Product name: Komatsu Hydraulic Cylinder Seal Kit
Part No: 144-63-05020 1446305020
Size:65MM / 110MM
Model Number:For D60 D65
Material:Lron+Rubber
Packing:PP bag inside, carton box outside
Payment Terms:Western Union, L/C, T/T, MoneyGram, D/A, D/P
MOQ:Acceptable trial order
Shipping Mode:By air, by sea, by express(Fedex, UPS, DHL, TNT, etc.)
Place of Origin:Guangdong, China
Brand name:COGENG
CertifiCATEEion:ISO9001
Supply :500PCS
Technical Constants & Performance Data
| Parameter | Value / Specification |
|---|---|
| Operating Pressure | Up to 2,500 PSI (172 bar) [Series Design] |
| Temperature Range | -20°F to 200°F (-29°C to 93°C) |
| Fluid Compatibility | Mineral-based hydraulic oils (SAE 10W, AW32/46), Conventional Anti-wear Fluids |
| Primary Seal Material | Polyurethane (AU) & Nitrile Rubber (NBR) – Classic Formulation |
| Seal Hardness (Dynamic) | 88-92 Shore A (Polyurethane) |
| Seal Hardness (Static) | 70 Shore A (NBR O-Rings) |
| Design Standard | Manufactured to original Komatsu D60-1/D65-1 series specifications with modern material upgrades. |
Exact Model Compatibility
| Komatsu Dozer Model | Specific Cylinder Application (Verify) |
|---|---|
| Komatsu D60-1 (All Variants: E, P, PL, S, W) | Likely: Blade Lift, Tilt, or Pitch Cylinders |
| Komatsu D65-1 (All Variants: E, P, S) | Likely: Blade Lift, Tilt, or Pitch Cylinders |
| Note: | This kit is a direct replacement for Komatsu OEM part number 144-63-05020. It is designed for specific cylinders on the listed vintage models. The exact cylinder application must be verified using the machine's original service manual or parts catalog. These part numbers often apply to lift or tilt cylinders. |
Component Specifications Table
| Component Name | Material | Color | Durometer | Function & Note |
|---|---|---|---|---|
| Piston Seal (U-Cup/V-Packing) | Polyurethane (AU) | Brown | 90 Shore A | Primary piston seal; modern PU replaces original leather/cork. |
| Rod Seal (V-Packing Set/Step Seal) | Cast Polyurethane (CU) | Black | 90 Shore A | Rod sealing assembly. Configuration varies by exact cylinder. |
| Wiper/Scraper | Polyurethane (PU) | Black | 85 Shore A | Contaminant exclusion. |
| O-Ring Set (Assorted) | Nitrile Rubber (NBR) | Black | 70 Shore A | Static seals for glands, ports, plugs. |
| Wear Ring / Guide Band | Fabric-Reinforced Phenolic / Nylon | Brown / White | N/A | Piston guidance. Material matches or improves upon original. |
| Backup Washers | Nylon / Leather* | Tan / Brown | N/A | Prevent seal extrusion. (*May include leather for authenticity). |
Installation decomposition diagram

Machine Secure & Pressure Relief: Park the dozer on a firm, level surface. Lower the blade fully to the ground to relieve all hydraulic pressure. Engage the parking brake and block the tracks.
Cleanliness Protocol: Disassembly and assembly must be performed in an impeccably clean, dust-controlled environment. The abrasive nature of dozer work makes contamination control paramount.
Documented Disassembly: Carefully disassemble the tilt cylinder. Photograph and note the exact order and orientation of all components, especially the seal stack in the gland.
Critical Metal Inspection: Use precision tools to inspect the cylinder rod for any scratches, gouges, or corrosion. Check the cylinder bore (ID) for scoring, pitting, or excessive wear. Damaged metal components MUST be replaced prior to seal installation.
Lubricated Assembly: Soak all new elastomeric seals in clean hydraulic fluid. Lightly lubricate all seal grooves and sliding surfaces before installing new seals.
Proper Tool Use: Use seal installation tools (cone tools, picks, sleeves) to carefully install seals without cutting, stretching, or rolling them over sharp edges.
Torque to Specification: During reassembly, use a calibrated torque wrench. Adhere strictly to Komatsu's specified torque values and sequences for gland bolts or end caps.
Critical Specific Warnings
APPLICATION VERIFICATION IS CRITICAL: Part number 707-98-34590 is used for tilt cylinders on specific dozer models. You must verify the exact machine model this kit is designed for using official Komatsu documentation. Using it on an incompatible model or cylinder type will cause failure.
METAL SURFACE CONDITION: This kit seals fluid between precision metal surfaces. It CANNOT repair a scored rod or a worn cylinder bore. Installation on damaged components will result in immediate, severe leakage.
EXTREME ABRASIVE ENVIRONMENT: Dozer tilt cylinders are constantly exposed to dirt. Absolute cleanliness during assembly is non-negotiable to prevent rapid abrasive seal wear upon startup.
BLADE SUPPORT HAZARD: The bulldozer blade must be fully lowered and supported by the ground. Never work on a cylinder that is under load or hydraulic pressure.
Specific Components Included
Complete seal set matching OEM configuration
All dynamic and static seals as specified
Wear components per original design
Necessary backup rings and support components
Note: Kit contents are configured to exactly match the component list and arrangement of the original Komatsu 707-98-41020 kit. Includes detailed installation diagram.
Frequently Asked Questions
A. When will get the items after I place order?
Q. Once your payment is confirmed,we will arrange the goods within 1~4 days; if not in stock, we will inform you before placing the order?
A. If I only know the excavator model, but can not offer parts No.,what should I do ?
Q. If possible, you can send us pictures of old products, nameplate or the size for reference.
A. How can you guarantee the quality??
Q. We will 100% test the goods before delivery. We also support video inspection.
A. How long will it take to delivery to my address??
Q. The normal delivery time is 3-7 days, depending on which country you are in.?
A : Which delivery method will you choose?
Q : By sea, air or express(DHL,Fedex,TNT, UPS, EMS etc.),Sometimes we will arrange as the customer's demand.
A: What's package? Can you give me the package according my requirement??
Q. We usually packed by standard exported box or carton. And yes we can pack as per your requirement.
A: Can the price be cheaper?
Q: Of course, you will be offered a good discount for a big amount.
A: Why should I choose to buy from you?
Q:Our advantages: 100% quality assurance, develop and manufature follow original ones;Quick response within 24 hours; Small order allowed;Reasonable stock and timely delivery;Neutral packing, customized packing are allowed. Positive customer feedback from abroad market;Excellent after-sales service.
A : Which payment terms can you accept?
Q : Paypal. Western Union, Bank Transfer, T/T...
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