Perkins 4.108, 4.107, 4.99 Workshop Manual

If you’re working on a Perkins 4.108, 4.107, 4.99 and you don’t have the factory manual on the bench, you’re asking for trouble. I’ve seen too many guys wing it with aftermarket garbage and end up with a head gasket leak because they guessed the torque sequence. The Perkins 4.108, 4.107, 4.99 Workshop Manual is 114 pages of OEM specs – no reprints, no third-party interpretations. It’s what Perkins ships to their own dealers. This isn’t a condensed consumer booklet; it’s the full service procedure for the 4.108, 4.107, and 4.99 diesel engines used in everything from generators to marine auxiliaries. Below I’ll break down what you actually get inside.

Cylinder Head and Crankshaft Service – Factory Procedure

Section E is devoted to the cylinder head – removal, inspection, valve grinding, and refitting with correct tightening order. Section H covers the crankshaft and main bearings. On page 3 of the foreword, Perkins makes a point you rarely see elsewhere: when you install setscrews or studs into holes tapped through to the inside of the engine, you must use a suitable sealant on the threads. Miss that step and you’ll chase an oil leak for weeks. The manual also tells you which sealant to use, though it refers you to the Approved Service Tools list at the back. The technical data in Section B gives you the bore, stroke, and compression ratios – no aftermarket summary, just the factory numbers.

Does This Manual Cover the Fuel Injection System?

Yes – Section N covers the air cleaners and fuel system, including the injection pump, injectors, and fuel filters. Perkins designs these engines with specific timing marks and pump settings. The manual walks you through removal and installation of the fuel injection pump with the correct phasing. You won’t find a generic “remove pump” instruction; it details the locking pin location and timing case alignment. If you’re swapping injectors, the torque for the injector clamp bolts is in the technical data – again, no guesswork.

7 Major Systems Broken Down by Chapter

The TOC lists sections A through R, but the core service sections are: Cylinder Head (E), Pistons & Connecting Rods (F), Cylinder Block & Liners (G), Crankshaft & Main Bearings (H), Timing Case & Drive (J), Timing (K), Lubrication System (L), Cooling System (M), Fuel System (N), Flywheel & Flywheel Housing (P), and Electrical Equipment (Q). That’s 11 sections of real hands-on procedure. Section R is a dedicated section for engines used in refrigeration units – a niche but valuable addition for marine and industrial applications. This manual doesn’t cut corners; it covers the whole engine from the front cover to the flywheel housing.

Cooling System: What the Manual Covers

Section M is the cooling system chapter. It includes the water pump, thermostat, and coolant flow diagrams. For marine installations, the raw water pump is covered here as well. One thing I appreciate: they specify the coolant capacity in imperial quarts and give the correct antifreeze concentration for different ambient temperatures. If you’re doing a full rebuild, you need these numbers to get the cooling system right – otherwise you risk overheating and cracked heads. The manual also references the approved service tools, so you know which puller to use on the water pump pulley.

Get the Right Torque Data from Section B

Technical Data (Section B) is where you live during a rebuild. It lists tightening torques for the cylinder head bolts, main bearing cap bolts, connecting rod nuts, flywheel bolts, and more. All in lb-ft – imperial units, as required. No metric conversion tables from a 1992 Chilton book. This is the genuine Perkins data, verified at the factory. If you’re torquing head bolts on a 4.108, you need the two-stage sequence and final angle – it’s all here. I’ve seen guys use a generic table and strip the threads in the block. Don’t be that guy.

FAQ

Can I use this manual for the marine version of the 4.108?

Yes – Section R is dedicated to refrigeration unit engines, which covers marine auxiliary applications.

What about the electrical system – does it include wiring diagrams?

Section Q covers the electrical equipment – alternator, starter motor, glow plugs, and the wiring harness for the engine itself. It does not include full vehicle or boat wiring diagrams; that’s chassis-specific. However, it gives you the component specifications, terminal identification, and test procedures. For example, it tells you how to test the glow plug circuit resistance and the starter solenoid pull-in winding. If you need to tie the engine into a new installation, this section gives you the pinouts you need. The manual also lists the approved service tools needed for electrical work, like the special puller for the alternator pulley. That level of detail is why I keep this manual on the shelf.

Stop wasting time chasing specs from forum posts and second-hand PDFs. Access the Factory Manual for your Perkins 4.108, 4.107, or 4.99 and get the OEM data on your screen before you turn another bolt.

Related Manuals

• Perkins 4.108 4.107 4.99 1983 Workshop Manual
• Perkins 4.108 4.107 4.99 Marine Engines Workshop Manual
• Perkins 4.108 4.107 4.99 Diesel Engine Workshop Manual

If your job involves the transmission, note that the engine manual doesn’t cover the Manual Transmission – you’ll need a separate workshop manual for that. For a complete drivetrain rebuild, pair this engine manual with the Manual Transmission manual from the same OEM source.