Manufactured to meet or exceed original Komatsu technical specifications
Exact Model Compatibility
Komatsu Part Number
COGENG Replacement
Component Category
707-98-42150
707-98-42150
Hydraulic Cylinder Service Kit
Compatibility Note:
The "707" prefix identifies this kit as belonging to the hydraulic cylinder group, a critical component category for excavators, dozers, and loaders. The exact equipment application must be verified through Komatsu's official parts documentation or Electronic Parts Catalog (EPC) before purchase.
Component Specifications Table
Component Name
Material Specification
Standard
Primary Function
Piston Seal
Premium Polyurethane
ISO 7425-1
Main dynamic pressure seal; maintains pressure between cylinder chambers
Rod Seal
Cast Polyurethane Composite
ISO 6547
Primary rod sealing; prevents hydraulic oil from leaking out of the cylinder
Wiper/Scraper
Heavy-Duty Polyurethane
ISO 6195
Contaminant exclusion; blocks dirt and debris from entering the cylinder
Buffer Seal
Polyurethane (CU)
-
Absorbs pressure spikes and extends rod seal life
Wear Ring/Guide Band
Glass-Filled PTFE
-
Keeps moving parts aligned; prevents metal-to-metal contact
Dust Seal
Polyurethane
-
Secondary contaminant exclusion
O-Ring Set
Nitrile Rubber (NBR)
AS568A/JIS B2401
Static sealing for gland, end cap, ports, and fittings
Backup Rings
Engineering-Grade Nylon
-
Anti-extrusion protection for high-pressure applications
Specific Components Included
Complete seal set matching OEM configuration
All dynamic and static seals as specified
Piston seal(s) – Qty: As per OEM design
Rod seal(s) – Qty: As per OEM design
Wiper/scraper(s) – Qty: As per OEM design
Buffer seal(s) – Qty: As per OEM design
Wear ring(s)/guide band(s) – Qty: As required
Dust seal(s) – Qty: As required
Complete O-ring and backup ring set – Qty: 1 Set
Note: Kit contents are configured to exactly match the component list and arrangement of the original Komatsu 707-98-42150 kit. Each kit is carefully packaged by cylinder type and labeled with model compatibility Support Seals & Hardware
Full complement of seals for complete cylinder rebuild
All required O-rings and backup rings for gland and port assembly
Multi-layer protection system ensuring longer equipment uptime and reduced risk of hydraulic failure -1
Excluded Items: This kit contains seal components only. Piston, rod, barrel, gland, bearings, bolts, and other metal parts are not included.
Installation decomposition diagram
Application Verification: Confirm 707-98-42150 is the correct part number for your specific machine model and cylinder type using official Komatsu documentation.
System Depressurization: Completely relieve all hydraulic pressure before disassembly. Park equipment on level ground and lower all implements fully.
Clean Work Environment: Maintain meticulous cleanliness throughout the repair process. Hydraulic system contamination is a primary cause of seal failure
Documented Disassembly: Carefully disassemble the cylinder. Photograph and note the exact order and orientation of all components, especially the seal stack in the gland.
Component Inspection: Thoroughly inspect all metal components (rod, bore, piston) for wear, scoring, or damage. New seals cannot compensate for worn or damaged metal surfaces.
Proper Installation: Use correct tools and techniques to prevent seal damage during assembly. Lubricate all seals with clean hydraulic fluid before installation.
Torque Compliance: Follow OEM torque specifications for all fasteners.
System Testing: Perform appropriate pressure testing before returning to service to validate seal integrity -
Critical Specific Warnings
APPLICATION VERIFICATION REQUIRED: This kit is designed for specific applications where Komatsu part number 707-98-42150 is specified. Always use the full part number for cross-reference. Using it on incompatible equipment will cause failure.
METAL SURFACE CONDITION: This seal kit cannot compensate for worn or damaged cylinder components. Ensure all metal surfaces are within serviceable limits before installation.
CONTAMINATION CONTROL: Even microscopic debris introduced during assembly will act as an abrasive, destroying new seals. Maintain absolute cleanliness during installation
PRESSURE SAFETY: Always ensure complete system depressurization before beginning any repair work. Compatibility & Application Data
Application Area
Machine Types
Cylinder Applications
Excavators
Komatsu PC Series
Boom, Arm, Bucket Cylinders
Dozers
Komatsu D Series
Blade Lift, Tilt, Angle, Ripper Cylinders
Wheel Loaders
Komatsu WA Series
Lift, Bucket, Steering Cylinders
Quality Standard
Direct OEM Part Number Replacement
Performance equivalent to OEM specifications
Manufacturing
ISO 9001 Quality Systems
Precision material weighing, high-pressure compression molding, rigorous quality inspection
Maintenance Best Practices
Regular Inspections: Frequently check cylinder rods for scratches, pitting, or signs of leakage
Timely Replacement: Replace worn seals promptly to prevent contamination of the entire hydraulic system
Fluid Quality: Use clean hydraulic fluid meeting Komatsu specifications to prolong seal life
Operating Conditions: Monitor pressures and temperatures to prevent extremes that could affect seal performance
Disclaimer: This product is manufactured as an OEM-equivalent replacement part. All manufacturer names, part numbers, and descriptions are used for reference purposes only. COGENG is not affiliated with Komatsu Ltd. For specific application details and installation procedures, always consult the original Komatsu equipment documentation. Specifications subject to change without notice 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...
