CARRIER 3S8057 - Caterpillar

Illustration 1 g03321603
The front drum and the rear drum on the machines are hydrostatically driven. The drive system consists of the following components:
A single variable displacement piston type pump
A two speed radial piston motor on each drum
A spring applied, hydraulically released brake on each drumThe charge pump supplies charge oil to the propel system.
Illustration 2 g03321605
Solid Drum Propel Control System (1) Machine ECM number "two" (2) Keypad (3) Machine ECM number "one" (4) Parking brake switch (5) Display (6) Engine ECM (7) Front back-up alarm (8) Rear back-up alarm (9) 360? reverse relay (10) Propel lever (11) Seat position switch "1" (12) Seat position switch "2" (13) Diagnostic connector (14) Interlock solenoid (15) Propel reverse solenoid "1" (16) Propel forward solenoid "1" (17) Shift solenoid (18) Right front speed sensor (19) Left rear speed sensorNote: The blue lines in the above illustration indicate an input signal. The red lines indicate an output signal. The red and blue lines indicate two-way communications.Machine ECM number "one" (3) monitors input signals from the following components in order to control the propel system:
Machine ECM number two (1)
Keypad (2)
Parking brake switch (4)
Engine ECM (6)
Propel lever (10)
Seat position switch "1" (11)
Seat position switch "2" (12)
Right front speed sensor (18) Display (5) monitors input signals from left rear speed sensor (19). This information is relayed to machine ECM number "one" (6) through the CAN lines.If the speed range is set to high, machine ECM number "one" (3) energizes shift solenoid (17) .Machine ECM number "one" (3) monitors seat position switch "1" (11) and seat position switch "2" (12) in order to determine which direction the operator station is facing. At the same time, the ECM monitors the position of propel lever (10). The machine ECM number "two" transmits a control signal to the 360? reverse relay (9) based on input from machine ECM number "one" on position of the operator station. Engine ECM (6) transmits power to the 360? reverse relay based on the position of the propel lever. If the propel lever is operating in the reverse range, the engine ECM energizes front back-up alarm (7) or rear back-up alarm (8) respectively.Machine ECM number "one" (3) transmits information used by display (5) in order to provide information to the operator about the propel system during operation.The propel system section of this presentation is divided into segments. The first segments show the location of all electrical and hydraulic components on the machine which are part of the propel system. A brief discussion of each component is provided in these segments. The last two sections explain the operation of the electrical and hydraulic systems. Schematics are used in this segment to trace current through the electrical system and hydraulic oil through the hydraulic system.