938G Series II Wheel Loader and IT38G Series II Integrated Toolcarrier Braking System Vane Pump (Braking) Caterpillar


Vane Pump (Braking)
`
938G Series II Wheel Loader and IT38G Series II <BR>Integrated Toolcarrier Braking System [RENR6074]
BRAKING SYSTEM
PUMP GP
938G Series II Wheel Loader and IT38G Series II Integrated Toolcarrier Braking System Vane Pump (Braking)



Illustration 1g00278440

Cab has been removed for photographic clarity.

Location of Brake Pump

The brake pump is a vane type pump. The brake pump is fastened to the implement pump, which is also attached to the steering pump. The pumps are located under the cab.




Illustration 2g00275065

Brake Pump

(1) Pressure port (outlet). (2) Tank port (inlet).




Illustration 3g00456366

Schematic of the Brake Pump Section

(3) Rotor. (4) Cam ring. (5) Outlet. (6) Passage. (7) Inlet. (8) Inlet. (9) Outlet. (10) Vanes (12). Callouts (A) through (G) are the various locations of the vanes. (AA) Pressure oil. (BB) Supply oil.

The following items are the components of the brake pump section: a plate, adapter, seal packs, rotor (3), cam ring (4) and vanes (10). The brake pump does not have inserts inside the vanes.

First, vanes (10) are pushed against cam ring (4) by centrifugal force. Pressure oil in passages (6) of rotor (3) keeps the vanes pushed against the cam ring. Both ends of the vanes are connected by the passages. This oil maintains an even pressure on both ends of the vanes. This oil also permits the oil behind the vanes to escape as the vanes are pushed in.

As rotor (3) turns, the vanes in locations (F) and (G) move outward. The vanes follow the shape of cam ring (4). As the chamber area between the vanes increases, a low pressure or a low vacuum is created in the chamber. This pressure difference causes oil to flow from the hydraulic oil tank through inlet (8). The oil fills the space between the vanes at locations (F) and (G). The oil continues to fill the space through locations (E) and (A) .

Oil between the vanes at locations (E) and (A) will be trapped when the vane at location (E) passes the end of inlet (8). As rotor (3) continues to turn, the vanes are pushed inward by the contour of cam ring (4). The chamber area between the vanes now decreases. The oil between the vanes at locations (A) and (B) is pushed into outlet (5) .

The oil continues to be pushed through locations (C) and (D). When the vane at location (C) passes the end of outlet (5), the cycle is completed.

Reference: For additional information about the hydraulic system, refer to Systems Operation and Testing and Adjusting, RENR6077, "938G II Wheel Loader and IT38G II Integrated Toolcarrier Hydraulic System".

Reference: For additional information about this type of vane pump, refer to Special Instruction, SMHS7047.

Information System:

3524B Engine for Caterpillar Built Machines Flywheel - Remove and Install
3054E Industrial Engine Fuel System Pressure - Test
938G Series II Wheel Loader and IT38G Series II Integrated Toolcarrier Braking System General Information (Braking)
3516B and 3516C Engines for Off-Highway Trucks Lubrication System
14H Motor Grader Machine Systems Gerotor Motor (Circle Drive) - Remove
Product Link 151/201 Reports and Messages Not Available
Product Link 151/201 Electronic Service Tool Does Not Communicate with ECM
RM-350B Road Reclaimer/Soil Stabilizer Machine Systems Rotor Drive Differential - Disassemble
Product Link 151/201 Diagnostic Capabilities
Product Link 151/201 Service Tools
IT38G Series II Integrated Toolcarrier and 938G Series II Wheel Loader Machine Preparation for Troubleshooting
AP-1000D, AP-1055D, AP-655C, BG-2255C, BG-2455D and BG-260D Asphalt Pavers MID 030 - CID 0096 - FMI 03
AP-1000D, AP-1055D, AP-655C, BG-2255C, BG-2455D and BG-260D Asphalt Pavers MID 030 - CID 0248 - FMI 02
R2900 Load Haul Dump Service Inspection
IT38G Series II Integrated Toolcarrier and 938G Series II Wheel Loader Hydraulic System
938G Series II Wheel Loader and IT38G Series II Integrated Toolcarrier Braking System Accumulator Charging Valve (Brake)
D5N Track-Type Tractor Seat
TK711, TK721, TK722 and TK732 Track Feller Bunchers Hydraulic System Machine Preparation for Troubleshooting
14H Motor Grader Machine Systems Centershift Lock - Remove
14H Motor Grader Machine Systems Centershift Lock - Install
AP-1000D, AP-1055D, AP-655C, BG-2255C, BG-2455D and BG-260D Asphalt Pavers MID 030 - CID 0263 - FMI 03
AP-1000D, AP-1055D, AP-655C, BG-2255C, BG-2455D and BG-260D Asphalt Pavers MID 030 - CID 0263 - FMI 04
R2900 Load Haul Dump Autoshift Control (STIC Steering)
R2900 Load Haul Dump Autoshift Control (Wheel Steering)