Kobelco SK135SR Used Excavator Guide & Inspection Tips

The Kobelco SK135SR is designed for buyers who need the working capability of a 13- to 14-ton excavator while keeping rear swing compact. It is especially relevant for road work, utilities, civil engineering, foundations, site preparation and other jobs where a conventional excavator may need too much clearance behind the machine.

For a used buyer, the main task is to identify the exact generation and specification before comparing price. SK135SR-3, SK135SR-5 and SK135SR-7 machines differ in operating weight, engine output, hydraulic equipment and emissions systems. Standard, long-carriage, crane, dozer, telescopic-arm and forestry versions can differ further. This guide explains where the SK135SR fits, what specifications matter, what to inspect, and what to confirm before buying from Japan.

Does the SK135SR Match the Work You Actually Do?

The SK135SR belongs to Kobelco's medium-size rear ultra-short-swing excavator range. Kobelco describes the current SK135SR-7 as a 13-ton-class machine, while the standard Japanese specification lists an operating weight of 14,100 kg.

This class can make sense when a 7- to 8-ton excavator is regularly reaching its practical limits but a conventional 20-ton excavator would be larger than the work requires.

Typical applications can include:

• Road and drainage construction
• Utility trenching
• Urban civil engineering
• Foundation excavation
• Site preparation
• Residential and commercial development
• Loading and general earthmoving
• Slope and embankment work
• Compatible breaker, nibbler and other attachment work

The SK135SR may be unnecessarily large for landscaping and light property work. It may also be too small where high-volume excavation, very deep digging or large truck loading dominates the operation.

Why Short Tail Swing Is the Core Feature

The SK135SR is not simply a smaller version of a conventional excavator. Its defining characteristic is the rear ultra-short-swing layout.

This design reduces the rear clearance required when the upper structure rotates. That can be useful near:

• Traffic lanes
• Buildings
• Retaining walls
• Temporary barriers
• Other machinery
• Restricted site boundaries

Kobelco developed the SK135SR-7 specifically as a 13-ton-class rear ultra-short-swing excavator. The design is therefore most valuable when restricted swing space is a real part of your daily work rather than an occasional issue. :contentReference[oaicite:0]{index=0}

Short tail swing does not mean the entire working envelope stays inside the track width. The boom, arm and bucket still need sufficient clearance, so site layout must be considered as a whole.

SK135SR Generations: The Suffix Changes More Than the Name

Used SK135SR machines from Japan can come from several generations. The differences are large enough to affect parts sourcing, maintenance requirements, fuel and emissions systems, transport weight and purchase value.

Kobelco lists the SK135SR-3 at 13,600 kg with a 0.50 m³ standard bucket. It uses a Mitsubishi D04EG-WDP3TAAC2-5 turbocharged direct-injection diesel engine producing 69.2 kW at 2,000 rpm. :contentReference[oaicite:1]{index=1}

The later SK135SR-5 is listed at 13,900 kg with a 0.50 m³ standard bucket and an Isuzu 4JJ1XDRA diesel producing 73.9 kW at 2,000 rpm. :contentReference[oaicite:2]{index=2}

Kobelco introduced the SK135SR-7 in Japan in May 2021. The standard machine is listed at 14,100 kg with a 0.50 m³ bucket and Isuzu 4JJ1XDRA engine. Its published output is 80.7 kW at 2,200 rpm with the cooling fan under the stated JIS condition, or 86.0 kW without the fan. :contentReference[oaicite:3]{index=3}

Specifications vary by model year, market and configuration. Exact specifications should be confirmed for each individual machine.

Verified Japanese Specification Comparison

These values are useful for comparing generations, but they are not a substitute for checking the exact machine offered for sale.

What the SK135SR-7 Tells Buyers About This Class

Kobelco's current Japanese SK135SR-7 specification gives a useful reference for the machine class. The standard machine has a 0.50 m³ bucket, 14,100 kg operating weight, 500 mm standard shoes and 2,490 mm crawler width. :contentReference[oaicite:4]{index=4}

With the standard 2.38 m arm, Kobelco lists:

• Maximum digging radius: 8,370 mm
• Maximum ground-level digging radius: 8,210 mm
• Maximum digging depth: 5,520 mm
• Maximum digging height: 9,180 mm
• Maximum dump height: 6,750 mm
• Maximum bucket digging force: 105.4 kN
• Maximum arm digging force: 64.0 kN

A 2.84 m long arm is also available. In that configuration, maximum digging depth increases to 5,980 mm and maximum digging radius to 8,810 mm. The standard bucket for that arm is smaller in the published specification. :contentReference[oaicite:5]{index=5}

This is a good example of why buyers should confirm arm length and bucket combination before comparing two apparently similar machines.

The Hydraulic System and Attachment Setup Deserve Close Attention

The SK135SR-7 uses two variable-displacement axial-piston pumps plus one gear pump, with a listed system setting pressure of 34.3 MPa. Kobelco also lists N&B reciprocating attachment piping as standard equipment on the referenced Japanese configuration, while rotating N&B and other piping can be optional. :contentReference[oaicite:6]{index=6}

The manufacturer lists an attachment allowable mass of 1,510 kg with the basic counterweight and 1,680 kg with the additional counterweight under the stated specification. Those figures are not universal attachment limits for every SK135SR generation or operating condition. :contentReference[oaicite:7]{index=7}

If you plan to use a breaker, crusher, grapple or other hydraulic attachment, confirm:

1. The exact hydraulic piping installed.
2. Required hydraulic flow and pressure.
3. Attachment operating direction.
4. Arm specification.
5. Counterweight specification.
6. Permitted attachment mass.
7. What attachment is included with the machine.

An excavator with visible auxiliary pipes should not automatically be assumed compatible with your intended attachment.

Used SK135SR Inspection: Focus on the Expensive Areas First

1. Undercarriage

The undercarriage is one of the first areas to examine because replacement of multiple crawler components can materially change the true purchase cost.

Inspect:

• Track links and shoes
• Sprocket teeth
• Front idlers
• Bottom rollers
• Carrier rollers
• Track tension
• Track frame condition
• Wear differences between left and right sides

Different shoe widths are available for the SK135SR platform. The current SK135SR-7 specification, for example, lists 500, 600 and 700 mm iron shoes. Confirm what is actually fitted rather than assuming standard shoes. :contentReference[oaicite:8]{index=8}

2. Boom, Arm and Structural Areas

Inspect the boom foot, cylinder mounting areas, arm connection and pin bosses for cracks, distortion, reinforcement plates or welding.

A repaired area does not automatically make a used machine unsuitable. However, its location, quality and reason should be understood before purchase, especially if the machine previously operated heavy attachments.

3. Pins and Bushings

Check play at the bucket linkage, arm joint and boom mounting points.

Excessive movement can reduce digging accuracy and indicate upcoming repair costs. Compare wear on both sides of the linkage and look for evidence of irregular lubrication.

4. Hydraulic Cylinders and Hoses

Check cylinder rods for scoring, pitting or corrosion. Look for hydraulic oil around seals, fittings and hoses.

Recently cleaned hydraulic areas deserve the same attention as obviously wet areas because cleaning can temporarily hide a leak.

5. Hydraulic Performance Under Operation

If operational testing is possible, use the boom, arm, bucket, swing and travel functions individually and in combination.

Watch for:

• Jerky movement
• Abnormal pump noise
• Slow operation
• Weak response under load
• Excessive cylinder drift
• Uneven travel performance

For machines with a history of breaker or crusher work, hydraulic condition deserves additional attention.

6. Swing System

The short-tail design means swing operation is central to how the SK135SR is used on restricted sites.

Rotate the upper structure in both directions. Listen for abnormal noise and check for excessive backlash or movement around the swing bearing area.

7. Engine and Emissions Equipment

Where practical, evaluate the engine from a cold start. Check starting behavior, exhaust smoke, idle stability and abnormal mechanical noise.

Also inspect for:

• Engine oil leakage
• Fuel leakage
• Coolant leakage
• Radiator contamination
• Damaged hoses
• Warning indicators

The SK135SR-7 Japanese specification includes a 26 L urea-water tank in addition to its 186 L fuel tank, reflecting the emissions equipment used on this generation. Buyers should consider local access to the correct fluids, diagnostics and maintenance support. :contentReference[oaicite:9]{index=9}

Operating Hours Are Useful Only With Context

A lower-hour SK135SR is not automatically a better machine.

Previous use can make a major difference. A machine used mainly for general excavation may have a different wear pattern from one used in demolition, forestry, recycling or continuous hydraulic attachment work.

Compare operating hours with:

• Undercarriage wear
• Hydraulic performance
• Engine condition
• Pin and bushing play
• Bucket and attachment wear
• Structural repairs
• Cab and control wear
• Previous application
• Maintenance information when available

The relationship between the meter and the physical condition is more useful than the meter value by itself.

Special-Purpose SK135SR Machines Can Be Very Different

This is one of the most important buying points for the SK135SR.

Kobelco has developed the platform for numerous special applications. Official Japanese information lists configurations including high-reach crane, telescopic arm, dozer blade, long reach and forestry machinery. :contentReference[oaicite:10]{index=10}

For example, the SK135SR-7 telescopic-arm version is listed at 15,400 kg and uses a 0.31 m³ bucket, while the standard machine is 14,100 kg with a 0.50 m³ bucket. The telescopic version can reach a maximum digging depth of 7,840 mm when fully extended. :contentReference[oaicite:11]{index=11}

The dozer-blade version is listed at 14,900 kg. Kobelco also publishes forestry SK135SR-7F machines with substantially higher operating weights and additional specialist equipment. :contentReference[oaicite:12]{index=12}

Therefore, do not compare a forestry, crane or telescopic machine directly with a standard bucket excavator only by model name and operating hours.

Lifting Capacity Is Configuration-Specific

Kobelco publishes lifting information for the dedicated high-reach crane specification of the SK135SR-7.

In that approved configuration, Kobelco lists maximum rated lifting of 2.9 tonnes at the stated 2.4 m radius for stationary lifting and 1.4 tonnes for travelling lift under the specified conditions. Capacity reduces as working radius increases. :contentReference[oaicite:13]{index=13}

These values should not be described as the lifting capacity of every SK135SR.

A standard excavator is not automatically equivalent to the manufacturer's crane specification. If lifting will be an important part of your operation, confirm the correct machine configuration, lifting chart, safety equipment and local regulations.

SK75SR or SK135SR: When Is Moving Up Worth It?

The move from the SK75SR class to the SK135SR class is substantial. It should be justified by regular workload rather than occasional need.

The larger SK135SR is useful when the additional capacity is used often enough to justify heavier transport, larger components and higher ownership costs.

SK135SR or a Conventional 20-Ton Excavator?

Some buyers also compare the SK135SR with machines around the 20-ton class.

The SK135SR offers a useful middle position. It provides more capability than compact excavators while remaining significantly lighter than a typical 20-ton machine. Its short-tail design can also be useful where a conventional rear counterweight creates operational restrictions.

Consider staying with the SK135SR class when maneuverability, transport weight and rear clearance matter. Consider moving to a larger class when truck loading, bulk earthmoving and production requirements consistently exceed what a 13- to 14-ton excavator can deliver.

Shipping a Kobelco SK135SR from Japan

An SK135SR requires proper heavy-equipment freight planning. A standard current SK135SR-7 is listed at 14,100 kg and 2,490 mm crawler width in the Japanese specification. Special versions can be substantially heavier. :contentReference[oaicite:14]{index=14}

Before requesting a freight estimate, confirm:

1. Complete model suffix
2. Serial number
3. Standard or special-purpose configuration
4. Actual overall length
5. Actual overall width
6. Actual overall height
7. Transport weight
8. Arm and boom specification
9. Bucket and attachments
10. Counterweight configuration
11. Track width and shoe type
12. Destination port

RORO, flat rack, breakbulk, container or another transport arrangement may be considered depending on the exact machine, dimensions, destination, port, shipping line and current shipping conditions. No single method should be assumed for every SK135SR.

A Buyer Decision Framework for the SK135SR

1. Confirm job fit. Decide whether 13- to 14-ton capability matches the work you perform regularly.
2. Identify the exact generation. Separate SK135SR-3, SK135SR-5, SK135SR-7 and other variants.
3. Identify the configuration. Standard, LC, crane, telescopic, dozer, forestry and long-reach machines can differ significantly.
4. Inspect the expensive wear areas. Give priority to undercarriage, hydraulics and structure.
5. Read hours together with condition. Do not buy on the hour meter alone.
6. Confirm attachment requirements. Check piping, mass limits and counterweight.
7. Verify shipping data. Use actual machine measurements before selecting a transport method.

Buying a Used Kobelco SK135SR from Japan

Japan's used machinery market can include SK135SR machines from different generations and applications. That variety gives buyers more choices, but it also makes model identification and condition assessment essential.

You can check current Japanese used machinery available at EVERYCAR.jp. Stock changes regularly, so availability of a specific SK135SR generation or configuration should be confirmed from the current inventory.

For more information about excavator sizes, Japanese manufacturers and used machinery purchasing, see the Japanese Used Machinery & Heavy Equipment Guide | 100 Articles.

Should You Buy a Used Kobelco SK135SR?

The SK135SR is a strong candidate for buyers who need a meaningful step up from compact excavators while still placing high value on reduced rear swing. It suits construction, utility, civil engineering and site-development work where both productivity and maneuverability are important.

Do not choose a machine from the SK135SR badge alone. Confirm the generation and configuration, then evaluate its undercarriage, hydraulics, engine, structural condition, pins and previous attachment use. Finally, compare its working range, transport requirements and maintenance needs with your actual operating environment.

If you are looking for a Kobelco excavator or other used machinery from Japan, you can contact EVERY with your preferred manufacturer, model, size, budget, intended application and destination. Those details provide a practical basis for comparing available machinery with your work requirements.