Description

Yanmar YB401, YB401-2, YB401(-2)-UC, YB401(-2)-UZP 1992 Parts Catalog

Digging through aftermarket parts lists for a Yanmar YB401, YB401-2, YB401(-2)-UC, YB401(-2)-UZP 1992 Parts Catalog? That’s a fast track to ordering the wrong hydraulic seal. I’ve watched guys spend a morning pulling a swing cylinder apart only to find the aftermarket diagram swapped the port fittings. This 188-page factory catalog from Yanmar kills that guesswork. It’s not a repair manual—it’s the parts bible. Every bolt, hose, and gasket is listed by number, grouped by assembly, and keyed to machine serial ranges. If you wrench on these crawler backhoes, you need this on your bench.

What’s Inside: 188 Pages of Factory Data

Yanmar split this catalog into sections by major assemblies. You get the full parts breakdown for the engine, undercarriage, hydraulic system, cab, and attachments. The preface (page 1) gives the machine number cutoff—YB401 from 00501, YB401-2 from 20501. Paint colors are listed with Munsell numbers and spray can codes for both old and new finishes. That alone saves you from guessing which yellow is correct. The specification table on page 2 covers transport dimensions, bucket capacity, digging force, and engine model 4TNA78TL-D(R)B. Need the track shoe width? It’s 350 mm standard. Ground pressure? 0.296 kgf/cm² for the UC model. All factory data, no interpretation.

Specifications for the YB401 Series: Engine and Dimensions

The spec page gives you the numbers you need when ordering replacement parts. Engine is a 4-cylinder turbo diesel, water-cooled. Transport length 5180 mm, width 1660 mm, height 2415 mm. Standard bucket capacity 0.11 m³, digging depth 3450 mm. Max digging force 2450 kgf. Travel speed 3.7 and 1.9 km/h. Machine mass 3850 kg for UC, 3450 for UZP. These aren’t optional—knowing your model variant (UC or UZP) changes parts like the boom and cab. If you order a blade assembly without checking the spec, you’ll end up with a part that doesn’t fit.

Parts Identification: Use Factory Figure Numbers

Every assembly gets its own figure. Engine mounts are Fig. 8, radiator and mount Fig. 9, battery and clamp Fig. 38–39, hydraulic pump and coupling Fig. 54. The parts name list (page 3) maps each Japanese label to the figure number. For example, the boom and arm section is Fig. 69, swing cylinder Fig. 52–53, traveling motor Fig. 55. You don’t flip through 188 pages blind—you go straight to the figure for your subsystem. The catalog also calls out optional items like the work lamp (Fig. 84) and heater (Fig. 85–86). If your machine has those, you’ll find the correct part number here, not in a generic aftermarket list.

Paint Codes: Old and New Colors

Yanmar changed the paint scheme in October 1987. The catalog covers both. Old color: Yanmar New Light Yellow (Munsell 10YR6.5/8), Yanmar Cream (2.5Y9/1), Yanmar New Dark Olleve (5GY1/1). New color: Cream White (5.0Y9/1) and Dark Olleve II (7.5GY1/1). Paint codes are listed for 18-liter cans and spray cans. If you’re restoring a machine or touching up a cab, these exact codes let you order the right paint from the dealer. No mixing guesswork. Use Ammann Yanmar B12 B17 Parts Catalog if you need parts for smaller Yanmar crawlers. For older backhoes, check Yanmar Crawler Backhoe YB271 B27 Parts Catalog or the YANMAR Crawler Backhoe Parts Catalog YB301/YB351 Series.

Why OEM Parts Catalogs Beat Aftermarket Diagrams

Aftermarket parts sites compile data from multiple sources—often from scans of old catalogs with missing revisions. This is the third edition (Pub. No. 000 Y 00 K 2042), issued April 1992. It supersedes earlier editions. The parts numbers here are direct from Yanmar’s engineering department, not re-indexed by a third party. When you order a part using the number from this catalog, you get the factory-specified component. The Automotive Industry Overview won’t help you find a fuel line for a Yanmar. Only the OEM catalog has the precise number for the fuel line filter assembly (Fig. 60).

Does this catalog include engine overhaul specs?

No, this is a parts catalog — it lists part numbers and assemblies, not repair procedures.

Can I use this catalog to order parts for a YB401-2 built after 1992?

The third edition covers machine numbers from 20501 onward for the YB401-2, but Yanmar may have released later revisions. Check the machine number against the range listed on page 1. If your serial number is higher, contact the Yanmar dealer to see if there are updated parts. For the YB401, the range starts at 00501. Always verify with the dealer if you’re unsure. The Automotive Industry Overview references general manufacturing standards, but serial number ranges are model-specific.

You’re not going to find a cleaner source for Yanmar YB401 series parts. Every figure, every paint code, every specification came from the factory in 1992. Access the Factory Manual and keep it near your parts washer. You’ll use it every time you tear into one of these machines.