CABLE AS 2991660 - Caterpillar

Do not exceed the air pressure of 830 35 kPa (120 5 psi) or damage can occur to the air system components.
Connect the steering system to 1U-5000 Auxiliary Power Supply. Refer to Special Instruction, SEHS8715 and Special Instruction, SEHS8880.
Personal injury or death could result when towing a disabled machine incorrectly.Block the machine to prevent movement before releasing the brakes. The machine can roll free if it is not blocked.
Reference: See Operation And Maintenance Manual, "Towing The Machine" for more towing information.Reference: See Testing And Adjusting, "Towing The Machine - Preparation" for the towing procedure.Place the air control valve for the parking brake to the OFF position. Air will enter the parking and secondary brake valve which will cause the control spool to move. This will prevent oil from returning to the hydraulic tank when the electric drive pump that releases the parking brake and the secondary brake is operating. The electric drive pump that releases the parking brake and the secondary brake will be used to supply oil in order to release the parking and secondary brakes. The electric drive pump that releases the parking brake and the secondary brake is operated by a switch that is located in the cab. The hydraulic oil will flow from the pump through the parking and secondary brake valve to the brakes. The oil will be used to release the spring applied parking brakes.
Illustration 1 g00506064
Towing schematic (1) Relief valve (2) Air flow to the parking and secondary brake valve (3) Oil flow to the torque converter and front brake cooling diverter valve (4) Pilot oil for the hoist control valve (5) Parking and secondary brake valve (6) Return oil flow back to the hoist, torque converter, and brake section of the hydraulic tank (7) Oil flow to the torque converter lockup clutch (8) Check valve (9) Traction control valve (10) Front brake (11) Rear brake (12) Electric drive pump that releases the parking and the secondary brake (13) Electric motor (14) Electrical leads to the switch in the cab (15) Parking brake release hydraulic filter (16) Parking brake release pump section (17) Suction screen (18) Hoist, torque converter, and brake section of the hydraulic tank (19) Oil chamber for the parking brakes (all four brakes)Note: Arrows show oil flow.
Illustration 2 g00337252
(12) Electric drive pump that releases the parking and the secondary brake (13) Electric motor
Illustration 3 g00916013
Location of the air control valve for the parking brake
Illustration 4 g00672723
Location of the switch for the electric drive pump that releases the parking and the secondary brake