PC40 PC50 Cooling fan blade for excavator engine 4D84/8D88 fan YM129612-44740

YM129612-44740 Cooling Fan Blade for Komatsu PC40 PC50

The YM129612-44740 / YM12961244740 cooling fan blade is used in Komatsu compact excavator engine cooling system applications. It is commonly referenced for Komatsu PC40 and PC50 series machines with 4D84, 4D84E, 4D88 or 4D88E engine references.

This fan blade should be selected by the original part number and physical configuration, not by model name alone. Komatsu compact excavators may vary by engine version, fan hub, blade diameter, mounting hole pattern and rotation direction. Final fitment should be verified before ordering.

Cross Reference Numbers

Common reference numbers may include YM129612-44740 and YM12961244740. Some public references may also mention YM129612-44742 as a related fan blade reference, but it should not be treated as an automatic replacement unless the old fan blade specification confirms the same fitment.

Other fan blade numbers such as 600-635-7850, 600-635-7870, 600-633-7850 or 600-625-0520 should not be mixed into this product page unless they are used only as separate related products.

Application and Fitment Reference

This YM129612-44740 Komatsu cooling fan blade is mainly referenced for compact excavator applications such as PC40, PC40-7, PC40R-7, PC40T-7, PC45R-8, PC50 and PC50UU-2. Some public listings also mention PC50UD-2, PC50UG-2, PC50UUM-2 and PC58SF-1 references.

Engine references may include 4D84, 4D84E, 4D88 and 4D88E. These should be used as fitment references only. Before purchase, compare the old fan blade part number, diameter, blade count, hole count, hub size, offset and rotation direction.

Technical Reference

Some public supplier references list this fan blade with a 440 mm total diameter, 83 mm inner hole diameter and 97 mm hole spacing. These values should be checked against the old fan blade or confirmed by photo measurement before ordering.

Common Failure Symptoms

• Engine overheating: reduced airflow through the radiator may cause high coolant temperature.

• Cracked or broken blade: damaged blades can reduce cooling performance and create imbalance.

• Abnormal vibration: worn mounting points, cracked fan blade or incorrect blade balance may cause vibration.

• Radiator contact marks: incorrect installation, loose mounting or wrong fan specification may cause interference.

• Unusual fan noise: damaged blade edges, loose bolts or shroud interference should be checked.

Troubleshooting Before Replacement

• Check coolant level, radiator cleanliness and fan belt condition before replacing the fan blade.

• Inspect the old fan blade for cracks, deformation, missing sections or worn mounting holes.

• Check the fan hub, pulley, shroud and mounting bolts for damage or looseness.

• Confirm whether overheating is caused by the fan blade, radiator blockage, thermostat, water pump or belt tension.

• Compare the old blade size, hole count and rotation direction before ordering a replacement.

Installation and Maintenance Notes

• Stop the engine and allow the cooling system to cool before removal.

• Inspect the fan hub and mounting surface before installing the replacement blade.

• Do not install a fan blade with a different hole pattern, offset or rotation direction.

• Tighten mounting bolts evenly according to the machine service procedure.

• Check clearance between the fan blade, shroud and radiator before starting the engine.

• After installation, run the engine at low speed first and check for vibration, abnormal noise and airflow direction.

Fitment Check Before Ordering

To reduce wrong orders, please send the machine model, machine serial number, old fan blade part number, full fan blade photo, hub photo, mounting hole photo, blade diameter and rotation direction before quotation.

FAQ

What is the relationship between YM129612-44740 and YM12961244740?

YM12961244740 is the non-hyphen writing format of YM129612-44740. Both formats may appear in parts searches, supplier listings and maintenance records.

Which Komatsu models are commonly listed for this fan blade?

Common model references include Komatsu PC40, PC40-7, PC40R-7, PC40T-7, PC45R-8, PC50 and PC50UU-2. Some public references may also mention PC50UD-2, PC50UG-2, PC50UUM-2 and PC58SF-1. Final fitment should be verified by the old fan blade and machine serial number.

Which engine references are associated with YM129612-44740?

Public references may associate this fan blade with Komatsu or Yanmar engine references such as 4D84, 4D84E, 4D88 and 4D88E. The old fan blade specification should still be compared before ordering.

Can YM129612-44742 replace YM129612-44740?

YM129612-44742 may appear as a related public reference, but it should not be treated as an automatic replacement unless blade diameter, hub size, hole pattern, offset and rotation direction match the original fan blade.

What should be checked before ordering?

Please check the old fan blade part number, blade diameter, blade count, mounting hole count, hub size, offset, rotation direction and machine serial number. Clear photos of the old fan blade are recommended.