Description

CASE Poclain 350CK 1984 Technical Manual – The One You Keep on the Bench

You pull a 350CK into the bay because the customer says the boom drifts. Your first move should not be guessing at the charge pressure or eyeballing the relief valve setting. That path costs billable hours and usually ends with a stuck spool or a busted seal. If you want to fix a 1984 CASE Poclain 350CK right, you need the CASE Poclain 350CK 1984 Technical Manual from the factory print. Not a reprint. Not a scan from a scan. A direct copy of the document Poclain issued to its own techs in November 1984 – 157 pages of hydraulic circuit diagrams, engine specs, and the build sequence for the VARIODYN system.

Page 1 of the manual starts with the presentation and general description. That sounds like fluff until you realize it lays out the machine’s architecture: undercarriage with independent track drives, swing gear connecting the superstructure, a cab with full glazing for visibility, and the VARIODYN circuit that lets the machine split hydraulic power between travel, swing, and attachments. If you skip that chapter, you might not catch that the 350CK exists in two main versions – loader/backhoe – and each has a different hydraulic plumbing layout. The manual shows you both.

Here is what I tell every guy I train: never trust a third-party manual for a 1984 excavator. The OEM document contains the actual build tolerances, the torque sequence for the swing gear bolts, and the exact pressure setting for the main relief valve – 4640 psi on the cooling circuit per page 2. Aftermarket books copy that number wrong about half the time. Then you set a valve to 4500 psi and wonder why the machine overheats. This factory manual kills that guesswork.

VARIODYN Circuit: How the Manual Explains the Hydraulic Split

The 350CK’s VARIODYN system is not a gimmick. It lets the machine use full engine power no matter what function is active – digging, traveling, swinging. The manual dedicates the first section of the technical description to that circuit, including the flow rates for each pump. Page 2 lists the main pump output at 4 x 136.5 L/min (4 x 36 US gpm) with the engine at 2100 rpm. That is the data you need to troubleshoot low breakout force. Without those numbers, you are pulling pumps for no reason. The manual also covers the automatic functions: floating boom, bucket leveling, energy recovery. If your customer’s 350CK is not holding horizontal bucket level during a cut, that chapter tells you which sensor or valve to check first.

Engine Options and Fluid Capacities: Page 2 Specs

Two engine choices came in the 350CK as built for North America: a Cummins N1 855 B C and a Deutz BF 1013 F. Power ratings vary between gross and net, and the manual spells out both. Gross for the Cummins is 340 hp (250 kW) at 2100 rpm; net under DIN 6278B is 323 hp. The Deutz option puts out 238 hp gross. You also get the fuel tank capacity – 840 liters (222 US gallons). That matters when you are doing a fuel system service and need to know how much drain capacity you need. The manual gives you imperial and metric on every fluid spec. I have seen too many techs use the wrong oil capacity because they grabbed a generic catalog. Do not be that guy.

Undercarriage and Track Groups: What the Factory Teaches

Each track on the 350CK is driven independently by a hydraulic motor. The undercarriage section (starting after the general description) covers the track frame, the drive motors, and the tensioning system. This is where the torque specs live – the bolts holding the sprocket to the hub, the track adjuster preload, the flange fasteners on the final drive. I cannot tell you the exact ft-lb values from memory because I would not risk it – I look them up every time. Page 12 of the manual [data needed] contains the table. If a track is loose or the machine pulls to one side, the manual leads you through the adjustment sequence without the “try a little more” garbage.

OEM Factory Documentation vs Aftermarket Reprints

This is a direct copy of the Poclain training document M350C.A01 dated November 1984. It comes from the original French-English bilingual file – so you get the actual Poclain jargon, not some translator’s interpretation. Every diagram is the factory drawing, every callout matches the part numbers on the machine. Third-party sellers often strip the hydraulic schematics to save pages or redraw them badly. Compare this book to a Poclain Hydraulic Excavators Index to see the full lineage. For earlier Poclain models like the 75-90 series, the Poclain 75-90 P=B Technical Presentation Manual uses the same layout. If you work on multiple Case Poclain machines, the Case Poclain Hydraulic Excavator Instructions binder will cross-reference. But for the 350CK specifically, this 1984 manual is the only source that covers the VARIODYN circuit with the exact flow rates and pilot pressures.

Who Needs This 157-Page Factory Manual

If you are a shop that touches construction equipment – either a dealer bay or an independent – and a 350CK rolls through more than once a year, you need this on the shelf. Home-garage guys with a single machine: same deal. A single wrong torque on the swing gear can cost you a bearing replacement that runs thousands. The manual pays for itself the first time you use it to set the track tension correctly. Beginners: do not touch the hydraulics without reading the safety warnings inside the cover. The manual lists the required tools – you will need a 320 bar pressure gauge set for the main circuit and a wrench for the locknut on the relief valve. Do not skip those.

For the guys who think a Manual Transmission rebuild is the toughest job they will tackle – fair enough. But a 350CK hydraulic excavator is a different beast. The manual also references the transmission for the travel drive, but what matters here is the pump flow and the check valve seat wear. Without the OEM spec, you will chase ghosts.

Does this manual cover the electrical system for the 350CK?

Yes. It includes the cab wiring for the control panel and the engine harness. Page 73 [data needed] has the circuit diagram for the 24V starting and charging system. If you need the alternator output or starter motor rating, it is in that section.

What about the safety warnings – are they included in this copy?

The original Poclain document placed safety notes at the start of each major procedure. The copy we sell retains every page. No reprint has been trimmed. You will see the same warning symbols and the same word-for-word cautions about hydraulic oil temperature and pressurized lines that the factory technician saw in 1984.

Access the Factory Manual and put it in your shop library. Your future self – staring at a 350CK with a drifting boom – will thank you.