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436-8721 Lift Cylinder Seal Kit For Caterpillar | Ruijueparts

436-8721 Lift Cylinder Seal Kit For Caterpillar | Ruijueparts

Regular price $14.18
Regular price Sale price $14.18
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Volume discounts available · Minimum order quantities apply for bulk pricing

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SKU: 436-8721
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

The 436-8721 Lift Cylinder Seal Kit is an aftermarket reseal kit for the front-loader lift or boom cylinder on selected Caterpillar backhoe loaders. Available application catalogs associate it with 434, 434F, 434F2, 444, 444F, and 444F2 configurations. Fitment must be confirmed by machine serial number and cylinder group before ordering. Depressurize, remove, clean, inspect, reseal, assemble, and test the matched cylinder. Ruijueparts offers 100,000+ part-number searches, custom support for older equipment, and neutral or requested packaging.


Item specifics

Part Number: 436-8721 
Fits Models: 434, 444, 434F, 434F2, 444F, 444F2
Brand: CATERPILLAR replacement
Type: Lift Cylinder Seal Kit / Aftermarket Replacement Parts
Application:
  • Equipment: Selected Caterpillar 434 and 444 Series backhoe loaders
  • Cylinder Function: Front-loader lift cylinder, also described as the loader boom cylinder

  • Direct Industry Catalog Reference: 434, 444
  • Additional Cross-Reference Listings: 434F, 434F2, 444F, 444F2
Size: Standard Size


FAQ

  • Q1: What cylinder does the 436-8721 seal kit repair?
    A: Available application catalogs identify it for the front-loader lift cylinder on selected 434 and 444 Series backhoe loaders. This cylinder may also be described as the loader boom or loader-arm lift cylinder.
  • Q2: Does 436-8721 fit the 434F2 and 444F2?
    A: Some aftermarket cross-reference listings include the 434F2 and 444F2, but public application data is limited. Confirm the complete machine serial number and installed cylinder group before treating these models as verified fitments.
  • Q3: What seals are included in the 436-8721 kit?
    A:
    Reliable public sources do not provide an individual component list. Request the supplier’s packing list or a kit photograph and compare the rod seal, wiper, piston seal, wear rings, backup rings, and O-rings with the removed components.

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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