Document Version: 1.0
Date of Issue: October 26, 2023
Product Category: Hydraulic Components / Motor Grader Spare Parts
Brand: COGENG
Manufacturer Reference: Komatsu OEM Reference
Application: Steering Cylinder Seal Kit
This document serves as the comprehensive technical specification for the hydraulic seal kit identified by part number 707-98-14030 (also formatted as 7079814030), supplied by COGENG. This part is a critical component within the steering hydraulic system of the Komatsu GD825A Motor Grader, specifically designed to restore and maintain the performance of the steering cylinder.
The purpose of this document is to provide engineers, mechanics, procurement specialists, and maintenance teams with a complete understanding of the physical specifications, compatibility, installation protocols, and maintenance requirements for this specific seal kit.
The 707-98-14030 is a precision-engineered Steering Cylinder Seal Kit manufactured by COGENG for the Komatsu GD825A Motor Grader. This kit contains all necessary seals, O-rings, backup rings, and wear rings required to rebuild the steering cylinder, restoring its ability to convert hydraulic pressure into precise steering movement.
The steering cylinder is one of the most critical safety components on a motor grader. It controls the direction of the front wheels, allowing the operator to steer the machine accurately during grading, ditching, and road maintenance operations. A leaking or worn steering cylinder can lead to loss of steering control, posing significant safety risks. This seal kit is essential for restoring the steering cylinder to like-new condition.
The sealing components are manufactured from high-grade materials such as NBR (Nitrile Butadiene Rubber), PTFE (Polytetrafluoroethylene), and polyurethane (PU) to ensure long service life and reliable sealing performance under the demanding conditions of motor grader operation.
Key Functional Characteristics:
Complete Sealing Solution: Contains all seals required for a full steering cylinder rebuild.
High-Pressure Capability: Designed to withstand operating pressures up to 350 bar.
Chemical Resistance: Seals are resistant to hydraulic oil, water, and common contaminants.
Temperature Resistance: Suitable for operating temperatures ranging from -20°C to +100°C.
Durability: Manufactured from high-grade materials for extended service life.
COGENG Quality: Manufactured to meet or exceed OEM specifications.
Complete Kit: Includes rod seal, buffer seal, dust wiper, piston seal, wear rings, O-rings, and backup rings.
Precision Manufacturing: All seals are manufactured to exacting tolerances for perfect fit.
Material Excellence: Utilizes NBR, PTFE, and PU materials for optimal performance.
Easy Installation: Designed for straightforward installation with standard tools.
OEM Quality: Manufactured to meet or exceed Komatsu OEM specifications.
Chemical Resistance: Resistant to hydraulic oil, water, and common contaminants.
Temperature Resistance: Suitable for operating temperatures ranging from -20°C to +100°C.
Steering-Specific Design: Engineered specifically for the steering cylinder application on the GD825A.
The following list details the components included in the 707-98-14030 seal kit. This part number refers to a complete Steering Cylinder Seal Kit. The breakdown below represents the internal structure of the kit.
| Item No. | Part Number | Description | Quantity | Material |
|---|---|---|---|---|
| 1 | 707-98-14030 | Steering Cylinder Seal Kit | 1 | Various |
| 2 | 707-98-14031 | Rod Seal | 1 | PU / NBR |
| 3 | 707-98-14032 | Buffer Seal | 1 | PU |
| 4 | 707-98-14033 | Dust Wiper Seal | 1 | PU |
| 5 | 707-98-14034 | Piston Seal | 1 | PTFE / NBR |
| 6 | 707-98-14035 | Wear Ring (Rod) | 1 | PTFE |
| 7 | 707-98-14036 | Wear Ring (Piston) | 2 | PTFE |
| 8 | 707-98-14037 | O-Ring (Piston) | 1 | NBR |
| 9 | 707-98-14038 | Backup Ring (Piston) | 2 | PTFE |
| 10 | 707-98-14039 | O-Ring (Cylinder Head) | 1 | NBR |
| 11 | 707-98-14040 | Backup Ring (Cylinder Head) | 1 | PTFE |
| 12 | 707-98-14041 | O-Ring (Cylinder Tube) | 1 | NBR |
| 13 | 707-98-14042 | Backup Ring (Cylinder Tube) | 1 | PTFE |
| 14 | 707-98-14043 | Piston Nut Seal | 1 | NBR |
| 15 | 707-98-14044 | Cushion Seal | 1 | NBR |
| 16 | 707-98-14045 | Check Valve Seal | 1 | NBR |
Note: The specific quantities and part numbers of individual seals may vary slightly based on the specific production batch. Always verify with the serial number of your machine.
For maintenance purposes, the following items are recommended to be kept in stock:
Complete Seal Kit: The 707-98-14030 kit itself.
Hydraulic Oil: ISO VG 46 anti-wear hydraulic oil.
Filter Element: Return filter and suction filter.
Steering Cylinder Rod: In case of rod damage during disassembly.
Steering Cylinder Tube: In case of tube damage during disassembly.
The part number 707-98-14030 is primarily designed for the Komatsu GD825A Motor Grader. However, due to cross-manufacturing and shared platform designs, it may also fit certain models from other brands.
This part is most commonly found on the following machine models:
Komatsu GD825A-2 (Motor Grader)
Komatsu GD825A-3 (Motor Grader)
Komatsu GD825A-4 (Motor Grader)
Komatsu GD825A-5 (Motor Grader)
When searching for this part, you may encounter the following interchangeable or superseded part numbers. If you cannot find 707-98-14030, check for these:
707-98-14020
707-98-14021
707-98-14022
707-98-14023
707-98-14024
707-98-14025
707-98-14026
707-98-14027
707-98-14028
707-98-14029
Warning: While these numbers are often interchangeable, the specific suffix number usually denotes a specific revision or a different cylinder size. It is crucial to confirm the exact cylinder dimensions before ordering.
Installing a steering cylinder seal kit is a precision operation. Failure to follow these precautions can result in immediate damage to the seals, hydraulic contamination, or loss of steering control.
Verify Part Number: Ensure the new seal kit matches the old seal kit exactly. Check the dimensions of all seals.
Cleanliness: The hydraulic system is highly sensitive to contamination. Clean the area around the steering cylinder before disassembly.
Hydraulic Oil: Check the hydraulic tank for debris or metallic particles. If the old cylinder failed catastrophically, the entire hydraulic system must be flushed.
Inspect Mating Parts: Check the steering cylinder rod for scratches, dents, or excessive wear. Check the cylinder tube for scoring or damage.
Check Steering Linkage: Inspect the steering linkage, tie rods, and king pins for wear or damage.
Safety First: Ensure the machine is parked on level ground, the engine is off, and the hydraulic system is depressurized before beginning work.
Disassembly: Carefully disassemble the steering cylinder. Use proper tools to avoid damaging the rod or tube.
Cleaning: Thoroughly clean all metal components with a suitable solvent. Dry with compressed air.
Inspection: Inspect all metal components for wear, cracks, or damage. Replace any damaged components.
Seal Installation: Install the new seals in the correct orientation. Use a seal installation tool or a blunt object to avoid damaging the seals.
Lubrication: Lubricate all seals with clean hydraulic oil before assembly.
Assembly: Carefully reassemble the cylinder. Tighten the cylinder head bolts to the specified torque.
This is the most critical step.
Fill Casing: Before connecting the hydraulic hoses, fill the cylinder with clean hydraulic oil.
Air Bleeding:
Start the engine at low idle.
Slowly operate the steering in both directions to circulate oil.
Loosen the hose fitting slightly to allow air to escape until oil flows out, then tighten.
Check for Leaks: Inspect all connections for leaks while the system is under pressure.
Steering Test: Slowly turn the steering wheel from lock to lock to ensure proper operation. Check for any hesitation, noise, or binding.
Final Check: Check the hydraulic oil level in the tank and top up if necessary.
Crush Hazard: The steering cylinder is heavy. Ensure proper lifting equipment is used.
High Pressure: Hydraulic fluid under pressure can penetrate the skin. Relieve pressure before disconnecting lines.
Hot Oil: Allow the system to cool before servicing.
Pinch Points: Keep hands and fingers away from moving parts during installation.
Steering Safety: Never operate the machine with a known steering cylinder leak. Loss of steering can cause serious injury or death.
Support the Machine: If the steering cylinder removal requires the front wheels to be raised, ensure the machine is properly supported with jack stands.
This section provides a detailed breakdown of the equipment compatible with the 707-98-14030, including specific model years and regional variations.
The 707-98 series seal kit is the standard steering cylinder seal kit for the Komatsu GD825A Motor Grader. This machine is a heavy-duty motor grader used in mining, road construction, and large-scale earthmoving operations.
Komatsu GD825A-2: Produced in the late 1990s to early 2000s. This model is known for its reliability and is widely used in mining and road maintenance. The 707-98-14030 is a direct fit for the steering cylinder seal kit.
Komatsu GD825A-3: Updated version of the GD825A. The seal kit specification remains consistent.
Komatsu GD825A-4: Later generation GD825A. The 707-98-14030 is compatible.
Komatsu GD825A-5: The most recent generation of the GD825A. Always verify by serial number.
Komatsu GD655: Some models may share steering cylinder components. Verification required.
Komatsu GD675: Some models may share steering cylinder components. Verification required.
Komatsu GD755: Some models may share steering cylinder components. Verification required.
Komatsu GD825: Earlier generation motor grader. Verification required.
To ensure compatibility with your specific machine:
Locate the Serial Number: Find the machine's serial number plate (usually in the cab).
Check the Parts Manual: Consult the official Komatsu parts manual for your specific serial number range.
Visual Inspection: Compare the old seals with the new seals. Check the dimensions (inner diameter, outer diameter, thickness) of all seals.
Measure the Cylinder: Measure the bore diameter and rod diameter of the steering cylinder to confirm the seal kit size.
Check the Steering Cylinder Part Number: The steering cylinder itself may have a part number stamped on it. Cross-reference this number to confirm compatibility.
Q1: What is the part number 707-98-14030 exactly?
A: The 707-98-14030 is a Steering Cylinder Seal Kit manufactured by COGENG for the Komatsu GD825A Motor Grader. It contains all the seals required to rebuild the steering cylinder.
Q2: Can I replace just the seals without replacing the cylinder?
A: Yes, provided the steering cylinder rod and tube are in good condition. If the rod is scratched or the tube is scored, the cylinder should be replaced or repaired.
Q3: Why does my steering cylinder leak?
A: Leaking can be caused by:
Worn seals: Replace the seal kit.
Damaged rod: Replace or repair the rod.
Scored tube: Replace or repair the tube.
Contaminated oil: Flush the system and replace the oil.
Excessive steering pressure: Check the steering relief valve.
Q4: What is the warranty period for this part?
A: Standard warranty for these hydraulic components is typically 6 to 12 months, depending on the supplier. However, warranty is void if the unit is disassembled, if the system was not flushed after a previous failure, or if the wrong hydraulic oil was used.
Q5: How do I know if my steering cylinder is a two-speed or single-speed unit?
A: Steering cylinders are not classified as two-speed or single-speed. This classification applies to travel motors. Steering cylinders are classified by bore diameter, rod diameter, and stroke length.
Q6: Can I use this seal kit on a different brand of motor grader?
A: It is not recommended unless you are a qualified hydraulic engineer. While the seals might physically fit, the dimensions may not match the host machine's cylinder, leading to poor performance or failure.
Q7: What type of hydraulic oil should I use?
A: Always use the oil specified by the equipment manufacturer. Typically, this is an ISO VG 46 anti-wear hydraulic oil. Using the wrong viscosity can cause overheating and internal damage.
Q8: Do I need to replace the hydraulic filter after installing a new seal kit?
A: Yes. It is highly recommended to replace the return filter and the suction filter immediately after installation. If the old cylinder failed, the system should be flushed with a flushing fluid, and the filters replaced again after 50 hours of operation.
Q9: What is the typical lead time for this part?
A: Lead times vary. Standard stock items may ship within 24-48 hours. Custom or non-stock items may take 15-30 days for manufacturing or sourcing.
Q10: How do I identify if I have a genuine OEM part or an aftermarket replacement?
A: Genuine OEM parts will have the Komatsu logo and part number cast or stamped into the metal. Aftermarket parts may have the part number but lack the logo. COGENG parts are aftermarket replacements manufactured to meet or exceed OEM specifications. Always source from a trusted supplier.
Q11: What is the difference between 707-98-14030 and other 707-98 numbers?
A: The base number "707-98" indicates the series. The suffix (e.g., -14030) indicates the specific revision, configuration, or cylinder size. Always match the complete part number.
Q12: Can I rebuild the steering cylinder instead of replacing it?
A: Yes, steering cylinders are rebuildable. However, it requires specialized tools, a clean environment, and technical expertise. Rebuilding is often more cost-effective than replacement if the core is in good condition.
Q13: How do I know if my steering cylinder is bad?
A: Signs of a bad steering cylinder include:
Steering drift: The machine pulls to one side.
Loss of steering power: Difficulty turning the wheel.
Visible leaks: Hydraulic oil around the cylinder.
Noisy steering: Whining or groaning sounds.
Excessive play: The steering wheel has excessive free play.
Q14: Can I replace the steering cylinder seal kit myself?
A: Yes, if you have mechanical experience and the proper tools. However, steering is a critical safety system. If you are unsure, consult a qualified mechanic.
Q15: What is the difference between a steering cylinder seal kit and a boom cylinder seal kit?
A: Both are hydraulic cylinder seal kits, but they are designed for different cylinders with different dimensions. The steering cylinder seal kit is specifically sized for the steering cylinder on the GD825A.
| Parameter | Specification |
|---|---|
| Part Number | 707-98-14030 (7079814030) |
| Brand | COGENG |
| Type | Steering Cylinder Seal Kit |
| Series | 707-98 |
| Material | NBR, PTFE, PU |
| Max Pressure | 350 bar (Operating) / 400 bar (Peak) |
| Temperature Range | -20°C to +100°C |
| Oil Type | ISO VG 46 Anti-Wear Hydraulic Oil |
| Weight | Approx. 0.5-1.0 kg (Complete Kit) |
| Application | Steering Cylinder — Komatsu GD825A |
| Certification | ISO 9001 |
| Country of Origin | China (Aftermarket) |
| Compatibility | Komatsu GD825A Motor Grader |
We offer worldwide shipping for all our hydraulic components and spare parts. Our shipping partners include DHL, FedEx, UPS, and EMS to ensure fast and reliable delivery.
Shipping Methods:
Express Shipping: 3-7 business days for urgent orders.
Standard Shipping: 7-15 business days for regular orders.
Economy Shipping: 15-30 business days for bulk orders.
Shipping Costs:
Shipping costs are calculated based on the weight, dimensions, and destination of the package.
For bulk orders, please contact us for a customized shipping quote.
Packaging:
All parts are carefully packaged in protective materials to prevent damage during transit.
Each package is labeled with the part number and quantity for easy identification.
Tracking:
Once your order is shipped, you will receive a tracking number via email.
You can track your order on the carrier's website.
We are committed to ensuring your satisfaction with our products. If you are not completely satisfied with your purchase, we offer a hassle-free return policy.
Return Eligibility:
Returns are accepted within 30 days of delivery.
The item must be unused, in its original packaging, and in the same condition as received.
A valid proof of purchase (order number or receipt) is required.
Non-Returnable Items:
Custom-made or special-order parts.
Parts that have been installed or used.
Parts that have been damaged due to improper installation or handling.
Return Process:
Contact our customer service team to request a return authorization (RA) number.
Pack the item securely in its original packaging.
Ship the item back to the address provided by our customer service team.
Once we receive and inspect the item, we will process your refund or exchange.
Refunds:
Refunds will be processed within 5-7 business days after we receive the returned item.
Refunds will be issued to the original payment method.
Shipping costs are non-refundable unless the return is due to our error.
Exchanges:
If you need to exchange an item, please contact our customer service team.
Exchanges are subject to product availability.
Identify Your Part Number: Use your machine's parts manual or contact us for assistance.
Request a Quote: Send us an email or WhatsApp message with the part number and quantity.
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Shipping and logistics inquiries.
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End of Document
Disclaimer: This document is for informational purposes only. The manufacturer reserves the right to change specifications without notice. Always consult the official service manual for your specific machine before performing any repairs. Part numbers and compatibility are based on industry cross-reference data and may vary by region and production year. COGENG is an aftermarket supplier and is not affiliated with Komatsu.
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