1999 Cummins B3.9 & B5.9 Diesel Engine Troubleshooting and Repair Manual (P/N 3666087-01)

The Cummins Troubleshooting and Repair Manual for B3.9 and B5.9 Series Engines, Bulletin No. 3666087-01, is the October 1999 edition for four- and six-cylinder B Series diesels in automotive and nonautomotive applications. It focuses on engine diagnosis and in-chassis repair. Complete component and assembly rebuilding is addressed in the separate engine shop manual.

• Engine mechanical repair: Cylinder-head removal and inspection, rocker-lever service, overhead adjustment, cam followers and tappets, piston and bearing inspection, and hydraulic pump drive service.

• Fuel-system diagnosis: Rotary and in-line injection-pump identification, removal and installation, pump timing, fuel-flow checks, and cold-start timing advance diagnosis.

• Injectors and fuel lines: Injector disassembly, inspection, opening-pressure and spray-pattern testing, fuel-line restriction checks, and fuel return overflow valve inspection.

• Lubrication and cooling: Oil-pressure diagnosis, oil-pump and cooler service, thermostat testing, cooling-system pressure tests, and air or combustion-gas leak checks.

• Intake, turbocharger, and exhaust: Charge-air cooler testing, turbocharger clearance and seal checks, wastegate actuator procedures, and exhaust restriction measurement.

• Compressed air: Holset compressor unloader service, air-governor tests, leak diagnosis, and SS191 and QE cylinder-head procedures.

• Starting and charging: Starter and alternator tests, magnetic-switch and solenoid checks, battery-cable diagnosis, and component-specific wiring diagrams.

This manual is suited to experienced diesel service technicians with the specified test equipment; its troubleshooting section expressly requires trained, experienced technicians.

Symptom Charts and Mechanical Repair

The diagnostic logic trees connect probable causes to corrective actions and numbered repair procedures. They address hard starting with or without exhaust smoke, low power, rough running, surging, abnormal combustion noise, overheating, oil-pressure faults, and air-compressor complaints. This lets a technician follow a symptom into the relevant component test rather than treating a low-power complaint as an injection-pump failure by default.

Mechanical sections cover the cylinder block, cylinder head, rocker levers, and cam followers/tappets, with inspection limits and multi-stage cylinder-head bolt tightening sequences. Fuel Pump Side View and Turbocharger Side View illustrations identify external components; gear-alignment drawings and the connecting-rod Side Clearance Limits table support internal inspection.

Injection-Pump Variants and Injector Service

Pump coverage distinguishes Bosch P7100 and A-RSV in-line units, Nippondenso EP-9, Bosch VE, Lucas CAV DPA/DPS, and Stanadyne DB4 configurations. Timing material includes spill-port timing and pump-to-engine gear-mark selection. Governor performance verification requires qualified personnel and special equipment; rating changes are referred to separate injection-equipment literature.

Injector procedures extend through cleaning, inspection, assembly, opening-pressure testing, leakage testing, and chatter evaluation. Tool references include injector puller 3823276 and engine barring gear 3377371.

The injector-removal cautions explain how a rust-bound injector can rotate and score the cylinder-head bore. The fuel return overflow valve section also identifies a sticking check ball or spring as a cause of low power.

Cooling, Boost, and Compressed-Air Diagnosis

Cooling-system coverage separates thermostat faults, air entry, combustion-gas leakage, and coolant contamination. Lubrication sections provide oil-pressure checks and oil-cooler inspection rather than relying on fluid-capacity tables alone.

Charge-air cooler procedures include pressure, leakage, and temperature-differential tests. Turbocharger inspection distinguishes axial clearance, radial bearing clearance, blade damage, and compressor or turbine seal leakage. The cooler-cleaning cautions explain that retained debris following a turbocharger failure can damage the engine.

Holset coverage includes unloader and cylinder-head work. Complete compressor internal rebuilding is referred to separate compressor documentation.

Electrical Tests and Engine Performance Checks

Electrical illustrations include the Starter Solenoid Wiring Circuit and Typical Bosch K1 Charging System Circuit, alongside Delco Remy and Nippondenso starting-motor diagrams. These support the accompanying voltage, resistance, and charging-output checks.

Engine testing covers chassis and engine dynamometer checks, run-in procedures, and crankcase blowby measurement. Vehicle and equipment faults require the applicable OEM documentation.

High-pressure fuel, hot coolant, rotating equipment, and heavy engine components require the safety precautions specified for each procedure.

A Preview of Boost-System Inspection Limits

For charge-air cooler pressure testing at rated engine speed and load, the manual specifies a maximum differential of 21 kPa [3 psi] between the turbocharger outlet and intake manifold.

Turbocharger shaft end-play specifications distinguish units before S/N 840638, with a range of 0.10–0.16 mm, from units at S/N 840638 and later, with a range of 0.03–0.08 mm. These separate limits prevent different turbocharger builds from being assessed against one generic clearance.

Bookmarks, Diagram Detail, and PDF Contents

Section navigation and wiring detail: Embedded PDF bookmarks provide access to systems and individual procedures. PDF text search is unavailable. Small labels in the inspected starting and charging diagrams are readable with magnification.

Supplied as one printable English-language, 928-page PDF. The total includes the front and back covers, notes and blank pages, and one nontechnical promotional page; these pages are already included in the stated count.