Description

Cummins B3.9, B5.9, B4.5, B4.5 RGT 2013 Service Manual – OEM Factory Specs

Every time I see a DIYer trying to pull a cylinder head off a B-series Cummins without the factory torque sequence, I cringe. That’s how you warp the deck or snap a bolt. This manual – the Cummins B3.9, B5.9, B4.5, B4.5 RGT 2013 Service Manual – is what you need on the bench. Not a generic scan from a forum, not a third-party rewrite. This is the actual 724-page factory document printed by Cummins in 2013. It tells you exactly how to disassemble, inspect, and rebuild these engines without guesswork.

What This Manual Covers – 724 Pages of Real Content

You get Volume 1 of the B3.9, B4.5, B4.5 RGT, and B5.9 service manual. The table of contents runs from Introduction through Section M. There’s a whole section on engine and system identification, familiarization, and a troubleshooting symptom table that’s worth the price alone. Then it dives into Complete Engine – Group 00, which includes disassembly and assembly procedures. Cylinder Block – Group 01, Cylinder Head – Group 02, Rocker Levers – Group 03, and Cam Followers/Tappets – Group 04 are all there. That’s the core of an in-frame or out-of-frame rebuild. Each group has its own step-by-step sequence, required tool lists, and torque values. Page 1 shows a troubleshooting table for coolant temperature above normal – it lists causes from low coolant to a collapsed radiator hose, with corrections that reference later sections.

Troubleshooting Symptoms – Coolant Temp Above Normal

Got an overheating B3.9 in a delivery truck? Open to the Troubleshooting Symptoms section. The manual walks you through low coolant, collapsed hose, wrong oil level, excess fuel, dirty engine, loose fan drive, radiator shutter – each with a correction. It doesn’t guess. It tells you to check the fan drive belt tension with a specific gauge. That level of detail is what separates this from a Chilton’s. If you’re chasing an electrical gremlin, you’ll need a Manual Transmission diagram from another source, but the engine mechanical side is covered here cold.

Engine Disassembly – Group 00: Where Most Guys Mess Up

Group 00 covers the complete engine removal and teardown. You’ll find the order to pull the front gear train, the sequence for the cylinder head bolts (three-pass torque-to-yield), and the exact method to support the engine when the bell housing is off. The manual includes a parts cleaning and inspection section that most aftermarket books skip. It tells you to mic the cylinder liner protrusion and gives the spec in thousandths. No “clean thoroughly” – it lists solvents and tools. That’s why OEM documentation matters.

Cylinder Block and Cylinder Head – Torque Specs You Can Trust

The cylinder block group covers main bearing bore inspection, liner installation, and cooling passages. Cylinder head group includes valve seat angles, stem height, and the torque sequence for the head bolts. Those numbers come straight from Cummins engineering, not from a copy that someone transcribed wrong. I’ve seen aftermarket manuals list head bolt torque as 90 ft-lb for the B5.9 when factory spec calls for 75 plus a 90-degree turn. This manual gets it right. If you’re pairing this with a Cummins B3.9 and B5.9 Series Engine Operation Manual, you’ll have the complete package for both running and rebuilding.

Why OEM Documentation Beats Aftermarket Copies

Third-party manuals often reprint the same diagrams with blurred torque charts. This one comes from Cummins Inc., Bulletin 3666087, printed November 12, 2013. The copyright is clear. Every specification is traceable. When you see a warning in the General Safety Instructions, it’s not a paraphrase – it’s the actual factory safety language. If you question a torque value, you can call 1-800-DIESELS with the bulletin number and verify it. You can’t do that with a Haynes. For related operation guidance, check the Cummins B3.9 B4.5 B5.9 Series Engines Operation Manual or the Cummins B3.9 B4.5 B5.9 Operation and Maintenance Manual for daily use procedures.

Who Needs This Manual – And Who Doesn’t

If you’re rebuilding a B3.9 for a skid steer or a B5.9 in a school bus, this manual is mandatory. If you’re just changing oil and filters, you don’t need 724 pages – get the operation manual instead. The audience here is the guy who wants to pull the head, replace liners, set valve lash, and do it right. Beginners should read the entire Foreword and Safety section before touching the engine. Ignoring torque sequences will cost you a head gasket within 500 miles.

For external circuits like the Manual Transmission or PTO, you’ll need separate documentation. This manual stays focused on the engine block, cylinder head, rocker levers, and cam followers. No transmission or driveline content.

FAQ

Does this manual include torque specs for head bolts on the B4.5 RGT?

Yes. Cylinder Head – Group 02 gives the full torque sequence and angle specifications for all models including the B4.5 RGT. Follow three-pass tightening: 75 ft-lb, 90°, then 90°.

Can I use this manual for a 1998 B5.9 Mechanical engine?

This manual covers 2013 model year and earlier engines with the same architecture. If your serial number falls within the B5.9 range, the disassembly and assembly procedures apply. Check the identification section.

Is there a wiring diagram section?

No. This is a mechanical service manual. Electrical schematics for sensors and harnesses are covered in a separate electrical troubleshooting manual. You will not find pin-out diagrams here.

How is the manual delivered?

Digital PDF format. 724 pages, searchable, watermarked per user. No physical copy. You get immediate access after purchase.

This is the factory document that every shop should have on a tablet if they work on Cummins B-series engines. Forget printed copies that wear out; the PDF stays sharp. You can zoom into a torque chart on page 26 and see the decimal. Get the manual that doesn’t make you guess. Access the Factory Manual now and stop borrowing internet screenshots.