Intro

The RD809-72090 arm cylinder seal kit is the factory-referenced repair set for the arm cylinder of Kubota KX080-3 and KX080-4 compact excavators. This is the genuine Kubota part number RD809-72090 “KIT SEAL, ARM”, and our aftermarket kit is built to the same application — 100 mm bore × 60 mm rod — so the arm cylinder can be rebuilt instead of replaced when it starts to drift or leak.

For compact excavators working in tight sites, the arm cylinder cycles constantly. A complete seal kit rebuild keeps the cylinder pulling cleanly, prevents rod-side weep, and stops dirt being dragged past a tired wiper into the hydraulic system.

Verified Application

Verified against the official Kubota parts store, Messicks (Kubota dealer) and independent seal-kit specialists:

• Kubota KX080-3 compact excavator — arm cylinder
• Kubota KX080-4 compact excavator — arm cylinder

Page-level claims for KX080-3T, KX080-4S and KX080-4S2 variants are not confirmed by independent sources — if your machine is a letter-suffix variant, confirm the cylinder casting number with us before ordering.

Replacement Scope

• Position: arm cylinder (rebuilds Kubota cylinder RD809-67600 per Hydraulic Cylinders Inc; one source also cites RD809-67603 — check your casting).
• Dimensions: 100 mm bore × 60 mm rod (verified).
• Kit type: complete arm seal kit for a full cylinder overhaul.

Fitment Verification

Verify before ordering: (1) the casting number on your arm cylinder (RD809-67600 or RD809-67603 both appear in the market for this kit); (2) the machine model plate (KX080-3 / KX080-4); (3) bore and rod measurements of 100 mm and 60 mm. If the measurements match but the casting is different, send us a photo — we will confirm whether this kit applies before dispatch.

Factory Inspection & Packing

Each RD809-72090 kit is assembled to the verified 100 mm × 60 mm application, checked piece-by-piece against the picking list, and dimensionally spot-checked before sealing. Kits ship in sealed packaging inside reinforced export cartons, with neutral or DJF-branded labels available for the wholesale trade.

Wholesale Ordering

Factory-direct supply for parts dealers, repair workshops and rental fleets. Bulk and mixed-lot quotations are available, and we can hold scheduled quantities for regular buyers. Email [email protected] or contact Phone / WeChat / WhatsApp: +86 15302478615.

MOQ

MOQ: 5 kits. Mixed-lot wholesale orders are welcome — combine this kit with boom, bucket or other cylinder kits on one quotation; request the MOQ and tier pricing in your enquiry.

FAQ

Q: Is RD809-72090 a genuine Kubota part number?

A: Yes. The official Kubota parts store and Kubota dealer catalogs list RD809-72090 as “KIT SEAL, ARM”. This product is an aftermarket replacement built to that application.

Q: Which excavators does this kit fit?

A: Independent sources confirm the Kubota KX080-3 and KX080-4 compact excavators, arm cylinder. Letter-suffix variants are not independently confirmed — check the cylinder casting before ordering.

Q: What are the cylinder dimensions for this kit?

A: 100 mm bore × 60 mm rod, as documented by Hydraulic Cylinders Inc for this part number.

Q: Can you combine this kit with other Kubota seal kits in one order?

A: Yes — mixed-lot wholesale orders are standard for us; combine RD809-72090 with boom, bucket or other cylinder kits on a single quotation.