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707-99-66670 Arm Cylinder Seal Kit for Komatsu PC400-7 PC450-7 | Ruijueparts

707-99-66670 Arm Cylinder Seal Kit for Komatsu PC400-7 PC450-7 | Ruijueparts

Regular price $21.99
Regular price Sale price $21.99
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Availability1000 in stock

Volume discounts available · Minimum order quantities apply for bulk pricing

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SKU: 707-99-66670
Vendor: RuiJueParts

Shipping & Returns

Shipping:
- Standard models take 1-3 business days.
- Bulk orders take 3-7 business days.
- For urgent orders, please contact our sales team. [Email: info@ruijueparts.com]

Returns:
We accept returns within 30 days of purchase. Learn more—return policy

Packaging details

PP bag, carton

Place of Origin

China

Payment terms

L/C, T/T, Western Union, MoneyGram

Performance

Oil Sealing

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    Product Description

    Enhance the reliability of your heavy-duty excavator with the 707-99-66670 Arm Cylinder Seal Kit. Specifically engineered for Komatsu PC400-7 and PC450-7 series, this premium aftermarket kit is designed to handle the rigorous demands of high-load excavation. It perfectly fits 185mm bore and 130mm rod cylinders, ensuring a precise seal that prevents "arm drift" and hydraulic fluid leakage. Our kit features high-grade Step Seals and Buffer Seals to maintain consistent hydraulic pressure during intense digging. At Ruijueparts, we provide industrial-strength sealing solutions that match the performance of original parts while offering superior cost-efficiency for your fleet maintenance.

    Item specifics

    Part Number: 707-99-66670
    Fits Models: PC400-7 / PC400LC-7 / PC400-7-M1PC450-7 / PC450LC-7
    Brand: KOMATSU replacement
    Type: Hydraulic Cylinder Repair Kit / Arm Cylinder Seal Kit
    Application:

    A high-performance solution to rebuild and reseal the hydraulic Arm Cylinders on Komatsu PC400-7 and PC450-7 Excavators. This kit is critical for preventing pressure loss, eliminating external leaks, and protecting hydraulic systems from contaminants during large-scale earthmoving, mining, and quarrying operations.

    Size: Standard Size


    FAQ

    • Q1: Does this kit fit the PC400LC-7 and PC450LC-7 long chassis models?
      A: Yes, it is fully compatible with the LC (Long Crawler) versions of the PC400-7 and PC450-7 series using standard arm cylinders.
    • Q2: What components are included in this 707-99-66670 kit?
      A: This is a comprehensive kit including the Step Seal, Buffer Seal, Dust Seal, Piston Seals, Wear Rings, and all necessary O-rings for a complete cylinder rebuild.
    • Q3: Can you help verify if this fits my specific machine serial number?
      A:
      Absolutely. We have a database of over 30,000 part numbers. Simply provide your SN, and our technical team will confirm the compatibility for you.

    Why choose Ruijueparts

    Lower cost — honest trade-off

    Our aftermarket seal kits deliver a practical, cost-effective solution without compromising on real-world performance. We offer a lower upfront cost and reliable sealing for your daily maintenance and repair needs.

    Extensive part number range

    We stock seal kits across CAT, Komatsu, Volvo, JCB, Hitachi, Doosan, John Deere, Kubota, and 10+ other brands—one supplier for your whole fleet.

    Flexible packaging options

    Ship under RuijueParts branding, neutral (unbranded) packaging, or your own private label. Suitable for resellers and distributors.

    Customization Service

    When genuine OEM seals are out of production for your old machinery, we can custom-make oil seals using your dimensions or our engineer-recommended specifications.

    Wholesale & OEM bulk orders

    Ship under RuijueParts branding, neutral (unbranded) packaging, or your own private label. Suitable for resellers and distributors.

    Warranty on request

    Volume pricing for repair shops, dealers, and fleet operators. Get a quote via our website or WhatsApp: +86 13692100161.

    When budget aftermarket makes sense

    OEM seal kits are the right choice when machinery is under active warranty, operating at peak duty cycles, or when failure risk is unacceptably high. Budget aftermarket—like Ruijue Parts—makes sense in these common scenarios:

    Older or end-of-life equipment

    When a machine is aging out of your fleet, OEM parts cost more than the job warrants. A budget kit extends service life without over-investing.

    Secondary or backup machines

    For machines used infrequently or on lower-intensity tasks, premium OEM pricing may not be justified.

    OEM parts unavailable or on long lead time

    When OEM stock is out or delivery takes weeks, an available aftermarket kit gets your machine running now.

    Fleet maintenance on a fixed budget

    Repair shops and fleet managers running high volumes of machines often balance OEM and aftermarket across their portfolio based on criticality.

    Installation guide

    1. Depressurize the hydraulic system

    Fully retract the cylinder and relieve system pressure before disassembly. Never work on a pressurized circuit.

    2. Remove and disassemble the cylinder

    Remove from the machine. Unthread the gland nut and withdraw the piston rod carefully to avoid surface damage.

    3. Clean all components thoroughly

    Clean the bore, rod, and all metal parts with a lint-free cloth. Contamination introduced during reassembly accelerates seal wear—this step is especially important for budget-grade seals.

    4. Inspect the rod and bore

    Check for scoring or pitting. Budget seals are more sensitive to surface imperfections—address rod damage before fitting new seals.

    5. Install the seal kit

    Lightly coat each seal with clean hydraulic fluid before installation. Use proper seal drivers — not screwdrivers or sharp tools — to avoid nicking the sealing lip.

    6. Reassemble and pressure test

    Torque the gland nut to spec and cycle the hydraulic system under no-load conditions. Inspect for leaks before returning the machine to service.

    Maintenance tips

    Inspect every 250–500 hours

    Budget-grade seals may have shorter service intervals than OEM. Inspect rod seals for moisture, oil film, or weeping more frequently and replace proactively.

    Keep hydraulic fluid clean

    Contaminated fluid degrades seals faster — this applies especially to non-OEM materials. Replace fluid and filters on schedule.

    Protect exposed rod surfaces

    When storing equipment with cylinders extended, protect rod surfaces from corrosion and debris to preserve wiper seal life.

    Ensure Proper Installation

    Avoid using sharp tools during assembly to prevent nicks or scores on the seal lips. Pre-lubricating all components with clean hydraulic oil is recommended to ensure a smooth fit into the cylinder grooves.

    Reduce Downtime with Reliable Seals.

    Click "Add to Cart" for immediate dispatch, or contact our team for bulk pricing and wholesale support.

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