Part of the Yanmar Parts Manuals.
All 178 pages of this Yanmar Crawler Backhoe Parts Catalog (OEM #000Y00K2103) cover the 1986 YB121U and YB151U family: the -2 revisions, Canopy, Cabin, and 3TNA72L-UBVM engine variants. Inside: exploded-view diagrams for every assembly from hydraulic oil piping and control valves to boom, bucket, turning motor, and travel motor, with part numbers cross-referenced across both previous-spec and new-type component revisions. Bucket attachments from 250 to 450mm, standard and wide, are each called out with individual part numbers, pins, shims, and teeth. Electrical assemblies list fuse ratings by position (5A, 10A, and 15A), so you order the right component, not the closest guess. No more hunting through a worn-out parts fiche. Bookmarked by section and keyword-searchable, this PDF puts the correct part number in your hand before you even pick up the phone.
What's Inside This Yanmar YB121U / YB151U Series Parts Manual
| System | Pages | Key Topics |
|---|---|---|
| Electrical System | Wiring Diagram, Battery | |
| Rear Axle, Differential & Brakes | Brake Valve | |
| Hydraulics & 3-Point Hitch | Control Valve, Bucket Cylinder, 3rd Valve Piping | |
| Body & Operator Station | Turning Frame, Bonnet, Seat & Step, Canopy, Cabin, Hyd. Oil Tank | |
| Decals & Accessories | Tool | |
| Other Components | Preface, Specifications, Inlet House & Exhaust Pipe, Electric Part, Control Equipment, Hyd. Oil Piping, Boom & Bucket, Turning Motor, Travel Motor, Bucket 250, Bucket 300, Bucket 350, Bucket 450, Bucket 250W, Bucket 300W, Bucket 350W |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| FUSE | 5A | p. 28 |
Yanmar YB121U / YB151U Series Common Problems This Manual Covers
Yanmar YB121U hydraulic hose part number needed for travel circuit, unsure which fitting type applies p. 97
Check the Hyd. Oil Piping (Travel) exploded view on page 97. Identify your hose by position in the circuit diagram, then match the connector type (elbow, nipple, or tube) against the parts list. Cross-reference your serial number against the Preface on page 1 to confirm Previous vs. New Type spec before ordering.
Manual Section: Hyd. Oil Piping (Travel)Need correct seal kit part number for boom cylinder overhaul, multiple model variants in this manual
Locate the Boom Cylinder Repair/Overhaul exploded view on . Identify the seal set by the cylinder bore dimension shown in the diagram. For YB121U boom and bucket pin/bush cross-reference, check page 106; for YB151U, check page 109. Confirm your model suffix (Previous vs. New Type) on page 1 before placing the order.
Manual Section: Boom Cylinder Repair/OverhaulCorrect fuse ratings and part numbers for electrical panel unclear, canopy versus cabin spec differs p. 30
For Canopy Spec machines, pull the fuse box parts list from page 30. For Cabin Spec, use page 34. Verified fuse ratings are 5A, 10A, and 15A , confirm which position uses which rating by matching the fuse box diagram to your harness layout on the wiring diagram starting at page 5. Order by part number shown in the diagram, not just amperage.
Manual Section: Electric Part (Canopy Spec.)Bucket tooth and pin part numbers needed, not sure which bucket width fits the machine p. 149
Find your bucket size in the Attachment section: 250mm on page 149, 300mm on page 151, 350mm on page 153, or 450mm on page 155. Wide-bucket variants (250W, 300W, 350W, 450W) start at page 157. Each exploded view lists teeth part numbers, side teeth, pins, shims, and grease nipples separately. Match bucket assembly number to your attachment before ordering teeth.
Manual Section: Bucket 250 (Attachment)Travel motor seal kit part number uncertain, previous type versus new type units use different kits p. 145
Identify your travel motor generation first: Previous Type parts are listed on page 145 (includes Seal Kit, Gear, Bearing, and Carrier Kit line items); New Type is on page 147. Check the Preface on page 1 for your serial number range to confirm which generation applies. Order the complete seal kit as a set , individual seal dimensions are not listed separately in this catalog.
Manual Section: Travel Motor (Previous)Control valve section assembly part numbers needed after teardown, swing and boom sections look identical p. 117
Each control valve section has its own exploded view. Swing section parts are on page 117; boom section on page 119. Both use an O-Ring 1B G-55.0 and share similar seal and oil plate components, so verify the Section Assy part number from the correct page before ordering. Cross-check against the Control Valve (P1, P2) list on page 115 if the main stack assembly number is needed.
Manual Section: Control Valve (Swing)Frequently Asked Questions
How do I find the correct part number for a hydraulic hose in the travel circuit?
Check the Hyd. Oil Piping (Travel) exploded view on page 97. Identify your hose by position in the circuit diagram, then match the connector type (elbow, nipple, or tube) against the parts list. Cross-reference the part number with the YB121U or YB151U variant column before ordering.
What seal kit do I need for a boom cylinder overhaul on the YB121U?
Locate the Boom Cylinder Repair/Overhaul exploded view on page 106 (YB121U) or page 109 (YB151U). Identify the seal set by the cylinder bore dimension shown in the diagram. Match the head seal set part number to your specific boom and bucket pin/bush cross-reference on that page.
Which fuse ratings are used in the fuse box and where is the parts list?
For Canopy Spec machines, pull the fuse box parts list from page 30 for Canopy Spec or page 34 for Cabin Spec; match the fuse rating (5A/10A/15A) to your harness using the wiring diagram on page 5, then order by part number.
How do I determine whether my YB121U is a Previous Type or New Type to order the correct cabin or control lever parts?
Check the serial number prefix on page 1 of the catalog. Previous Type and New Type sections are listed separately throughout the parts catalog (e.g., Cabin (Previous) vs Cabin (New Type), Battery (Previous) vs Battery (New Type)). Match your machine serial range to the correct section before ordering any cabin, control equipment, or hydraulic piping parts.
Reviews
There are no reviews yet.