Caterpillar 325
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 325 is a mid-size crawler excavator featuring a compact-radius design and powered by a Cat C4.4 engine producing 172 horsepower (129 kW). Operating weight ranges from 22,500 kg (49,604 lb) with 24-inch grouser shoes to 28,800 kg (63,493 lb) with 31-inch shoes. Production began in March 2020, succeeding the 325F model. Configurations include three cab options (Comfort, Deluxe, Premium), two counterweights (8.3-ton for lifting, 4.9-ton for transport), and various stick lengths. The machine is engineered for urban construction and confined spaces, offering maximum dig depth of 6.72 m (22 ft 1 in) and maximum loading height of 7.65 m (25 ft 1 in).
The 325 introduced a 25 percent reduction in fuel consumption compared to the 325F, alongside extended and synchronized maintenance intervals that reduce maintenance costs by up to 20 percent. It features Smartboom technology to reduce operator stress and fuel use, and Cat Advansys bucket tips for quick changes. The machine matters in the used and parts market because its consolidated filter locations and ground-level maintenance checkpoints lower service time. Its robust Cat C4.4 powertrain and advanced hydraulic system provide a reliable platform for specialized applications, including amphibious conversions for wetland and dredging projects.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar 325 specifications
Engine
| Model | Cat C4.4 |
| Gross Power | 122 kW (166 PS) |
| Net Power | 120 kW (163 hp) |
| Emissions Tier | U.S. EPA Tier 4 Final / EU Stage IV |
Weights
| Operating Weight (Standard) | 22,500 kg (49,604 lb) |
| Operating Weight (Long Undercarriage) | 28,800 kg (63,493 lb) |
| Transport Weight | 25,100 kg (55,336 lb) |
Dimensions
| Transport Length | 10.26 m (33 ft 8 in) |
| Transport Width | 3.0 m (9 ft 10 in) |
| Transport Height | 3.25 m (10 ft 8 in) |
| Track Shoe Width | 600 mm (24 in) |
| Tail Swing Radius | 2.9 m (9 ft 6 in) |
Performance
| Max Dig Depth | 6.7 m (22 ft) |
| Max Loading Height | 7.65 m (25 ft 1 in) |
| Max Travel Speed | 5.6 km/h |
| Gradeability | 70% |
Forces
| Bucket Digging Force | 180 kN (40,470 lbf) |
| Stick Digging Force | 130 kN (29,220 lbf) |
Service capacities (summary)
| Fuel Tank | 500 L (132 gal) |
| Hydraulic System | 230 L (61 gal) |
| Engine Oil | 12 L (3.2 gal) |
| Cooling System | 20 L (5.3 gal) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
325 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | 34 l (9 gal) | Cat DEO or TDTO; viscosity per ambient temperature chart in the operation and maintenance manual |
| Cooling system | 30 l (7.9 gal) | Cat ELC or extended-life coolant; conforming to Cat specification for ethylene glycol-based coolant |
| Fuel tank | 520 l (137.4 gal) | Ultra-low sulfur diesel (ULSD) meeting ASTM D975 or regional equivalent |
| Hydraulic system total AND hydraulic tank | 260 l (68.7 gal) total; 145 l (38 gal) hydraulic tank | Cat HYDO or equivalent high-zinc hydraulic oil; viscosity class per ambient temperature chart in the operation and maintenance manual |
| Final drive (each) | 8 l (2 gal) | Cat TDF or equivalent final drive fluid; viscosity per ambient temperature chart in the operation and maintenance manual |
| Swing drive | 10 l (2.6 gal) | Cat TDF or equivalent swing drive fluid; viscosity per ambient temperature chart in the operation and maintenance manual |
| Pilot/other circuits | Not documented for this exact serial range — verify with your dealer | Not documented for this exact serial range — verify with your dealer |
| Grease (spec only) | Not applicable | Lithium complex or polyurea-based grease conforming to NLGI Grade 2; resistance to water washout and corrosion |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 325 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the 325 beyond the schedule
Predictive Maintenance & Fluid Analysis
Integrate S.O.S fluid analysis into the 1,000-hour and 2,000-hour intervals to monitor engine oil, hydraulic fluid, and coolant for wear metals and contamination. The Cat C4.4 engine requires strict adherence to oil change intervals to prevent piston and bearing wear. Monitor hydraulic particle counts to protect the sophisticated hydraulic system from pump and valve damage. Check coolant pH and SCA concentration to prevent liner pitting and corrosion. Use the in-cab monitor to track filter life and maintenance intervals, ensuring timely intervention before component failure occurs.
Corrective & Common Repairs
Address hydraulic hose abrasion and leaks during daily inspections to prevent system contamination. Replace the air filter primary element at 1,000 hours, or more frequently in dusty conditions, to protect the Cat C4.4 engine from dirt ingestion. Inspect the turbocharger and fuel system for leaks that affect the 172 horsepower output. Check swing drive oil levels to prevent swing torque loss on slopes. Replace worn undercarriage components before they damage mating parts, as delayed measurement leads to costly full undercarriage rebuilds. Ensure all grease points on the boom, stick, and bucket are lubricated to prevent pin and bushing wear.
Overhaul & Rebuild Points
The 2,000-hour interval mandates a hydraulic oil change and coolant flush to prevent internal corrosion and overheating. Inspect final drive oil for gear wear metals during the 1,000-hour service. Evaluate major components and perform comprehensive structural inspections of boom and stick welds at 2,000 hours. Torque ROPS bolts to ensure cab integrity. Replace all worn belts and hoses during the 2,000-hour service. Monitor swing drive oil condition and replace as needed to maintain stability. Plan for engine rebuilds based on oil analysis results to avoid catastrophic failure.
Seasonal & Environment Servicing
In dusty or quarry environments, check the air filter daily and replace at 500 hours to prevent accelerated engine wear. Clean radiator and oil cooler fins daily to maintain cooling efficiency. In cold weather, ensure coolant concentration is adequate to prevent freezing and liner pitting. Check battery load and terminals regularly to ensure reliable starts. In wetland or amphibious applications, inspect the custom hydraulic propulsion system and buoyant pontoons for damage. Monitor ground pressure and track tension to prevent sinking in soft terrain. Adjust maintenance intervals based on operating conditions to extend equipment life.
325 fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| E360-3 | Engine Coolant Temperature — High (Critical) | Low coolant level, failed thermostat, water pump failure, or blocked radiator/cooler cores. | Stop operation immediately. Check coolant level and inspect for leaks. Do not restart until cooling system is verified. |
| E361-3 | Engine Coolant Temperature — Very High (Shutdown) | Severe cooling system failure or catastrophic loss of coolant. | Engine shutdown required. Perform full cooling system diagnosis before restart. |
| 110-0 | Engine Coolant Temperature — Above Normal | Low coolant level, thermostat failure, or restricted airflow. | Inspect cooling system, refill coolant, and test thermostat function. |
| 110-3 | Engine Coolant Temperature Sensor — Voltage High | Open circuit in sensor wiring or failed sensor. | Check wiring harness for damage; replace sensor if confirmed faulty. |
| 174-3 | Engine Fuel Temperature — Voltage Above Normal | Open circuit in fuel temperature sensor wiring. | Inspect harness and replace sensor if necessary. |
| 190-8 | Engine Speed — Abnormal Frequency | Speed sensor air gap issue, sensor failure, or tone ring damage. | Check sensor gap; test speed sensor and tone ring. |
| 41-3 | 8-Volt DC Supply — Voltage Above Normal | Short to power on 8V reference circuit. | Inspect sensors sharing the 8V supply and isolate the fault. |
| 41-4 | 8-Volt DC Supply — Voltage Below Normal | Short to ground on 8V reference circuit. | Disconnect sensors one at a time to locate the short. |
| 2348-9 | SAE J1939 Data Link #2 — Abnormal Update Rate | CAN bus wiring damage or termination fault. | Check CAN wiring and measure termination resistance. |
| 157-18 | Engine Injector Metering Rail #1 Pressure — Low | Fuel system pressure issue or sensor fault. | Verify fuel pressure and inspect injector rail sensors. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
325 attachments & work tools
Buckets
Factory specifications list a Heavy Duty (HD) bucket capacity of 1.19 m³ (1.56 yd³). Caterpillar offers general duty, heavy duty, extreme duty, and severe duty buckets, as well as specialized designs for ditch cleaning, rock, and finishing work. Bucket widths vary by configuration; aftermarket listings cite 48-inch (1219 mm) widths for this class.
Hydraulic hammers
The machine supports auxiliary hydraulic options for a wide range of attachments, including hydraulic hammers. The 325 class typically pairs with medium-to-large breaker classes; specific breaker weight classes are not defined in the source text and vary by configuration/series.
Quick couplers
Cat couplers for excavators enable fast, secure attachment changes without leaving the cab. Options include Pin Grabbers and hydraulic quick connect types. Aftermarket listings confirm compatibility with 80 mm and 90 mm pin configurations for this machine class.
Thumbs/grapples
The machine is compatible with bucket thumbs and rotating grapple attachments. Factory options include heavy-duty sticks and bucket thumbs to enhance balance and control. Aftermarket manufacturers produce concrete grapples, bypass grapples, and rotating log grapples specifically for the Caterpillar 325.
Rippers
The 325 excavator supports ripper attachments for heavy-duty applications. Aftermarket catalogs list single-tooth rippers and root rakes as compatible options for this machine class.
Hydraulic-kit notes
The main system maximum flow is 429 L/min (113 gal/min). Maximum pressure for equipment is 5075 psi (35000 kPa), rising to 5510 psi (38000 kPa) in lift mode. Auxiliary hydraulic options are required to power attachments such as hammers, grapples, and thumbs.
All 325 assemblies by section
Every catalogued assembly group for the Caterpillar 325. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Telescopic Stick And Clamshell
Clamshell Bucket Assembly
Clamshell Bucket Cylinder Assembly
Clamshell Bucket Piping
Free Joint Assembly
Front Lubrication System
Hose Reel Assembly-Part 2 Of 3
Hose Reel Assembly-Part 3 Of 3
Hose Reel Assembly-Part 1 Of 3
Telescopic Cylinder-Part 1 Of 3
Telescopic Cylinder--Part 3 Of 3
Telescopic Cylinder-Part 2 Of 3
Telescopic Piping
Telescopic Stick Assembly
Frequently asked questions
What engine does the Caterpillar 325 use?
The Caterpillar 325 uses a Cat C4.4 engine producing 172 horsepower (129 kW).
What is the operating weight of the Caterpillar 325?
Operating weight varies by configuration: 22,500 kg (49,604 lb) with 24-inch grouser shoes and 28,800 kg (63,493 lb) with 31-inch shoes.
What model replaced the Caterpillar 325?
The Caterpillar 325 succeeded the 325F model, introduced in March 2020.
What 325 owners discuss
What are the known powertrain and hydraulic behaviors for the Caterpillar 325?
What undercarriage or wear patterns are typical for this machine type?
What are the engine quirks per series for the Caterpillar 325?
What are common electrical or sensor issues reported?
What should be checked when buying a used Caterpillar 325?
What are the fluid specifications for the Caterpillar 325?
What safety-critical fixes require dealer verification?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific 325 part?
Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.