- CN
| Parameter | Value / Specification |
|---|---|
| Maximum Operating Pressure | Up to 4,350 PSI (300 bar) |
| Temperature Range | -40°F to 225°F (-40°C to 107°C) |
| Fluid Compatibility | Mineral-based hydraulic oils, Komatsu Super Hydraulic Fluid (KSHV), BIO HFDU fluids |
| Primary Seal Material | Polyurethane (AU), Cast Polyurethane (CU), Nitrile Rubber (NBR) |
| Seal Hardness (Dynamic) | 92-95 Shore A (Polyurethane) |
| Seal Hardness (Static) | 70 Shore A (NBR O-Rings) |
| Design Standard | Manufactured to meet or exceed Komatsu's original specifications for pressure holding, wear resistance, and service life. |
| Komatsu Dozer Model | OEM Part Number | Cylinder Application |
|---|---|---|
| Komatsu D61EX-12 | 707-99-43680 | Blade Tilt (Angle) Cylinders |
| Komatsu D61PX-12 | 707-99-43680 | Blade Tilt (Angle) Cylinders |
| Note: | This kit is a direct replacement for Komatsu OEM part number 707-99-43680. It is designed specifically for the TILT/ANGLE CYLINDERS on the D61EX-12 and D61PX-12 dozer models. Verify your machine's model, serial number, and that you are servicing the TILT CYLINDERS, not the lift or ripper cylinders. |
| Component Name | Material | Color | Durometer | Function |
|---|---|---|---|---|
| Main Piston Seal (U-Cup) | Polyurethane (AU) | Brown | 95 Shore A | Primary high-pressure dynamic seal on piston |
| Rod Seal (Step Seal) | Cast Polyurethane (CU) | Black | 94 Shore A | Main rod seal for pressure retention |
| Wiper/Scraper (Heavy-Duty) | Polyurethane (PU) | Black | 92 Shore A | Excludes abrasive dirt, mud, and debris from rod |
| Buffer Ring | Polyurethane (CU) | Black | 92 Shore A | Dampens pressure spikes to protect rod seal |
| O-Ring Kit (Assorted) | Nitrile Rubber (NBR) | Black | 70 Shore A | Static sealing for gland, end cap, and ports |
| Wear Ring / Guide Band | Glass-Filled PTFE | Dark Brown | N/A | Centralizes piston, prevents metal contact |
| Backup Rings | Nylon 6.6 | Tan | N/A | Prevents extrusion of static O-rings under pressure |
| Dust Seal | Polyurethane | Black | 85 Shore A | Secondary contaminant exclusion |
Main Piston Seal (U-Cup) – Qty: 1
Rod Seal (Step Seal) – Qty: 1
Wiper/Scraper (Heavy-Duty) – Qty: 1
Buffer Ring – Qty: 1
Wear Ring (Piston) – Qty: 1
Dust Seal – Qty: As required
Complete O-Ring & Backup Ring Set – Qty: 1 Set (All necessary sizes for gland, port, and fitting assembly)
Note: This kit provides a complete seal profile set designed to match the exact specifications of the original Komatsu 707-99-43680 tilt cylinder kit. An exploded diagram is included for correct assembly.
Full set of precision-molded static O-rings for all gland and port connections
Essential wear guide band to ensure smooth piston travel and minimize side load on seals
High-pressure nylon backup rings for critical O-ring applications
Excluded Items: This is a seal and wear component kit only. It does NOT include the piston, cylinder rod, barrel, gland nut, bearings, bolts, pins, or any other metal parts or hardware.
Machine Secure & Pressure Relief: Park the dozer on firm, level ground. Lower the blade fully to the ground to relieve all hydraulic pressure. Engage the parking brake and block the tracks securely.
Cleanliness Protocol: Disassembly and assembly must be performed in an impeccably clean environment. The abrasive nature of dozer work makes contamination control paramount for seal longevity.
Documented Disassembly: Carefully disassemble the tilt cylinder. Photograph and note the exact order and orientation of all components, especially the complex 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 reconditioned or 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.
System Testing: After assembly, perform a controlled pressure test to validate seal integrity before returning the machine to service.
MODEL-SPECIFIC APPLICATION: This kit is ONLY for the TILT/ANGLE CYLINDERS on Komatsu D61EX-12 and D61PX-12 bulldozers. Do not use on lift cylinders, ripper cylinders, or other dozer models without verification. Incorrect application will cause immediate seal 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 and loss of blade control.
EXTREME ABRASIVE ENVIRONMENT: Dozer tilt cylinders are constantly exposed to dirt and debris. Absolute cleanliness during assembly is non-negotiable to prevent rapid abrasive seal wear upon startup.
CONTAMINATION CONTROL: Even microscopic debris introduced during assembly will act as grinding paste, destroying new seals within hours of operation. Maintain surgical cleanliness throughout the repair process.
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.
| Application Sector | Target Equipment | Cylinder Type | Symptoms Addressed |
|---|---|---|---|
| Heavy Earthmoving & Grading | Komatsu D61EX-12 / D61PX-12 Dozers | Blade Tilt/Angle Control | Inability to hold blade angle ("drift"), visible hydraulic oil leakage from the rod gland, slow or weak blade tilt response, oil pooling under the machine |
| Construction & Site Development | -12 Series Dozer Blade Hydraulics | Tilt Cylinder Rebuild | Loss of precise grading control, "loose" or unresponsive blade feel, increased hydraulic fluid consumption |
| Mining & Quarry Operations | Dozer Blade Angle/Tilt Systems | Hydraulic Implement Repair | Reduced equipment productivity, increased maintenance costs, unplanned downtime due to hydraulic failure |
| Equipment Maintenance | Scheduled Overhauls & Leak Repair | Tilt Cylinder Service Kit | Restores factory sealing for reliable blade control, prevents costly environmental fluid loss, cost-effective OEM alternative |
Maintenance Best Practices:
Regular Inspections: Frequently check tilt 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 D61EX-12/D61PX-12 service 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...
