Description

Bobcat 320, 320L 2006 Service Manual

If you are turning wrenches on a Bobcat 320, 320L 2006 Service Manual is what you need on the bench. I have been an ASE Master Technician for 28 years and have seen what happens when guys rely on aftermarket PDFs with missing pages or wrong torque values. This 642-page factory document is the one Bobcat shipped to dealers. Skip it and you will be guessing on relief valve pressures or cylinder disassembly sequences. Guessing costs you time and parts.

Safety Instructions – Fire Prevention and Lifting Procedures

Page 1 gets straight to the point: “Never service the Bobcat Compact Excavator without instructions.” That is not a suggestion. The manual covers fire prevention, lifting and blocking the excavator, and proper use of the upperstructure slew lock. I have watched a guy try to service a hydraulic line with the machine on a slope and no blocks. That is how you lose fingers. The manual gives you the exact procedure for lifting and blocking – including the correct jack stands and cribbing. Do not skip this section.

Engine and Hydraulic System Maintenance Schedules

The service schedule chart is in the Safety and Maintenance section. It tells you when to change engine oil, replace the fuel filter, check the hydraulic filter, and service the alternator belt. There is a full fuel system subsection with fuel specifications, water removal from the fuel filter, and air bleed procedure. The engine lubrication system includes an oil chart and the right way to replace oil and filter. On the hydraulic side, you get diagnostic couplers and a step-by-step for replacing hydraulic oil. Every interval is based on hours of operation – not calendar date.

I have seen too many shop owners skip the travel motor oil level check. The manual covers that too, with a drain procedure. Same for the spark arrestor muffler and seat belt inspection. They even cover the control console lockout inspection. If you are a DIY guy working on your own excavator, this is the difference between a machine that lasts 10,000 hours and one that grenades at 3,000.

Hydraulic Control Valve Disassembly – 320 vs 320L Differences

The hydraulic system chapter is over half the book. Section titles include “Boom Cylinder – Testing, Removal and Installation, Parts Identification, Disassembly, Assembly” – and that pattern repeats for arm, boom swing, bucket, and blade cylinders. But the real meat is the hydraulic control valve disassembly. The manual has separate subsections for the 320 and the 320L. Each valve section – auxiliary, blade, slew, left travel, boom, bucket, arm, boom swing, right travel – gets its own disassembly and assembly procedure. If you mix up the 320 and 320L valve bodies you will have a machine that does not track straight. The manual shows the differences in parts identification and valve section layout.

Relief valve adjustments are covered too: main relief, port relief, crossport relief, and pressure reducing valve. Each one has a test and adjust procedure with specific pressures listed. I will not give you the numbers here because you need the book in front of you. But know that the manual tells you which port to tee into and what gauge range to use. Do not trust a third-party website for those pressures.

Torque Specs and Fluid Capacities – Where to Find Them

Torque values are scattered throughout the hydraulic section and the engine service parts. For example, the boom cylinder assembly lists bolt torques. The hydraulic control valve assembly gives you the pattern and torque for the valve body bolts. Capacities for fuel tank, hydraulic system, engine oil, and travel motor are in the service schedule and the maintenance sections. The manual uses imperial units – foot-pounds, inches of water, psi. No metric conversion table in there, but if you are working on a Bobcat you are using inch-pound tools anyway.

I will say this: never trust a torque spec from a forum. I had a kid last week use 45 ft-lbs on a control valve manifold bolt because some YouTube video said it. The spec in the factory manual is 22 ft-lbs. Guess what happened when he started the machine? Oil sprayed everywhere. Buy the factory manual so you get the real numbers.

FAQ

Does this manual cover the engine serial number location?

Yes. The Serial Number Locations section includes both the excavator serial number and the engine serial number. Page numbers are listed in the alphabetical index.

How do I remove air from the fuel system after replacing the filter?

The Fuel System section has a procedure called “Removing Air From The Fuel System.” It tells you to fill the filter with clean fuel, install it, then loosen the bleeder screw on the injection pump. Crank the engine (make sure the tailgate is closed and the machine is blocked) until fuel comes out without bubbles. Tighten the bleeder screw and start the engine. Let it run at half throttle for two minutes. If the engine misses, repeat the procedure. Do not spray fuel on hot exhaust – the fire prevention section covers that. Always vent exhaust to outside if running inside. The manual also includes fuel specifications and the correct way to drain the tank. I have used this procedure dozens of times on Bobcat excavators and it works every time if you follow the order of operations.

You will also find related manuals for other Bobcat models if your fleet includes earlier machines: Bobcat 320 320L 322 2006 Service Manual and Bobcat 320 322 2006 Service Manual cover similar platforms. For the older generation, check Bobcat 320 322 1997 Service Manual. If you need background on drivetrain concepts outside of hydraulics, the Manual Transmission resource is useful, and for general powertrain theory the Manual Transmission article can fill in gaps.

Do not waste time with aftermarket reprints that omit pages or copy the hydraulic schematic in low resolution. This is the real factory file – 642 pages, 2006 publication, original Bobcat part number 6903818. Access the Factory Manual and keep it on your shop tablet. Your excavator will run longer, and your knuckles will thank you.