| Parameter | Specification |
|---|---|
| Part Number | 707-98-43620 (7079843620) |
| Product Name | Komatsu Tilt Cylinder Repair Seal Kit |
| Supplier / Channel | COGENG (Aftermarket Parts Distributor) - Genuine Komatsu Part |
| Cylinder Type | Tilt Cylinder (Controls bucket angle / blade pitch) |
| Typical Compatible Models | Komatsu WA250-3/5/6, WA320-3/5/6, WA380-3/5/6 (Wheel Loaders) Komatsu D65EX-15/16, D85EX-15 (Dozer Blade Tilt) |
| Cylinder Rod Diameter | 65 mm (Standard for WA320/WA380 Tilt Cylinder) |
| Cylinder Bore Diameter | 125 mm |
| Kit Contents | Dust Seal (Wiper), Rod U-Packing (Main Seal), Buffer Ring, Piston Seal, O-Rings, Backup Rings, Wear Ring |
| Material | NBR, Polyurethane (H-ECOPUR), POM (Polyoxymethylene) Wear Rings |
WARNING: Tilt Cylinder Specific Lockout and Support Hazards
Bucket/Boom Support: The tilt cylinder controls the bucket angle. When removing hoses or pins, the bucket is free to rotate downward with extreme force. NEVER rely on the machine hydraulics to hold the bucket up. ALWAYS install the Bucket Safety Strut / Service Lock or crib the bucket securely on heavy timber blocks.
Pin Extraction Force: Tilt cylinder pins on WA loaders often seize due to lack of grease at the rod eye bushing. DO NOT heat the rod eye cherry red to remove the pin. The heat will travel down the chrome rod and destroy the new 707-98-43620 seals instantly upon first lift. The internal polyurethane melts at 100°C (212°F). Use a Porta-Power hollow cylinder ram to press the pin out cold.
Hydraulic Line Connections: The 707-98-43620 kit is for the cylinder internals. When reinstalling the cylinder, ensure the hose fittings are torqued correctly. Tilt circuit hoses are subject to constant flexing. An undertorqued fitting will leak, spray hot oil onto the operator cab glass, and obscure vision.
Technical Constants & Performance Data
| 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, extrusion resistance, and service life in heavy dozing applications. |
Exact Model Compatibility
| Komatsu Dozer Model | Specific Application |
|---|---|
| Komatsu D68ESS-12 | Blade Tilt (Angle) Cylinders |
| Komatsu D61E-12 | Blade Tilt (Angle) Cylinders |
| Komatsu D61EX-12 | Blade Tilt (Angle) Cylinders |
| Komatsu D61PX-12 | Blade Tilt (Angle) Cylinders |
| Note: | This kit is a direct replacement for Komatsu OEM part number 707-98-43620. It is designed specifically for the TILT/ANGLE CYLINDERS on the listed -12 series dozer models. Verify your machine's model, serial number, and that you are servicing the TILT CYLINDERS, not the lift or ripper cylinders. |
Component Specifications Table
| 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 |
| Gland Seal Set | Nitrile / PTFE Composite | Black/Brown | As specified | Specialized sealing for tilt cylinder gland |
Installation Sequence (English Summary)
Remove Gland: Unscrew head gland from cylinder barrel using a spanner wrench. Do not use a pipe wrench on the threads.
Extract Rod: Pull rod and piston assembly from barrel. Inspect rod for scratches. Tilt cylinders are prone to "bucket dropping" damage; if the rod is dented near the eye, the new 707-98-43620 seals will leak immediately. The rod must be re-chromed or replaced.
Seal Replacement: Follow diagram above. Note that the Buffer Ring (3) sits BELOW (pressurized side) of the Main Rod Seal (2) .
Piston Torque: Komatsu WA320 Tilt Piston Nut requires 2,200 Nm (1,622 ft-lbs) torque and staking. Crucial: Use Loctite 272 (High Temp/High Strength) on the piston nut threads.
Installation decomposition diagram
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.
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.
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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.
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