Description

Yanmar YB451, YB501 1991 Parts Catalog – Factory Specs for Crawler Backhoe Owners

You have a Yanmar YB451 or YB501 crawler backhoe in the shop, and you need a hydraulic line, a boom pin, or an engine gasket. Grab any aftermarket parts book and you will spend three hours chasing dead ends – wrong numbers, discontinued references, no paint codes that match the machine year. That is why this Yanmar YB451, YB501 1991 Parts Catalog exists. 248 pages of factory-original part numbers, not a reprint of some scanned third-party mess. This is the OEM document that Yanmar issued in November 1991 (Pub. No. 000Y00K2094) covering both domestic and overseas editions. If you want to order parts that fit the first time, this is the only catalog you should trust.

Paint Codes and Color Changes Across Years

Yanmar changed paint formulations in October 1987. The older machines used YANMAR Cream (2.5Y9/1) and YANMAR New Dark Olive (5GY1/1); the newer models from 1987 onward switched to YANMAR Cream White (5.0Y9/1) and YANMAR Dark Olieve II (7.5GY1/1). The catalog lists the exact Munsel numbers and paint codes for 18-liter and spray cans. If you are restoring a YB451 or YB501 and want the correct color for the year, page 1 gives you the code. No guessing. No mixing based on a photo.

Model Variations – YB451, YB501, and the -2 Versions

This catalog doesn’t pretend all machines are the same. It covers YB451, YB501, YB451-2, and YB501-2, with separate machine number ranges for domestic and overseas models. The preface breaks down serial numbers: models from 00501 up, then the March 1988 change at 10501, and finally the -2 series starting at 20501. If you have a YB451-2 with overseas M/# 60501, the catalog shows the correct figure numbers for your country – France gets Fig. 19, Norway gets Fig. 18, Japan might have no figure. You have to know which country edition your machine came from? The catalog tells you exactly how to read the flags.

248 Pages of Factory Part Numbers

Every part is listed with its OEM number, grouped by system – engine, undercarriage, backhoe attachment, hydraulic controls. The specifications page gives engine type (4 TN78TL-D(R)BVM), dimensions, transport length. You don’t get generic dimensions; you get the exact mm lengths for YB451 (5360 mm) and YB501 (5415 mm). The catalog uses figure numbers and country abbreviation tables to route you to the correct illustration. If you need the part for a YB501-2 with a turbo diesel, the page reference will point you to the right figure. No cross-referencing against an aftermarket database that might be wrong.

Why an OEM Parts Catalog Beats Aftermarket Guesswork

Aftermarket parts catalogs often skip supersessions, ignore paint code changes, or merge different machine years into one vague list. This Yanmar document is the genuine 1991 third edition – it supersedes the first edition (1984) and second edition (1987) with a note to discard the old catalogs. That means every discontinued part is either updated or flagged. When you look up a hydraulic seal for a 1991 YB451, the number you get is the number Yanmar currently stocks. I have seen too many techs order a part from a third-party catalog that was obsolete before the machine left the factory. Use the OEM catalog and you avoid that wasted time. For similar machinery, check out the Ammann Yanmar B12 B17 Parts Catalog or the Yanmar YB271, B27 1994 Parts Catalog – OEM Factory Specs if you work on other Yanmar crawler models. There is also the Yanmar YB301 YB351 1991 Parts Catalog – 248 Pages OEM for the next size up.

Who Needs This 1991 Parts Catalog?

If you own a Yanmar YB451 or YB501 – whether the base model or the -2 version – this catalog keeps your parts ordering straight. Shop owners dealing with multiple machines will appreciate having the factory part numbers and paint codes in one place. Home garage enthusiasts restoring a crawler backhoe will finally have the correct part references instead of relying on forum posts and educated guesses. Even if you have the service manual, you still need the parts catalog to identify what bolt, seal, or hose goes where. The automotive industry relies on accurate parts data to avoid downtime – this is the same principle. Read the Automotive Industry Overview to understand the importance of standardized parts documentation.

FAQ – Two Things You Probably Want to Ask

Does this catalog cover the YB451-2 and YB501-2 as well as the original models?

Yes. The catalog explicitly lists model-changed machines from March 1988 and the -2 series. It covers domestic and overseas machine numbers for all four variants.

What about paint codes – are they the same for all years?

No, they changed in October 1987. The catalog gives both the old and new paint colors with Munsel numbers and paint codes. Page 1 has the table. If your machine was built before October 1987, use the old codes; for machines built after that date, use the new codes. The color names changed from “YANMAR Cream” to “YANMAR Cream White” and from “YANMAR New Dark Olive” to “YANMAR Dark Olieve II.” Do not assume the colors are identical – the formulation is different.

Whether you are ordering a hydraulic ram rebuild kit or a decal set, having the correct OEM part number saves hours of cross-referencing. This catalog is the same one Yanmar dealers used in 1991. Automotive Industry Overview can give you broader context, but the concrete spec you need is between these 248 pages. Access the Factory Manual and put the correct part numbers in your hand.