Description

Caterpillar 3304 1975 Parts Catalog

You’re pulling a 3304 apart in the bay and you hit the fuel system. The injection pump comes off, and now you need the exact part number for the delivery valve. Not a cross-reference from a third-party website. You need the factory number that matches the serial number stamped on your block. That’s where this Caterpillar 3304 1975 Parts Catalog earns its place on your bench. 249 pages of group breakdowns, from the central structure to the gasket kits. Original OEM data from Caterpillar’s Publications Division.

Aftermarket catalogs? I’ve seen them send a mechanic the wrong oil cooler part because they misread the serial number break. This book tells you exactly which illustration applies to your engine’s serial number range—78P1-up. The serial number plate is on the left side of the cylinder block. You can confirm that on page 2 of the book. That’s the kind of detail that keeps a job from turning into a parts run.

What the Caterpillar 3304 1975 Parts Catalog Covers

The Quick Reference Guide lists major sections: Central Structure, Upper Structure, Front Structure, Rear Structure, Lower Structure, Lubrication System, Cooling System, Intake & Exhaust System, Fuel System & Governor, Electrical System, Gasket Kits. Each section breaks down into individual components with part numbers. The alphabetical index on page 3 directs you to specific groups. You want the camshaft? Page 36. Crankshaft bearings? Page 30. It’s all in there.

Cooling System: Water Pump and Oil Cooler

The cooling section starts on page 83. It covers the water pump, engine oil cooler, transmission oil cooler, and all the water lines and elbows. Each illustration has its own parts list with indented part names. If you need the housing and regulator, it’s right there. This is not a generic diagram—it’s specific to the 3304 vehicular engine. You get the exact part numbers for the water pump assembly, the bolts, the gaskets. Makes ordering from your Cat dealer a ten-minute phone call instead of a guessing game.

Fuel System & Governor: Injection Pump and Lines

Pages 120 through 202 cover the fuel system and governor. That’s 82 pages dedicated to the fuel injection lines, fuel transfer pump, fuel priming pump, governor cover, and the governor and fuel injection pump assembly. There’s a separate section for torque control on page 196. If you’re rebuilding the injection pump, you need the fuel injection lines section (page 188) to get the correct tube assemblies. The parts list includes the part numbers for each line—no guessing which one goes to cylinder 3. Related? Check the Caterpillar 3304 Service Manual – 136 Pages of Factory Torque Specs for the actual installation torque values.

Electrical System: Alternator and Starting Motor

Starting on page 203, the electrical system covers the alternator (page 213), electric starting motor, and glow plug. Each component has an illustration with a parts breakdown. The alternator section lists the brush kit, the rectifier, the regulator—everything. If you’re swapping a starter, you get the mounting bolts and the drive housing parts. No aftermarket catalog gives you this level of granularity. For a broader view of automotive electrical systems, you can read the Automotive Industry Overview but for the actual part numbers, stick with this book.

Upper Structure: Cylinder Head and Valve Mechanism

Page 37 starts the upper structure section. Cylinder head, cylinder head fasteners, lifting eye, valve mechanism and cover. The parts list for the valve mechanism includes the valves, springs, retainers, and seals. You need the cylinder head gasket? It’s in the gasket kits section on page 215. That’s 30 pages of gasket kits covering every system in the engine. I’ve seen mechanics try to reuse head gaskets because they didn’t have the right part number. Not with this catalog.

249 Pages of Factory Part Numbers

Each major section in the Quick Reference Guide is represented. Lubrication system (page 71) includes the oil pump, oil filter, oil lines, breather, and fumes disposal. Lower structure (page 68) covers the oil pan and fasteners, oil level gauge. Front structure (page 41) includes the front gear timing, pulley, support, trunnion, and fan drive. Rear structure (page 63) covers the flywheel. If you’re rebuilding the entire engine, you’ll need every one of these sections. For other Cat engine models, see the Caterpillar C15 2006 Parts Catalog – Factory OEM 884 Pages or the Caterpillar Elevated Sprocket Tractors Parts Catalog – 971 Pages.

Short paragraph: This catalog is 249 pages of pure OEM part data. No reprints.

Page 2 of the book has a dedicated section on ordering parts. It says: “When ordering parts, always use the Parts Book covering the serial number of your machine.” That means you need your engine’s serial number (78P1-up) and the arrangement number from the plate. The book also has an alphabetical index on page 3 to find any group name. If you need a balancer, look up “Balancer” and it sends you to page 36 in the central structure. This system works because it’s designed by the people who built the engine. Not some third-party compiler. The Automotive Industry Overview covers general history, but this book covers real parts.

FAQ

Does this catalog cover every nut and bolt on the 3304 engine?

Yes. All serviceable parts in the central, upper, front, rear, lower structures plus lubrication, cooling, intake/exhaust, fuel/governor, electrical, and gasket kits. 249 pages.

How do I know which illustration applies to my engine if there are multiple types?

The captions under each illustration specify the serial number range for your engine. If the caption says “First Type” or “Second Type,” you need to physically compare the actual group or assembly on your engine to the illustration to determine which one matches. The book also uses indented part names to identify each serviceable part in the parts list. There’s a vehicle usage chart on page 11 showing which machines use this engine and an engine arrangements listing on page 12 showing specific build configurations. This is factory-level documentation with serial number breaks. If you have the 78P1-up serial number, you’re covered. Always confirm the arrangement number from the plate on the cylinder block.

You need to get this right the first time. One wrong part number and you’re waiting on a restock order. The factory parts catalog eliminates that. Access the Factory Manual now and keep it on your tablet or print the pages you need. Your 3304 will thank you.