Komatsu Part SEAL 421-20-12740

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Product Overview

The 421-20-12740 SEAL is a genuine Komatsu OEM replacement seal from the 421 prefix series. Seals prevent fluid leakage and contamination ingress at the interfaces between components — keeping your machine's hydraulic oil, engine oil, gear oil, and coolant contained and protected from external contamination.

Part Number: 421-20-12740 Part Name: SEAL Part Type: OEM Komatsu Replacement Seal Availability: In stock — ready to ship

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When to Replace

Replace the 421-20-12740 when fluid is visible at the sealed interface — wetness, staining, or active dripping; when the seal material feels hard, shows cracks, or has taken a compression set; when cuts, nicks, or deformation are visible on the seal lip or face; or whenever the component is disassembled for service.

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Installation

1. Confirm 421-20-12740 in your Komatsu catalog
2. Inspect the sealing surface — grooves or damage will destroy the new seal
3. Clean the seal housing — old seal fragments must be completely removed
4. Lubricate the seal lip with clean system fluid
5. Press to correct depth using the proper seal installation tool
6. Check for leaks after system pressurization

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Request a Quote

Need the Komatsu 421-20-12740 SEAL? Contact us through the form, or by phone, email, or WhatsApp. We respond within one business day.