Service Training
MALAGA
TRACK TYPE LOADERS
Francis
July 1997
2 Page:
TRACK-TYPE LOADERS
HYDROSTATIC DRIVE SYSTEM
AUDIENCE
Level II – Service personnel who understand the principles of machine systems operation, diagnostic equipment, and procedures for testing and adjusting.
CONTENT
The information contained within this package deals with the 943 through the 973 Track-type Loaders. Changes have occurred since the release of STMG 493 plus the addition of the 953B model warrant this STMG on the hydrostatic transmission.
OBJECTIVES
After learning the information in this presentation, the serviceman will be able to: 1. locate and identify all major transmission components;
2. identify pressure tap locations and explain the purpose of each pressure test;
3. trace the flow of oil through the drive system during the different system conditions; and 4. explain the operation of each component in the transmission systems.
REFERENCES
953B Track-type Loader Service Manual SENR5270
963 Track-type Loader Service Manual SENR2280
973 Track-type Loader Service Manual SENR2454
953B Track-type Loader Parts Book SEBP2170
963 Track-type Loader Parts Book HEBP1366
973 Track-type Loader Parts Book HEBP1386
953B Track-type Loader (Advertising Literature) AEHQ3606
PREREQUISITES
STMG 493 "Hydrostatic Drive System for Track Loaders" SESV1493
CHAPTER : Introduction
3 Page:
SUPPLEMENTARY TRAINING MATERIAL
Service Magazine "Troubleshooting, Service Tips, And Major Improvements For
Hydrostatic Transmissions" December 5, 1984 SEBD1487
Service Magazine Article "Service Replacement Parts for Replenishing Valve on Hydrostatic
Transmission" May 3, 1993 SEPD0152
Service Magazine Article "Improved Filtration of Hydrostatic Transmission Filters"
January 20, 1992 SEPD0097
Schematic - 953B Track-type Loader Power Train SENR5276
Schematic - 943, 953, 963 Track-type Loader Power Train SENR3034
Schematic - 973 Track-type Loader Power Train SENR3079
Video Tape "Hydrostatic Loader Troubleshooting I - Learning The Seven Systems" SEVN9185 Video Tape "Hydrostatic Loader Troubleshooting II - Analyzing The Data Sheet" SEVN9186
Slide Presentation - 1.1 Liter Engine Family LESV0556
Video Tapes - 3100 Series Engines (11 tape set) LEKV8596
CHAPTER : Introduction
4 Page:
POWER TRAIN COMPONENTS
CHAPTER : HYDROSTATIC DRIVE SYSTEM
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
VARIABLE DISPLACEMENT PUMP HYDRAULIC LINES FIXED DISPLACEMENT MOTOR
BASIC DRIVE SYSTEM
5
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
CHARGE PUMP CHARGE RELIEF VALVE COOLER VARIABLE DISPLACEMENT PUMP FIXED DISPLACEMENT MOTOR
BASIC DRIVE SYSTEM
WITH CHARGE CIRCUIT AND COOLER
CHARGE AND MAIN RELIEF
VALVE
MAIN RELIEF VALVE
6
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
UNDERSPEED VALVE OPERATOR INPUT ENGINE SPEED SERVO VALVE CHARGE PUMP CHARGE RELIEF VALVE COOLER VARIABLE DISPLACEMENT PUMP FIXED DISPLACEMENT MOTOR
BASIC DRIVE SYSTEM
WITH UNDERSPEED AND SERVO VALVES
MAIN RELIEF VALVE
CHARGE AND MAIN RELIEF
VALVE
7
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
UNDERSPEED VALVE OPERATOR INPUT ENGINE SPEED SERVO VALVE CHARGE PUMP CHARGE RELIEF VALVE COOLER VARIABLE DISPLACEMENT PUMP FIXED DISPLACEMENT MOTOR
BASIC DRIVE SYSTEM BOTH DRIVE LOOPS
MAIN RELIEF VALVE
SERVO VALVE VARIABLE DISPLACEMENT PUMP FIXED DISPLACEMENT MOTOR CHARGE AND MAIN RELIEF VALVE MAIN RELIEF VALVE CHARGE AND MAIN RELIEF VALVE 8 Page:
9 Page:
ROTATING GRTOUP
CHAPTER : HYDROSTATIC DRIVE SYSTEM
10 Page:
PUMP GROPUP
CHAPTER : HYDROSTATIC DRIVE SYSTEM
11 Page:
HYDROSTATIC TRANSMISSION
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
PARK FILTER FILTER RELIEF VALVE CHARGE PUMP SCREEN VENTURI UNDERSPEED CUT-IN SCREW START/VENT SPOOL DIRECT QUICK RESPONSE VALVE
VENTURI THROAT ORIFICE
CHARGE PUMP AND FILTER SYSTEM
MAXIMUM REVERSE MAXIMUM FORWARD 12 Page:
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
BRAKES OFF FORWARD REVERSE BRAKES OFF
PARK FILTER FILTER RELIEF VALVE CHARGE PUMP SCREEN VENTURI UNDERSPEED CUT-IN SCREW PILOT VALVE START/VENT SPOOL CHARGE PRESSURE CHECK VALVE SPEED/BRAKE SPOOL SERVO RELIEF VALVE UNDERSPEED OVERRIDE VALVE UNDERSPEED VALVE DIRECTION/ SPEED LINK OVERSPEED VALVE QUICK RESPONSE VALVE VENTURI THROAT ORIFICE
UNDERSPEED AND OVERSPEED SYSTEM
MAXIMUM REVERSE MAXIMUM FORWARD TO BRAKES 13 Page:
14 Page:
UNDERSPEED VALVE
CHAPTER : HYDROSTATIC DRIVE SYSTEM
15 Page:
UNDERSPEED VALVE
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
16 Page:
UNDERSPEED VALVE
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
17 Page:
SPEED/DIRECTION CONTROL LEVER
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
18 Page:
UNDERSPEED VALVE
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
19 Page:
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
SPEED/DIRECTION CONTROL LEVER
20 Page:
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
UNDERSPEED VALVE
CHAPTER : HYDROST
A
TIC DRIVE SYSTEM
TRACK TYPE LOADERS
BRAKES OFF FORWARD REVERSE BRAKES OFF
BRAKES ON PARK FILTER FILTER RELIEF VALVE CHARGE PUMP SCREEN VENTURI UNDERSPEED CUT-IN SCREW PILOT VALVE ORIFICE TO PILOT VALVE OPERATE/BRAKE SPOOL START/VENT SPOOL CHARGE PRESSURE CHECK VALVE SPEED/BRAKE SPOOL QUICK RESPONSE VALVE VENTURI THROAT ORIFICE
OPERATE/BRAKE SPOOL SYSTEM
MAXIMUM REVERSE MAXIMUM FORWARD TO BRAKES 21 Page:
22 Page:
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
LEFT SERVO CYLINDER RIGHT SERVO CYLINDER
LEFT DRIVE PUMP LEFT DRIVE PUMP
LUBE SCREEN
RIGHT DRIVE PUMP RIGHT DRIVE PUMP LUBE SCREEN SERVO RELIEF
VALVE
SERVO CONTROL SYSTEM
NEUTRAL SCREW
SERVO VALVE
SERVO VALVE CENTERING LINK
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
TO BRAKES
LEFT TRACK
MOTOR RIGHT TRACK MOTOR
COOLER
RIGHT CHARGE AND MAIN RELIEF VALVE
LEFT CHARGE AND MAIN RELIEF VALVE
SHUTTLE SPOOL SHUTTLE SPOOL TOWING PLUG TOWING PLUG MAIN RELIEF VALVE MAIN RELIEF VALVE SYNC VALVE SYNC CUTOFF VALVE CHARGE PRESSURE RELIEF VALVE
COOLER BYPASS VALVE
LEFT SERVO CYLINDER
RIGHT SERVO CYLINDER
LEFT
DRIVE PUMP
LEFT DRIVE PUMP LUBE SCREEN
RIGHT
DRIVE PUMP
RIGHT
DRIVE PUMP LUBE SCREEN
OIL COOLER
RETURN SCREEN
PISTON PUMPS, MOTORS AND RELIEF SYSTEM
NEUTRAL SCREW
SERVO VALVE SERVO VALVE
CENTERING LINK
SYNC SCREW
23 Page:
24 Page:
SERVO VALVE
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
25 Page:
CHAPTER : HYDROSTATIC DRIVE SYSTEM
TRACK TYPE LOADERS
LEFT TRACK MOTOR RIGHT TRACK MOTOR COOLER SHUTTLE SPOOL SHUTTLE SPOOL TOWING PLUG TOWING PLUG SYNC VALVE SYNC CUTOFF VALVE CHARGE PRESSURE RELIEF VALVE COOLER BYPASS VALVE OIL COOLER RETURN SCREEN
