SHIM 3162670 - Caterpillar

Illustration 1 g06194768
Oil makeup operation
(1) Motor rotary group
(2) Left travel motor
(3) Passage
(4) Check valve
(5) Swivel
(6) Pump 2
(7) Hydraulic tank
(8) Line
(9) Passage
(10) Left travel control valveTo prevent cavitation in the travel motors during a travel stop, makeup oil is supplied to the travel motors.The following description is given for a forward travel stop of the left travel motor. The right travel motor functions in the same manner as the left travel motor.During a travel stop, the travel levers/pedals are released and move to the NEUTRAL position. Supply oil from pump 2 is blocked at passage (9) on left travel control valve (10) and cannot flow to left travel motor (2).Since no oil is supplied to the left travel motor, the motor will attempt to stop. However, because of the inertia of the machine, the travel motor will continue to rotate. This action causes a vacuum condition in passage (3) of the travel motor.When the travel control valve shifts to the NEUTRAL position, return oil is pulled from the hydraulic tank, into line (8), and into the left travel control valve. From there the oil flows through swivel (5), through check valve (4), into passage (3) to motor rotary group (1) as makeup oil. This makeup oil prevents cavitation in the travel motor during travel stop.Makeup oil is supplied for reverse travel in the same manner as forward travel.