Yanmar 3D78-1 3D84-3 Engine Water Pump 129002-42004 129100-42000 129100-42001

Product Details

Product Overview

This premium water pump is specifically designed for Yanmar industrial diesel engines, providing reliable coolant circulation for the 3D78-1 and 3D84-3 engine models. Manufactured to OEM specifications, this replacement pump ensures proper engine temperature regulation and prevents overheating in demanding applications. The part numbers 129002-42004, 129100-42000, and 129100-42001 correspond directly to Yanmar’s original equipment components.

As a critical component of the engine cooling system, this water pump maintains optimal operating temperatures by circulating coolant through the engine block, cylinder head, and radiator. It is commonly used in construction machinery, agricultural equipment, industrial power units, generator sets, marine applications, and material handling equipment powered by Yanmar 3D series engines.

Key Features & Benefits

• OEM-Specification Design: Manufactured to match original Yanmar dimensions and performance characteristics for direct bolt-on replacement
• Precision Engineered Impeller: Cast impeller ensures consistent coolant flow rates matching factory specifications for the 3D78-1 and 3D84-3 engines
• Durable Seal Assembly: High-quality mechanical seal prevents coolant leakage and extends service life in harsh operating environments
• Corrosion-Resistant Housing: Treated casting resists pitting and degradation from coolant additives and operational stress
• Complete Drop-In Replacement: Includes all necessary mounting hardware and gasket for straightforward installation without modifications
• Rigorous Quality Testing: Each unit undergoes pressure testing and rotational balance verification before shipment
• 6-Month Warranty Coverage: Backed by manufacturer warranty providing peace of mind for your equipment investment

Technical Specifications

OEM Cross-Reference

This water pump replaces the following original Yanmar part numbers:

• 129002-42004 – Primary OEM Reference
• 129100-42000 – Alternative OEM Number
• 129100-42001 – Updated OEM Number (supersedes 129100-42000)

Note: Always verify your existing part number before ordering. Cross-reference with your engine’s serial number for guaranteed compatibility.

Compatibility

This water pump is commonly used for the following Yanmar engine models and applications:

• Engine Models: Yanmar 3D78-1, Yanmar 3D84-3
• Common Applications:
  • Construction Equipment (mini excavators, compact loaders)
  • Agricultural Machinery (tractors, harvesters, tillers)
  • Industrial Power Units
  • Generator Sets (gensets)
  • Marine Auxiliary Engines
  • Material Handling Equipment (forklifts, telehandlers)

Fitment Note: While this pump is designed for the specified engine models, we recommend confirming compatibility with your specific equipment make and model before purchase.

Global Supply & Distribution

We maintain extensive inventory levels to support worldwide shipping to industrial buyers, equipment dealers, and repair facilities. Our distribution network covers all major global markets including:

• North America: Rapid delivery to US and Canadian industrial centers via air and sea freight
• Europe: Regular shipments to EU ports including Rotterdam, Hamburg, and Antwerp
• Asia-Pacific: Direct distribution to Japan, South Korea, Australia, and Southeast Asian markets
• Middle East & Africa: Serving Dubai, Saudi Arabia, and major African industrial hubs
• South America: Regular exports to Brazil, Argentina, and Chile

We offer flexible shipping options including express courier (DHL, FedEx, UPS), air freight, and sea freight (FCL/LCL). Our export documentation team ensures full customs compliance for international orders.

Quality Assurance

• Manufacturing Standards: Produced in ISO-certified facilities following strict quality control procedures
• Testing Protocol: Each water pump undergoes:
  • Hydraulic pressure testing to verify seal integrity
  • Rotational balance testing for smooth operation
  • Dimensional verification against OEM specifications
• Warranty: 6-month warranty against manufacturing defects in materials and workmanship
• Inspection: Video outgoing inspection available upon request; machinery test report provided with each shipment

FAQ

Q: How do I confirm this water pump fits my Yanmar 3D78-1 or 3D84-3 engine?
A: Verify your existing water pump part number against our listed OEM numbers (129002-42004, 129100-42000, or 129100-42001). For additional verification, check your engine serial number and consult your equipment’s parts manual. The pump is designed specifically for these engine models but equipment-specific mounting configurations may vary.

Q: What maintenance is recommended when replacing the water pump?
A: We recommend replacing the coolant and thermostat simultaneously when installing a new water pump. Flush the cooling system to remove old debris and deposits. Inspect all coolant hoses for wear and replace if necessary. Use the correct coolant mixture (typically 50/50 antifreeze/water) as specified in your engine manual. Torque mounting bolts to manufacturer specifications.

Q: What is the expected service life of this replacement water pump?
A: Service life depends on operating conditions, maintenance practices, and coolant quality. Under normal operating conditions with proper coolant maintenance, this pump typically provides 2,000-4,000 operating hours of reliable service. Regular inspection of the cooling system and timely replacement of coolant at manufacturer-recommended intervals will maximize pump longevity. Signs of failure include coolant leakage from the weep hole, unusual bearing noise, or engine overheating.