Description

Cummins B3.9, B5.9, B4.5, B4.5 RGT 2013 Service Manual

If you’ve ever pulled a head bolt on a Cummins B-series and guessed the torque because the aftermarket book was wrong, you know the cost. That’s why this Cummins B3.9, B5.9, B4.5, B4.5 RGT 2013 Service Manual exists. 740 pages of factory-sourced procedures, torque tables, and diagnostic charts. No guesswork. Each section comes from the same engineering that built the engine. Aftermarket documentation? I’ve seen torque specs off by 20 ft-lb. That strips threads, leaks coolant, and costs billable hours. This manual fixes that.

Cummins B3.9, B5.9, B4.5, B4.5 RGT 2013 Service Manual: Engine Testing Procedures

Group 14 covers Engine Testing. That’s where you confirm the repair actually worked. The manual walks through compression checks, fuel pressure tests, and governor adjustments. You get the factory pass/fail thresholds, not some generic range. For example, the coolant temperature above normal symptom table on page 1 lists causes like “low coolant level” and “engine is receiving too much fuel” – with exact correction steps. That’s the difference between a job that gets done in one pass and a callback three days later.

Fuel System – Group 05: Injectors and Fuel Lines

The Fuel system section starts on page 5. Group 05 – Fuel System and Group 06 – Injectors and Fuel Lines. This is where you find the high-pressure injection pump specs, injector timing, and fuel return line diagrams. Need the charge pressure? Page 5 lists the specifications for the B3.9, B4.5, and B5.9. The manual also includes Group 12 – Compressed Air System, which matters if the engine runs air-start or air-driven accessories. Every fuel line routing, every o-ring size, every torque value is printed from the OEM file. No third-party redraws that miss a banjo bolt shoulder.

Coolant Temperature Above Normal: What Page 1 Tells You

Overheating diagnostics are not a guessing game. The symptom chart on page 1 gives you nine possible causes in order of likelihood. Collapsed radiator hose, dirty engine exterior, loose fan drive belt – each with a correction reference. The manual also cross-references Group 07 – Lubricating Oil System and Group 08 – Cooling System. If the oil level is too high or too low, the chart sends you to the correct section. That kind of organization comes from years of field experience at Cummins. You don’t get that from a PDF put together by someone who never turned a wrench.

740 Pages of OEM Data

This is not a condensed pocket guide. 740 pages cover every system: Group 10 Air Intake, Group 11 Exhaust, Group 13 Electrical Equipment. The electrical section includes wiring diagrams for the ECM, starter, and alternator circuits specific to the B4.5 RGT. Group 09 Drive Units covers the front gear train and accessory drives. You also get Group 17 Miscellaneous – component suppliers and service literature (Section L). The foreword (page 3) explicitly states: “This manual contains instructions for troubleshooting and repairing this engine in the chassis, complete rebuild procedures and specifications.” That includes disassembly, cleaning, inspection, and assembly. If you’re rebuilding a B5.9 from the block up, this is the document you need.

Does This Manual Cover Wiring and Electrical?

Yes. Group 13 – Electrical Equipment. It covers the starting motor, alternator, and engine control module wiring. The diagrams are system-level, showing pinouts and wire colors. For a manual transmission application, you may need additional vehicle-specific wiring, but the engine-side harness is all here. If you’re dealing with a manual transmission failure, check Manual Transmission fundamentals separately – this book stays focused on the engine. For the transmission itself, Manual Transmission resources cover clutch and gearbox specifics.

Source Authenticity: OEM vs Aftermarket

This manual was printed by Cummins Inc. in November 2013 (Bulletin 3666087). The copyright page says “Copyright © 2013 Cummins Inc.” That means every specification came from the engineers who designed the injection pump and the pistons. Aftermarket manuals often lift data from older editions, miss updates, or use inferred values. I’ve seen aftermarket books list the same torque for B3.9 and B5.9 head bolts – those are different thread pitches. Only the factory manual distinguishes them. You also get access to the Component Manufacturers list in Section M, so you can order genuine Cummins or ReCon parts. That alone justifies the price.

How many pages does this manual have?

740 pages.

Does this manual cover the B4.5 RGT engine?

Yes. The B4.5 RGT is explicitly listed on every page header, and the fuel system and air intake sections include RGT-specific turbocharger and wastegate adjustments.

What years does this manual apply to?

Published in 2013, it covers engines built up to that date. The foreword states specs are based on information at time of printing. If you’re working on a late-model B-series with emissions aftertreatment changes, you may need a later supplement. However, the core mechanical rebuild procedures – pistons, rings, bearings, camshaft – haven’t changed significantly for these models. The manual includes group references for all previous updates. For the B3.9 and B5.9, this edition remains the standard reference used by Cummins-authorized repair shops. It also lists the 1-800-DIESELS hotline for any discrepancies.

Can I use this manual for a Cummins B3.9 with a manual transmission?

Yes. The engine-side procedures are identical regardless of transmission type. The manual covers flywheel housing bolt patterns (Group 16 Mounting Adaptations). For clutch and transmission service, refer to Cummins B3.9 and B5.9 Series Engine Operation Manual, Cummins B3.9 B4.5 B5.9 Series Engines Operation Manual, and Cummins B3.9 B4.5 B5.9 Operation and Maintenance Manual for operation-specific guidelines.

Don’t trust a repair to a hacked-together PDF. Access the Factory Manual now and keep the torque spec card next to your torque wrench. Your time is worth more than a comeback.