Service Training SERV7103-04
New Product Introduction April 2003
Volume 4, Number 1
TECHNICAL PRESENTATION
320C/322C TIER II
HYDRAULIC EXCAVATORS
New Product Introduction
(NPI)
320C/322C TIER II HYDRAULIC
EXCAVATORS
CONTENT
This self paced, self directed presentation provides new and different New Product Introduction
(NPI) information for the 320C and 322C Tier II Emissions Hydraulic Excavators.
OBJECTIVES
After learning the information in this presentation, the technician will be able to:
1. locate and identify the new components on the Tier II Emissions Excavators; and
2. trace the oil flow through the fan system
REFERENCES
320C/322C Hydraulic Excavator Hydraulic Systems SERV2702
"300C" Series Hydraulic Excavator Electronic Control Systems SERV2693
320C Operation and Maintenance Manual SEBU7342
322C Operation and Maintenance Manual SEBU7433
320C Hydraulic System Operations RENR3816
322C Hydraulic System Operations RENR7149
320C Parts Manual SEBP3593
322C Parts Manual SEBP3677
320C Hydraulic System Testing and Adjusting Manual RENR3817
322C Hydraulic System Testing and Adjusting Manual RENR7150
Estimated Time: 30 Minutes
Visuals: 11
Form: SERV7103-04
Date: 04/03
© 2003 Caterpillar Inc.
SERV7103-04 -3- NPI
Vol. 4, No. 1, 2003
TABLE OF CONTENTS
INTRODUCTION ........................................................................................................................5
MACHINE APPEARANCE
No Changes
OPERATOR'S STATION
No Changes
ENGINE........................................................................................................................................8
COOLING SYSTEM..................................................................................................................10
Fan System............................................................................................................................12
HYDRAULIC SYSTEM
No Changes
UNDERCARRIAGE
No Changes
SIGNIFICANT MAINTENANCE CHANGES
No Changes
NEW TOOLING/SKILLS REQUIRED FOR SERVICE
No Changes
CONCLUSION...........................................................................................................................16
HYDRAULIC SCHEMATIC COLOR CODES.........................................................................17
NOTE: Refer to the Reference Materials for information on systems that have no
significant changes.
SERV7103-04 -4- NPI
Vol. 4, No. 1, 2003
NOTES
SERV7103-04 -5- NPI
Vol. 4, No. 1, 2003
320C/322C TIER II
HYDRAULIC EXCAVATORS
© 2003 Caterpillar Inc.
INTRODUCTION
The 320C and 322C have been updated to meet U.S. Environmental Protection Agency (EPA)
Tier II Emissions Regulations for North America and Stage II European Emissions Regulations.
The 320C and 322C Tier II Excavators are direct replacements for the 320C and 322C Tier I
Excavators.
SERV7103-04 -6- NPI
Vol. 4, No. 1, 2003
SIMILARITIES AND DIFFERENCES
FEATURES DIFFERENT SIMILAR SAME
Machine Appearance X
Operator's Station X
Engine X
Cooling System X
Hydraulic System X
Undercarriage X
Maintenance Items X
The 320C and 322C Tier II Excavators are very similar to their Tier I counterparts.
The 320C and 322C are equipped with a side-by-side cooling system, similar to the larger
"C" Series models.
The 322C contains a 3126B Engine equipped with a HEUI™ fuel system, similar to the 325C
Excavator. The 320C continues to use the 3066 Engine; however, it has been updated to meet
Tier II emissions.
SERV7103-04 -7- NPI
Vol. 4, No. 1, 2003
SPECIFICATIONS
320C and 322C
FEATURE 320C TIER II 322C TIER I 322C TIER II
Operating Weight 21000 kg (46,300 lb) 23100 kg (50,927 lb) 23200 kg (51,147 lb)
Engine 3066 3126 3126B
Net Power 103 kw (138 hp) 123 kW (165 hp) 125 kW (168 hp)
Fuel Capacity 400 L (106 gal) 400 L (106 gal) 500 L (132 gal)
This illustration shows the specifications for the 320C Tier II Excavator, 322C Tier I Excavator,
and the 322C Tier II Excavator.
The 320C Tier II Excavator specifications have not changed from the 320C Tier I Excavator.
SERV7103-04 -8- NPI
Vol. 4, No. 1, 2003
ENGINE
The 322C is equipped with a 3126B Engine (1) rated at 125 kW (168 hp). The engine is
controlled by the engine ECM (2). The engine is similar to a 325C Excavator engine. The flash
file is new for the 322C; it provides the engine with the operating characteristics of a 322C,
while maintaining Tier II emissions levels.
The 320C continues to use the 3066 rated at 103 kW (138 hp). The engine is Tier II compliant
by changing numerous internal and external components. Some changes are minor, such as
changing from lock washers to lock nuts on the exhaust manifold. Other changes are significant.
Some examples include:
- smaller dish on the top of the pistons
- new intake valves with heavy duty seats
- different tip and nozzle on the fuel injectors
- larger intake manifold and muffler
- single serpentine belt and pulleys
- different plunger and camshaft in the fuel injection pump
SERV7103-04 -9- NPI
Vol. 4, No. 1, 2003
The following is a list of engine components that are common between the Tier I and Tier II
320C machines:
- starter
- camshaft
- oil pan, oil pickup lines, engine oil cooler, and turbo oil lines
- flywheel and flywheel housing
- engine breather
- alternator mounting brackets
SERV7103-04 - 10 - NPI
Vol. 4, No. 1, 2003
4
3
COOLING SYSTEM
The 320C Tier II Excavator uses a side-by-side cooling group located on the left side of the
machine. The radiator (1) and hydraulic oil cooler (2) are mounted next to each other. The fixed
aftercooler (3) and air conditioning condenser (4) are mounted on the outside of the radiator
assembly. The condenser swings out for easy cleaning and service.
The 320C Tier II Excavator uses one belt-driven, suction-type fan to draw air through the
cooling system.
SERV7103-04 - 11 - NPI
Vol. 4, No. 1, 2003
3 1
4
2
The 322C Tier II cooling system is similar to the 325C Excavator cooling system. The 322C has
the radiator (1) and the aftercooler (2) mounted in the rear compartment. They are cooled by the
belt-driven, suction-type fan.
The hydraulic oil cooler (3) and air conditioning condenser (4) are in the front compartment, and
are cooled by a hydraulically driven fan.
NOTE: The radiator and aftercooler are normally separated from the hydraulic oil cooler
and air conditioning condenser by a firewall. Because this illustration shows a machine
during the assembly phase, the firewall has not been installed yet.
SERV7103-04 - 12 - NPI
Vol. 4, No. 1, 2003
Fan System
The fan pump (arrow) is a fixed-displacement, gear-type pump. The fan pump is driven by the
main hydraulic pumps.
SERV7103-04 - 13 - NPI
Vol. 4, No. 1, 2003
The fan motor (1) is a fixed-displacement, piston-type motor. The fan motor is coupled to the
fan (2), which draws air through the air conditioning condenser and the hydraulic oil cooler.
SERV7103-04 - 14 - NPI
Vol. 4, No. 1, 2003
The fan system relief valve group (2) is located in the pump compartment.
Fan system pressure can be checked at the pressure tap (1). Delivery pressure from the fan
pump is limited by the relief valve (3).
SERV7103-04 - 15 - NPI
Vol. 4, No. 1, 2003
322C TIER II FAN SYSTEM
ENGINE RUNNING
HYDRAULIC
OIL COOLER
FAN MOTOR
RELIEF FAN SYSTEM CASE DRAIN
VALVE PRESSURE TAP FILTER
FAN PUMP
MAKEUP VALVE
10
The fixed-displacement fan motor is rotated by flow from the fixed-displacement fan pump. Fan
speed is determined by engine speed.
Inertia keeps the fan rotating after the engine has been shut down. A makeup valve is provided
to prevent cavitation in the fan motor.
The relief valve limits the maximum system pressure for the fan. Fan system pressure can be
measured at the pressure tap on the relief valve.
SERV7103-04 - 16 - NPI
Vol. 4, No. 1, 2003
11
CONCLUSION
This presentation has provided New Product Introduction (NPI) information for the Caterpillar
320C Tier II and 322C Tier II Emissions Hydraulic Excavators. When used in conjunction with
the Service Manual, the information in this package should permit the technician to analyze
problems in any of the major systems on these hydraulic excavators.
SERV7103-04 - 17 - NPI
Vol. 4, No. 1, 2003
Hydraulic Schematic Color Code
Black - Mechanical connection. Seal Red - High pressure oil
Dark Gray - Cutaway section Red/White Stripes - 1st pressure reduction
Light Gray - Surface color Red Crosshatch - 2nd reduction in pressure
White - Atmosphere or Pink - 3rd reduction in pressure
Air (no pressure)
Purple - Pneumatic pressure Red/Pink Stripes - Secondary source oil pressure
Yellow - Moving or activated components Orange - Pilot, signal, or Torque Converter oil
Cat Yellow - (restricted usage) Orange/White Stripes -
Identification of components Reduced pilot, signal, or TC oil pressure
within a moving group
Orange Crosshatch - 2nd reduction in
Brown - Lubricating oil pilot, signal, or TC oil pressure.
Green - Tank, sump, or return oil Blue - Trapped oil
Green/White Stripes -
Scavenge Oil or Hydraulic Void
HYDRAULIC SCHEMATIC COLOR CODE
The colors on the hydraulic schematics and cross-sectional views shown throughout this
presentation denote specific meanings. This illustration identifies the meaning of each color.
