should be used when traveling downhill at the job site.
- * SECOND GEAR may be selected for grades less than 10%. The travel pedal must always be depressed completely. The automatic brake valve will maintain the speed of the machine.
The operator should always select the same gear speed traveling down the grade that would be used to travel up the grade.
NOTE: This information will be published in the next update of the Operator and Maintenance Manual for all M300 Wheel Excavators.
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