CAT D6T,D6T XL,D6T XW,D6T LGP,D6T LGPPAT Piston Pump | Part No. 4448539 (444-8539)

CAT 4448539 (444-8539) Piston Pump | Fits D6T D6T XL D6T XW D6T LGP Bulldozer

Premium hydraulic piston pump designed as a direct OEM-compatible replacement for Caterpillar D6T, D6T XL, D6T XW, D6T LGP, and D6T LGPPAT track-type tractors. Built to deliver consistent hydraulic power and long service life in demanding earthmoving, mining, and land clearing applications.

Product Highlights

• Part Number: 4448539 / 444-8539
• Direct Fit: No modifications required
• High Performance: Meets or exceeds original Caterpillar specifications
• Durable Construction: Precision-engineered for long service life
• Wide Application: Suitable for earthmoving, mining, and land clearing projects

Technical Specifications

• Part Number: 4448539 / 444-8539
• Product Type: Variable Displacement Piston Pump
• Brand Compatibility: Caterpillar (CAT)
• Application: Hydraulic System
• Warranty: 12 Months

Compatible Models

This piston pump fits the following Caterpillar bulldozer models:

• Caterpillar D6T Track-Type Tractor
• Caterpillar D6T XL Track-Type Tractor
• Caterpillar D6T XW Track-Type Tractor
• Caterpillar D6T LGP Track-Type Tractor
• Caterpillar D6T LGPPAT Track-Type Tractor

Applications

• Main Hydraulic Pump Replacement
• Blade and Ripper Circuits
• Steering and Travel Systems
• Earthmoving, Mining, and Land Clearing Projects

Why Choose This Pump?

• Quality Guaranteed - Manufactured to meet OEM standards
• Ready to Ship - In stock and available for immediate dispatch
• Expert Support - Technical assistance available
• Competitive Pricing - Cost-effective alternative to dealer parts

Frequently Asked Questions

Q: What are the symptoms of a failing hydraulic piston pump on CAT D6T, D6T XL, D6T XW, D6T LGP, or D6T LGPPAT bulldozers?
A: Common signs include slow or weak blade lift and tilt response, the blade hesitating or failing to hold position under load, hydraulic oil overheating during extended dozing operations, whining or knocking noise from the pump area, and visible hydraulic fluid leakage. The D6T series are medium track-type tractors used in earthmoving, mining, and land clearing — pump failure causes loss of blade control and reduced dozing efficiency.

Q: Does the 4448539 fit all five D6T bulldozer variants?
A: Yes, the 4448539 (444-8539) is designed as a direct OEM-compatible replacement for the CAT D6T, D6T XL, D6T XW, D6T LGP, and D6T LGPPAT track-type tractors. These models share the same pump mounting and hydraulic system architecture. Contact us with your bulldozer serial number to confirm exact compatibility.

Q: What hydraulic functions does this pump support on a D6T bulldozer?
A: As the main hydraulic pump, it supplies flow to the blade lift and tilt circuits, ripper functions, steering and travel systems, and any auxiliary hydraulic circuits. Precise blade control is critical for grading and earthmoving work — a failing pump causes the blade to drift, hesitate, or lose position accuracy, directly affecting work quality and productivity.

Q: Should I flush the hydraulic system when replacing this pump on a D6T bulldozer?
A: Always. Bulldozers operate in extremely high-contamination environments (earthmoving, land clearing, mining). Metal particles and environmental contaminants from the old pump can destroy the new pump within hours. Drain and replace all hydraulic oil, flush the system thoroughly with clean oil, replace all filters, and refill with fresh Cat HYDO Advanced hydraulic oil.

Q: What type of hydraulic oil is recommended for the D6T series bulldozers?
A: Caterpillar specifies Cat HYDO Advanced 10W or 30W depending on ambient operating temperature. D6T bulldozers in earthmoving and mining applications operate under sustained heavy load — using non-CAT approved hydraulic fluids can cause accelerated pump wear, loss of blade control accuracy, and void the warranty.

Q: How do I confirm this is the correct pump for my D6T bulldozer?
A: Check the part number on your current hydraulic pump — if it reads 4448539 or 444-8539, this is the correct replacement. If the label is worn or missing (common in earthmoving environments), provide your D6T serial number and we will verify compatibility before you order.

Q: Does this pump come with mounting hardware or gaskets included?
A: The pump is supplied as a complete unit. Depending on your bulldozer configuration, you may need separate mounting bolts, gaskets, or O-rings. Contact us with your serial number and we will confirm exactly what is included and what additional parts you may need for installation.

Q: What is the warranty on this hydraulic piston pump?
A: This piston pump comes with a 12-month warranty covering manufacturing defects. The warranty does not cover damage caused by contaminated hydraulic oil, improper installation, failure to flush the hydraulic system, or using non-CAT approved hydraulic fluids.

Looking for this hydraulic pump? Contact us today for pricing, availability, and lead time information.

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