Description

Caterpillar 320C, 320B Technical Manual – Factory Specs for Hydraulic Excavators

If you’re running a 320C or a 320B in your fleet or your own dirt work, you’ve probably chased down a spec that a parts guy got wrong, or found three different numbers online for hydraulic pump flow. That’s the kind of frustration that costs you a half-day and a pissed-off operator. This Caterpillar 320C, 320B Technical Manual is the factory bulletin that Cat gave its dealer sales personnel to sell these machines—which means the numbers are locked to what Cat stamped on the build sheet. No aftermarket translation, no third-party interpretation. 40 pages of straight OEM data.

Engine Horsepower and Hydraulic Pump Flow – Factory Numbers

Page 7 gives you the net horsepower figures for both the 320C and 320B. The 320C runs a Cat 3066T engine with a net power of 138 hp (103 kW) at 1800 rpm. The 320B uses the 3116T engine, rated at 128 hp (95 kW). Those are the numbers you need when you’re setting a pump curve or arguing with a rental customer. Down on page 8, hydraulic pump flow is laid out: the 320C’s two variable-displacement piston pumps deliver 61.3 gpm each at 4,560 psi. The 320B’s pumps flow 56.5 gpm each. That difference matters when you’re sizing a hydraulic hammer or a tiltrotator. Page 9 covers front implement speed—boom raise, arm curl, bucket dump—all timed. These aren’t guesses; they’re Cat’s production test averages.

Swing Performance and Acceleration: What the Data Tells You

Swing speed, swing acceleration, and swing slope capability are broken out on pages 10, 11, and 12. The 320C has a swing speed of 11.5 rpm versus 11.0 rpm for the 320B. Swing acceleration from zero to full speed? The 320C hits it in 0.4 seconds faster. That might not sound like much until you are loading trucks on a 90-second cycle all day. Swing slope—the grade they can swing on without binding the swing gear—is 8 degrees for both machines. Page 12 gives the test method so you can verify it on your own machine if you want. This is the kind of detail that aftermarket summaries skip.

Productivity: Trenching and Level Truck Loading Benchmarks

Pages 14 through 17 are pure productivity data. Trenching productivity (page 15) shows the 320C moving 495 bank cubic yards per hour in a 24-inch trench at 15 feet depth, versus 438 for the 320B. Level truck loading productivity (page 17) gives cycle counts and tons per hour for each machine with a 2.5-yard bucket. If you are comparing used machines to bid a job, these pages are gold. The manual explains the test conditions—soil type, swing angle, haul distance—so you can adjust for your site. That’s why factory documentation is worth the money. You get the actual test protocol, not a marketing claim.

Versatility: Stackable Valves and Optional Tool Control System

Pages 18 and 19 cover the stackable valve arrangement and the optional tool control system. The 320C can accept up to four stackable sections for attachments like thumbs, shears, and multi-processors. The tool control system allows you to set flow and pressure ratios from the cab. If you’re adding a hydraulic attachment, you need to know which valve bank is available and what the pilot pressure taps are. These two pages explain the system architecture. For a complete breakdown of the electrical diagnostics and tool control module, the Caterpillar 312C 315C 320C 322C 325C Technical Training manual will get you deeper into the control logic.

Serviceability: Extended Intervals and Access Points

The serviceability section (pages 23–26) covers extended service intervals—oil change at 500 hours instead of 250 on the 320C, hydraulic filter change at 2000 hours compared to 1000 on the 320B. Page 25 talks about the oil cooler core design and how to backflush it. Page 26 hits the track adjustment procedure and the grease-point locations. The manual also lists track sag specs: 0.6 to 0.8 inches on the 320C under standard tension. That is the kind of number you need to prevent track walk in tight quarters. For a full step-by-step rebuild of the final drives, get the Caterpillar 320C 320C L 2004 Service Manual or the Caterpillar 320C 2001 Service Manual from our collection.

Keep in mind, this is a comparative bulletin—it does not include parts diagrams, torque specs, or wiring schematics. It is the spec sheet that Cat salesmen carried. That makes it ideal for verifying machine performance, not for rebuilding an engine. If you need to pull the head on a 3066T, use the proper service manual. (If you are working on a machine with a conventional Manual Transmission drivetrain, our external resources can help you with shift-linkage adjustments and clutch-pack specs.) Or if you are dealing with a wheeled excavator that has a separate Manual Transmission for travel, those specs are outside this document’s scope.

Who Should Buy This 40-Page Document

This is for equipment owners, fleet managers, and independent mechanics who need to verify that a 320C or 320B is performing to factory benchmarks. If you are buying a used machine and want to run a performance test against Cat’s published numbers, you need this bulletin. It is also useful for estimator who wants cycle-time data for bid quotes. Beginners should note that this manual assumes familiarity with excavator operation; it does not teach you how to run a machine. But if you know the basics, the trenching and loading tables will make you a better evaluator. The 40 pages are concise and every one carries a spec you can’t get from a parts catalog.

Does this manual include torque specifications or wiring diagrams?

No. This is a comparative bulletin for dealer sales personnel. It does not contain torque values, wiring schematics, or step-by-step repair procedures. Those are in the separate service manuals linked above.

Can I use this to rebuild the hydraulic pump on my 320C?

You can use the hydraulic pump flow and pressure data (page 8) to set the pump after a rebuild, but the rebuild procedure itself is not here. You need the 320C service manual for disassembly, seal part numbers, and bench-test specs. The bulletin gives you the factory targets. The service manual gives you the steps to hit them.

If you are tired of chasing specs that change depending on which forum you read, get the data that came from Caterpillar’s engineering department. This Caterpillar 320C, 320B Technical Manual puts factory performance, productivity, and serviceability numbers in your hands. Access the Factory Manual from AutoRepairManuals and keep it on your tablet in the cab.