Description

Komatsu PC27MR-2, PC30MR-2, PC35MR-2, PC50MR-2 2005 Parts Catalog

If you’re ordering cylinder seals or piston parts for any MR-2 Komatsu, the wrong part number means tearing it apart again. I’ve seen it happen – guy orders a seal kit off some third-party website, gets halfway through the rebuild, and the rod seal is 2mm too thin. That’s billable hours down the drain. This Komatsu PC27MR-2, PC30MR-2, PC35MR-2, PC50MR-2 2005 Parts Catalog is the factory document that lists every internal part for the hydraulic cylinders. Not a reprint. Not a scanned copy from a photocopier. Original OEM pages.

Cylinder Parts Breakdown: What’s Inside

The OCR excerpt from the document starts with a PARTS BREAK DOWN FOR MR-2 CYLINDER. Page 1 shows the registration and purpose: to provide part numbers for hydraulic cylinder internal components. Every cylinder on these machines – boom, boom swing, arm, bucket – gets its own spread. Page 2 shows the boom cylinder with current and updated part numbers side by side. That’s the kind of detail that keeps you from ordering the wrong rod seal or piston ring. The document runs 21 pages, and every one of them is dense with part references.

PC27MR-2 Through PC50MR-2: Which Models Are Covered

This catalog covers four models: PC27MR-2, PC30MR-2, PC35MR-2, and PC50MR-2. If you’ve got a PC40MR-2, that model is not listed here – you’d need the version that includes it (check the Komatsu PC27MR-2 PC30MR-2 PC35MR-2 PC40MR-2 PC50MR-2 Workshop Manual). For the four models covered, the hydraulic cylinders are identical in design across the range? Not exactly. The part numbers differ between the smaller and larger machines. This catalog spells out exactly which part goes where, with current and superseded numbers.

Hydraulic Cylinder Component Numbers: Why OEM Matters

Aftermarket catalogs love to group parts under generic categories like “rod seal kit” without specifying the exact dimensions. Here you get the Komatsu part number, cross-referenced to the cylinder assembly. Need the piston for the arm cylinder on a PC35MR-2? Flip to the arm cylinder page (page 4 of the catalog). The part number is listed with the update history. That’s the difference between a job that stays fixed and one that comes back with a leak. For any rebuild, you also need torque specs – those come from the service manual, not this parts catalog. Pair this with Komatsu PC27MR-2 PC35MR-2 Operators Manual – OEM 261 Pages and Komatsu PC30MR-2 PC35MR-2 Service Manual – 238 Pages OEM Shop Manual for the full package.

21 Pages of Factory Part Numbers

Twenty-one pages sounds thin next to a 500-page service manual, but this is a focused reference. Every page is a single-cylinder breakdown with a table of part numbers, descriptions, and quantities. The boom swing cylinder gets its own spread (page 3), showing current and updated part numbers. That means if a seal was superseded, you see it. You don’t get that from a generic parts lookup site. The document is dated 14/09/2005 and approved by E. Prandini – that’s a Komatsu engineer’s stamp on the data.

Where to Find the Right Seal Kit

Seal kits aren’t listed here as a single part number – you have to look up each o-ring, U-cup, and wiper separately. That’s how Komatsu intended it. If you want a pre-assembled kit, you’ll need to cross-reference the individual numbers. For diesel engine systems that power these machines, see this Wikipedia article on diesel engines for basic theory, but for part numbers stay with OEM documentation. This catalog gives you the exact piece.

Does this catalog include torque specs?

No. This is a parts catalog only. Torque values for cylinder bolts are in the service manual.

How do I identify which cylinder part number I need?

Match your machine model to the correct cylinder – boom, boom swing, arm, or bucket – then note the serial number stamped on the cylinder barrel. The catalog shows current and updated numbers; if you see a superseded number, use the updated one. For example, the boom cylinder on a PC27MR-2 uses part 707-00-XXXXX (refer to page 2 for full list). If the part has been updated, the new number is listed directly below. Always verify by cross-referencing with the hydraulic diagram in the service manual.

Does this catalog cover the PC50MR-2’s boom swing cylinder?

Yes, page 3 covers the boom swing cylinder for PC27MR-2 through PC50MR-2 with current and updated part numbers.

Is this the same as a reprint from a third-party site?

No. This is the original Komatsu Parts & Service News document (registration AR_05_032, 21 pages). Third-party sites often strip out the update history and cross-reference notes. You get the full OEM layout including the template numbers and approvals.

You need the right part number before you order anything. The Komatsu factory manual puts that data in your hands – no guesswork. Access the Factory Manual and keep it on your tablet next to the service manual. One reference for parts, one for procedures. That’s how you finish a job without rework.

Related Manuals:

• Komatsu PC27MR-2 PC30MR-2 PC35MR-2 PC40MR-2 PC50MR-2 Workshop Manual
• Komatsu PC27MR-2 PC35MR-2 Operators Manual – OEM 261 Pages
• Komatsu PC30MR-2 PC35MR-2 Service Manual – 238 Pages OEM Shop Manual