Hydraulic breaker for Kubota mini excavators: which Promove model fits?

Many owners of Kubota mini and midi excavators add a hydraulic breaker for demolition, trenching or road construction work. Four Promove breakers cover the Kubota models in this guide, from the KX027-4 to the KX080-4: the XP151, XP200, XP300 and XP400. Together their carrier classes span 1.8–10 t. Which one fits depends on the operating weight of your Kubota and on what its auxiliary circuit delivers.

This guide gives a fit table by Kubota model, the datasheet values of the four breakers side by side, and the checks we run before we confirm fit in a written quote. The table is a starting point, not a final answer: the data plate of your machine and its hammer circuit decide.

Kubota models and the Promove breaker to check first

The operating weights below come from Kubota specification sheets and brochures. Cab and canopy versions differ, and so do machines with another counterweight, track type or quick coupler, so always compare them with the data plate of your own machine.

Kubota model	Operating weight	Promove model to check first
Kubota KX027-4	2.6–2.7 t	Promove XP151 / Promove XP200
Kubota U27-4	2.57–2.67 t	Promove XP151 / Promove XP200
Kubota KX030-4	2.80–2.87 t	Promove XP151 / Promove XP200
Kubota U36-4	3.6–3.9 t	Promove XP200
Kubota U48-4	4.8–4.9 t	Promove XP300
Kubota U50-5	4.9–5.0 t	Promove XP300
Kubota KX057-6	5.5–5.6 t	Promove XP300
Kubota KX060-5	5.6–5.7 t	Promove XP300
Kubota KX080-4	8.2–8.7 t	Promove XP400

Where two models are listed, the machine sits in a zone where both breakers are in class, and the auxiliary circuit decides. Kubota models that are not in this table can be checked the same way: find the operating weight, then compare it with the carrier classes below.

XP151, XP200, XP300 and XP400 side by side

All values below come from the Promove datasheets shown on our product pages.

The XP200 and the XP300 share the same 330 × 330 mm cover plate, and the XP300 and the XP400 use the same 80 mm tool diameter. The XP151 is the lightest of the four and has its own 275 × 275 mm plate, while the XP400 is the heaviest and comes with a 395 × 440 mm plate.

First check: the operating weight of your excavator

Kubota names its machines by size, but the model name is not the operating weight. A U27-4 with a canopy is lighter than the same machine with a cab, and an extra counterweight or a heavier bucket changes the value again. Take the operating weight from the data plate or the manual and check it against the carrier class and the optimal range of each breaker in the tables above. If your machine is close to the edge of a carrier class, tell us, and we check stability and reach with you before we confirm fit.

Second check: auxiliary oil flow and pressure

A breaker only works as intended if the auxiliary circuit delivers the flow and pressure it was designed for. The XP151 needs 25–35 l/min at 110–130 bar, the XP200 needs 40–60 l/min at 100–110 bar, the XP300 needs 50–60 l/min at 110–130 bar and the XP400 needs 70–80 l/min at 120–140 bar. On Kubota machines where the auxiliary flow can be adjusted, the setting for the hammer circuit has to match the breaker, not the maximum the machine can deliver.

You find the auxiliary circuit data in the excavator manual, or your machine dealer can tell you. If the manual lists several modes, use the values for the hammer circuit. Too little flow makes the breaker slow, while too much flow or pressure overloads it and shortens its service life.

Third check: relief valve and return line

The relief valve of the breaker circuit on the excavator is set to 180 bar for the XP151, 160 bar for the XP200, 180 bar for the XP300 and 190 bar for the XP400. All four breakers allow a maximum back pressure of 25 bar in the return line. If your Kubota has no direct return line to the tank, the back pressure can be too high; we check this with you before we confirm fit.

Mounting: cover plate, coupler and adapter plate

Each breaker comes with a bolt-on cover plate: 275 × 275 mm, 15 mm thick on the XP151; 330 × 330 mm, 15 mm thick on the XP200 and the XP300; and 395 × 440 mm, 20 mm thick on the XP400. All four are supplied with hydraulic hoses and a moil (conical) point.

Kubota mini excavators run either a quick coupler or a pin-on mount. The breaker then needs a top bracket or adapter plate that matches your coupler type or your pin dimensions. This part is not included as standard; whether and how it is supplied is confirmed in the written quote.

Where two Promove models overlap

The KX027-4 (2.6–2.7 t), the U27-4 (2.57–2.67 t) and the KX030-4 (2.80–2.87 t) all sit inside the XP151 optimal range of 2.2–3.6 t and at the lower end of the XP200 carrier class of 2.5–5.2 t. Here the hammer circuit decides: if it delivers 25–35 l/min, the XP151 is the match; if it delivers 40–60 l/min, look at the XP200. The U36-4 (3.6–3.9 t) is inside the XP200 optimal range of 3–4.5 t.

The U48-4, U50-5, KX057-6 and KX060-5 are inside the XP300 optimal range of 4.5–8 t. The KX057-6 and the KX060-5 are also at the lower end of the XP400 carrier class (5.5–10 t), below its optimal range, so for most work the XP300 is the closer match. The KX080-4 (8.2–8.7 t) is inside the XP400 optimal range of 6.5–9 t and above the XP300 optimal range, which makes the XP400 the model to check first.

What to send us for a fit check

Send these details with your enquiry, and we check them against the datasheet:

• excavator make, model and operating weight,
• quick coupler type or pin dimensions,
• flow and pressure of the auxiliary hydraulic circuit,
• relief valve setting, and whether the return line goes directly to the tank,
• your company name and VAT number.

Running a Kubota model that is not listed here, or a machine from another brand? Send us the model and the operating weight, and we check it against the same datasheets.

How ordering works (B2B only)

Thunderline is an Authorised Promove dealer. We sell to business customers with a valid VAT number issued in the country of delivery, verified in VIES. You receive a written quote for the breaker and any bracket or adapter plate, with the freight to your site shown as a separate line. Payment is only due after we have checked your VAT number, confirmed fit and you have accepted the quote.

Warranty: 12-month warranty from the date of delivery, claims handled through Thunderline.

Ready to choose? See the Promove XP151, the Promove XP200, the Promove XP300 or the Promove XP400, or request a written quote with your Kubota model and machine details. Quote within 2 hours.

CE marked – manufacturer's Certificate of Conformity (CoC) supplied with the machine on delivery.

Kubota and the Kubota model names are trademarks of their owner. They are used here only to describe the machines we check against the Promove datasheets.