The COGENG 707-52-10700 Cylinder Seal Kit is a premium-grade, OEM-replacement sealing solution meticulously engineered for Komatsu hydraulic excavators. This comprehensive kit contains all the precision-molded polyurethane, nitrile rubber (NBR), and polytetrafluoroethylene (PTFE) components required to completely rebuild a hydraulic cylinder, restoring it to factory-fresh sealing performance. Designed to fit a wide range of Komatsu models, this seal kit effectively eliminates internal and external leaks, reduces cylinder drift, and restores full operating pressure – ensuring your excavator's hydraulic system performs with maximum efficiency and reliability.
Hydraulic cylinder leakage is one of the leading causes of productivity loss in heavy equipment. Worn seals allow pressurized oil to bypass the piston, resulting in sluggish boom, arm, and bucket movements, increased fuel consumption, and premature pump wear. The COGENG 707-52-10700 kit addresses these issues with a complete set of components that meet or exceed Komatsu's original dimensional and material specifications. Each seal is manufactured using advanced injection-molding and compression-molding techniques, with tight tolerances maintained through 100% in-process gauging. The polyurethane rod seals offer exceptional abrasion resistance and low friction, while the PTFE anti-extrusion rings provide stability under extreme pressures up to 35 MPa (5,000 psi). The nitrile rubber O-rings and backup rings ensure reliable static sealing even under wide temperature fluctuations.
This kit is the preferred choice for workshop rebuilds, field overhauls, and preventive maintenance programs. By choosing COGENG, you are not just replacing worn parts – you are investing in a sealing system that extends cylinder service life, reduces oil contamination from seal debris, and minimizes unplanned downtime. Each kit is carefully packed to prevent damage during transit, with individual components segregated and labeled for hassle-free identification during installation.
| Figure | Description |
|---|---|
| Figure 1 | Complete kit overview – Top-down layout photograph showing every component of the 707-52-10700 kit arranged in logical groups: rod seals, piston seals, wiper seals, O-rings, backup rings, and wear guides. |
| Figure 2 | Rod seal cross-section – Detailed diagram illustrating the urethane sealing lip profile and its dynamic interaction with the chrome-plated cylinder rod surface during extension and retraction cycles. |
| Figure 3 | Piston seal assembly – Exploded view of the piston area, showing how the double-acting seal rings, O-rings, and anti-extrusion rings assemble onto the piston groove. |
| Figure 4 | Wiper (scraper) seal close-up – Highlights the unique lip design that removes dirt, dust, and moisture from the rod as it retracts, preventing external contaminants from entering the hydraulic system. |
| Figure 5 | Cylinder bore orientation – Cutaway schematic indicating the exact placement of each seal within the cylinder barrel, piston, and gland (head) assembly. |
| Figure 6 | Color-coded component guide – Reference chart matching each seal to its corresponding groove location in the cylinder, with dimensions noted for verification against old parts. |
| Figure 7 | Wear guide (bearing ring) – Shows the fabric-reinforced phenolic bearing ring that supports the piston and rod, reducing metal-to-metal contact and extending cylinder life. |
| Figure 8 | Installation sequence infographic – Step-by-step visual guide showing the correct order of assembly, with caution points marked for sharp edges that could damage new seals. |
The COGENG 707-52-10700 Cylinder Seal Kit is compatible with a broad range of Komatsu hydraulic excavators, particularly those used in mid-size to large-class applications. This kit is designed to fit standard boom, arm, and bucket cylinders with a specific bore and rod diameter configuration. Always confirm your cylinder's dimensions and part numbers before ordering.
| Komatsu Model | Typical Cylinder Application | Remarks |
|---|---|---|
| PC200-5 / -6 / -7 | Boom cylinder, Arm cylinder | Direct fit for standard cylinders |
| PC210-5 / -6 / -7 | Bucket cylinder, Boom cylinder | Confirm serial number range |
| PC220-5 / -6 / -7 | Arm cylinder, Attachment cylinder | Also fits some tilt cylinders |
| PC240LC-6 / -7 | Boom cylinder (heavy-lift variant) | Verify rod diameter (standard vs. optional) |
| PC270-7 | Arm cylinder | Cross-compatible with certain PC240 cylinders |
| PC300-5 / -6 | Bucket cylinder (partial compatibility) | Confirm bore size matches |
| PC360-6 / -7 | Boom cylinder (limited – check serial prefix) | Refer to compatibility notes below |
| PC400-5 / -6 | Arm cylinder (specific production dates) | Use only after dimensional verification |
Note: This kit is primarily designed for standard Komatsu cylinders with a nominal bore diameter of approximately 100–120 mm and rod diameter of 60–70 mm. For machines with larger or smaller cylinders, please contact COGENG with your cylinder serial number for exact cross-referencing.
Installation Steps (Visual Summary):
Safe disassembly – Position the cylinder on a clean, flat workbench. Relieve all hydraulic pressure and drain oil into a suitable container. Remove the cylinder head gland using a spanner wrench or pin wrench.
Extract piston rod – Carefully pull the rod and piston assembly from the barrel. Support the rod evenly to prevent scratching the chrome surface.
Disassemble components – Remove the gland, piston, and all old seals. Clean every groove and surface with a non-abrasive solvent. Inspect the bore and rod for scoring, pitting, or out-of-round conditions.
Inspect wear guides – Check the old bearing rings for excessive wear; replace all items from the COGENG kit regardless of apparent condition.
Install new piston seals – Fit the O-ring into the piston groove, then install the PTFE backup ring on each side. Apply a thin film of clean hydraulic oil to all seals before assembly.
Install new rod seals and wiper – Into the clean gland housing, install the U-cup rod seal (lip facing inward toward the pressure chamber), followed by the O-ring and backup ring. Finally, press the wiper seal into the outer gland groove (lip facing outward).
Assemble piston to rod – Slide the piston onto the rod and torque the retaining nut to manufacturer specifications (refer to machine service manual).
Reinsert assembly – Guide the piston and rod assembly carefully back into the cylinder barrel, taking care not to nick the new seals on thread ends or port edges. Use a seal installation sleeve if available.
Reinstall gland – Thread the gland onto the barrel or into the rod, depending on cylinder design, and torque to spec.
Function test – After full assembly and installation on the machine, cycle the cylinder slowly for 5–10 full strokes to purge air and allow seals to seat. Check for external leakage around the gland.
| Important Consideration | Detail |
|---|---|
| OEM Cross Reference | Direct replacement for Komatsu genuine part number 707-52-10700. Also supersedes 707-52-10701 and certain 707-52-10xxx series kits. Always compare with your old kit's contents. |
| Cylinder Bore Range | Designed for cylinders with bore diameters from 100 mm to 125 mm (3.94"–4.92"). Measure your cylinder bore before ordering to confirm fitment. |
| Rod Diameter Range | Suitable for rod diameters of 60 mm, 65 mm, or 70 mm (2.36", 2.56", 2.76") depending on the specific kit variant – verify your rod size. |
| Pressure Rating | Seals are rated for continuous operation at 34.3 MPa (4,970 psi) and intermittent peaks up to 39.2 MPa (5,680 psi). |
| Temperature Range | Operating range: –40 °C to +110 °C (–40 °F to +230 °F). For extreme cold or high-heat applications (e.g., steel mills), contact COGENG for special material options. |
| Fluid Compatibility | Compatible with standard petroleum-based hydraulic oils (ISO VG 32, 46, 68) and biodegradable fluids (HEES, HETG). Not recommended for water-glycol or phosphate-ester fluids without prior validation. |
| Surface Finish Requirement | For optimal seal life, the cylinder bore should have a surface finish of Ra 0.2–0.4 µm and the rod a finish of Ra 0.1–0.3 µm. Rough or scratched surfaces will void seal performance. |
| Storage Life | 4 years when stored in original packaging, away from ozone, UV light, and temperatures above 40 °C. |
| Installation Lubrication | Use clean hydraulic oil or a dedicated assembly grease (e.g., Kluber) – never use petroleum jelly or molybdenum disulfide, which can cause swelling. |
| Shipping Detail | Description |
|---|---|
| Shipping Methods | By Air, By Sea, By Express (FedEx, UPS, DHL, TNT, etc.). The specific arrangement will be based on the cargo situation and destination. |
| Estimated Delivery Time | Based on the shipping time of the logistics company. The arrival time shown by the carrier's tracking system shall prevail. |
| Packing | Inner: Sealed anti-static plastic bag with desiccant. Outer: Reinforced 5-layer corrugated carton box with foam-in-place cushioning. Individual seals are separated by partition cards to prevent abrasion. |
| Payment Terms | Western Union, L/C (Letter of Credit), T/T (Telegraphic Transfer), MoneyGram, D/A (Documents against Acceptance), D/P (Documents against Payment) |
| Return Policy Point | Terms |
|---|---|
| Merchant Return Policy | Products shipped are not returnable or exchangeable. |
| Quality Guarantee | Every seal kit is 100% inspected for dimensional accuracy, hardness (Shore A), and tensile strength before packing. A batch test certificate is available on request. Our rigorous QA process ensures zero DOA (Dead on Arrival) components. |
| Pre-Shipment Confirmation | Photos and testing videos can be provided upon request before shipment to confirm correct part numbers and operational condition. We highly recommend providing your cylinder serial number for positive cross-reference. |
Q1: What is included in the COGENG 707-52-10700 seal kit?
A: This comprehensive kit includes rod seal (U-cup), piston seal rings (standard double-acting type), wiper seal (scraper), all necessary O-rings, PTFE backup rings, and fabric-reinforced wear guides (bearing rings). The exact part count varies slightly by cylinder design – contact us for a detailed component list specific to your cylinder.
Q2: How do I confirm if this kit fits my Komatsu PC210?
A: Check the identification tag on your cylinder (usually stamped on the barrel or gland). If the part number matches 707-52-10700 or you have a bore diameter of 110 mm and rod diameter of 65 mm, this kit is correct. Alternatively, send us photos of your old seals with measurements for verification.
Q3: Can I use this kit on a cylinder with a scratched rod?
A: No – a scratched or pitted chrome rod will quickly damage the new rod seal and wiper, causing premature leakage. We strongly recommend re-chroming or replacing the rod before installing new seals.
Q4: What is the service life of these seals?
A: Under normal operating conditions (clean oil, proper alignment, moderate duty cycles), these seals typically last 4,000–6,000 hours. In extreme conditions (high contamination, high cycle rates), inspect at 1,000-hour intervals and replace as needed.
Q5: Do I need special tools for installation?
A: Basic hand tools are sufficient for most cylinders. However, we recommend using a seal installation cone or tapered sleeve to avoid damaging the lip seals during assembly. Plastic or brass drift tools are also useful for seating O-rings without scratching grooves.
Q6: Are these seals compatible with synthetic hydraulic oils?
A: Yes – the NBR and polyurethane materials are compatible with most synthetic hydrocarbon-based hydraulic fluids (e.g., PAO, diester types). For fully synthetic esters or fire-resistant fluids, please consult COGENG technical support before ordering.
Q7: Is this kit made in the same factory as genuine Komatsu seals?
A: COGENG seals are manufactured in an independent ISO 9001:2015 and IATF 16949 certified facility using materials sourced from leading global compounders. While not sourced from Komatsu's original supplier, our seals are engineered to match or exceed OEM specifications in all critical performance parameters.
Q8: What if the kit arrives with a missing component?
A: Although we perform 100% count verification during packing, in the unlikely event of a shortage, contact COGENG immediately with your order number and photos of the kit contents. We will arrange for the missing parts to be shipped at no extra charge.
For pricing, bulk orders, or technical support, contact your COGENG supplier today.
Please provide your machine model and cylinder serial number for compatibility verification.
Sales Price: Please contact COGENG sales customer service for specific prices.
Shipping method: The specific arrangement will be based on the cargo situation.
Estimated delivery time: It is based on the shipping time of the logistics company, and the arrival time shown shall prevail.
Contact details are at the bottom of this datasheet.
| Feature | Benefit |
|---|---|
| ✅ OEM Replacement | Direct fit for Komatsu 707-52-10700 – no modification or adaption required |
| ✅ Premium Quality | Engineered with advanced polyurethane, NBR, and PTFE materials for leak-proof performance |
| ✅ Leak-Proof Design | Precision-molded lips and exact groove fit eliminate internal bypass and external drips |
| ✅ In Stock — Fast Shipping Worldwide | Available from regional warehouses; express shipping options for urgent repairs |
| ✅ Pre-shipment Verification | Photos and test documentation available – order with complete confidence |
| ✅ Non-returnable but Quality-Backed | Every kit is double-inspected – DOA risk is essentially zero |
| Parameter | Specification |
|---|---|
| Kit Net Weight | Approx. 0.85 kg (depends on cylinder size variant) |
| Rod Seal Type | U-cup with dynamic lip, polyurethane (92 Shore A) |
| Piston Seal Type | Double-acting ring set with PTFE anti-extrusion rings |
| Wiper Seal Type | Single lip, fabric-reinforced NBR (80 Shore A) |
| O-Ring Material | NBR 70 Shore A (standard), HNBR optional for high temp |
| Wear Guide Material | Phenolic resin with woven cotton fabric (low friction) |
| Maximum Operating Pressure | 35 MPa (5,076 psi) continuous; 40 MPa (5,800 psi) peak |
| Maximum Speed | 0.5 m/s for rod seal; 0.3 m/s for piston seal |
| Oil Compatibility | ISO 6743/4 HM, HV, HLP; also biodegradable HEES |
| Hardness Tolerance | ±5 Shore A for all rubber components |
| Shelf Life | 4 years in original unopened packaging |
| Packaging Dimensions | 420 × 320 × 80 mm (carton box) |
| Country of Origin | Manufactured in ISO 9001:2015 / IATF 16949 certified facility |
| Certification | REACH, RoHS, and Conflict Minerals compliant |
This datasheet is for informational purposes only. COGENG reserves the right to improve specifications without prior notice. Always refer to the product label and the installation leaflet included with each seal kit. For cylinders with non-standard dimensions, please contact our technical support team for custom-kit solutions.
*shipping Details Return Sales*
Sales price:
Please contact COGENG sales customer service for specific prices.
Shipping method:
The specific arrangement will be based on the cargo situation.
Estimated delivery time:
It is based on the shipping time of the logistics company, and the arrival time shown shall prevail.
Contact details are at the bottom.
MerchantReturnPolicy:
The products shipped are not returnable or exchangeable.
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