SERV1851 02/08
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Text Reference Travel System
TRAVEL CIRCUIT MAKEUP OPERATION
Travel Valve
Check Valve
180
When the travel valve is returned to NEUTRAL, the counterbalance valve also returns to NEUTRAL. When the counterbalance valve returns to NEUTRAL, the supply pressure to the motor drops as the motor continues to try to turn. Return oil to the travel control can be used as makeup oil to the low pressure side. Due to the back pressure created by the slow return check valve, the check valve in the counterbalance valve can unseat and allow return oil to enter the low pressure side of the motor. The crossover relief valve will also open to send oil in the high pressure side to the low pressure side of the travel motor to reduce motor cavitation.
