Description

Sisudiesel 645 2002 Workshop Manual – Factory Procedures and Torque Specs

If you’re tearing down a Sisudiesel 645 engine without the factory manual, you’re gambling with cracked blocks and bent valves. I’ve seen it. Guys bolt heads on using aftermarket specs, and then wonder why the coolant mixes with oil. The Sisudiesel 645 2002 Workshop Manual stops that nonsense cold. This is the same binder that sits on the bench at Sisu Diesel – 76 pages of Finnish engineering, in English, with the torque sequences and clearances that actually match the parts in your hands.

Engine Specifications and Technical Data

Page 0-7 carries the cylinder liner and block dimensions you need before you order a rebuild kit. The manual gives you the exact bore limits, liner protrusion, and surface finish callouts. Skip measuring that, and you’ll be pulling the head again inside 500 hours. The TECHNICAL DATA section (pages 0-7 through 0-10) also covers camshaft journals, connecting rod big-end bore tolerances, and timing gear backlash. Every number is from the factory, not a reprint from a third-party copy. The Engine specifications on page 0-6 list firing order, injection timing, and oil capacity – all in Imperial units as they left Finland.

Cylinder Head and Valve Mechanism: Factory Clearances

Section 4 (Valve Mechanism) tells you the exact valve clearance settings for intake and exhaust. The manual lists both cold and hot adjustment figures. I’ve seen guys rely on generic diesel engine guides – they end up with burnt seats because the valve lash was too tight. The factory procedure includes the sequence for tightening rocker arm shafts. If you need the special tools listed on page 0-4, the part numbers are there. Don’t try to fudge it with a pry bar and a feeler gauge that’s been hammered flat.

Crankshaft and Connecting Rods: Measuring and Fitting

Section 5 (Crankshaft) on page 0-9 provides the main bearing journal diameters and oil clearance ranges. The manual also includes the thrust bearing end-play spec. For connecting rods (section 6), it gives the big-end bore and side clearance. You’ll also find the exact torque values for the rod bolts – step-tightening patterns included, not just a single number. If you rebuild a 645 without these pages, you’re flying blind. One bad rod bolt torque and the window in the block is permanent.

Fuel System Diagnostics: The Manual’s Test Equipment Section

Section 14 – Fuel System Test equipment – is worth the price alone. It covers injection pump pressure settings, injector opening pressures, and the lift pump flow rate. The manual specifies the test bench adapters and gives calibration data for the Bosch-type system on this engine. Without this section, you’re relying on guesswork when a customer complains about low power. The troubleshooting table walks you through air in the Fuel lines, stuck plungers, and timing deviations.

Cooling System and Lubrication: Don’t Overlook These

Section 11 (Cooling System) and Section 10 (Lubrication System) contain the flow diagrams and pressure specs. The coolant capacity, thermostat opening temperature, and water pump seal replacement procedure are all documented. For the lube system, you get the oil pump clearance checks and relief valve spring specs. Many guys skip the oil pressure test procedure – not good when the Cooling and lube systems are tied to the same overheating issue. The manual pulls it all together.

Why OEM Documentation Beats Aftermarket

I’ve had customers hand me printouts from generic online sources – the firing order was wrong, the head bolt torque was 20 ft-lb low. This manual comes from Sisu Diesel Inc. directly. The SAFETY INSTRUCTIONS on page 0-3 cover lifting the engine, handling high-pressure fuel, and electrical system disconnection. Aftermarket manuals leave that out and charge you for pages of fluff. You get the real thing: construction drawings, exploded views, and the original part numbering.

Related Sisudiesel manuals you might need:

• SisuDiesel Fortius Series Engines Workshop Manual”>SisuDiesel Fortius Series Engines Workshop Manual
• SisuDiesel Citius Series 44 49 66 74 84 Workshop Manual”>SisuDiesel Citius Series 44 49 66 74 84 Workshop Manual

If your job involves the driveline, check our guides for the Manual Transmission and Manual Transmission as well – proper clutch and gearbox data pairs with this engine manual for a full powertrain overhaul.

Does this manual include wiring diagrams?

No. Section 15 covers the electrical system but does not contain full wiring diagrams. It gives component locations and test points.

Can I use this manual for the Sisudiesel 634 engine?

No. The 634 engine is a different platform. While some principles are shared, the bore, stroke, injection timing, and torque values are different. Using the 645 manual on a 634 will lead to incorrect clearances and potential engine damage. You need the specific manual for that engine model. The SisuDiesel 320 420 620 634 Engines Workshop Manual”>SisuDiesel 320 420 620 634 Engines Workshop Manual is what you want for those engines.

You don’t have to take chances with your next Sisudiesel 645 rebuild. Access the Factory Manual from AutoRepairManuals and keep the spec sheet on your workbench where it belongs.