Kubota KX040-4 Excavator: Problems, Durability, and Specs

Modern excavators come in different shapes, sizes, and abilities. Most come equipped with various attachments, powerful hydraulic pumps, priority, and specialized controls, and a plethora of intricate functions that make them stand out from the rest.

The Kubota KX040-4 series is a versatile mini-excavator that incorporates industrial best-practice technology to deliver a balanced superior performance over its peers. With its state-of-the-art production technology, the Kubota KX040-4 is fuel efficient, comes with reduced emissions, and produces far less noise than other mini-excavators in the market.

In today's article, we shall explore the Kubota KX040-4 specs, its durability, and problems you are likely to encounter when using the excavator.

Specs

The Kubota KX040-4 is a stable, powerful, and versatile excavator designed for efficiency and stability in operations. Its versatility suits it for the toughest of conditions and comes with a combination of improved digging capability, smooth traveling performance, and unbelievable lifting power. It comes with several other different attachments that can be fixed to the excavator to perform different tasks.

The KX040-4 has one of the best mini excavators' cab designs that provide excellent vision, a perfectly positioned monitor that minimize reflective glares to the operator, heavy-duty floor mats, and an adjustable all-weather seat.

The control consoles are well placed for the convenience of the operator while the blade is placed to the right of the dashboard console which enables the operator to have a clear vision regardless of his position.

Weighing 4.2 tonnes, the KX040-4 is powered by a D1803-CR Tier IV3 cylinder engine running on diesel. The 1862cc engine produces 29Kw of power (42.4 Horsepower) and can reach a top speed of 5KM/hour. Its bucket can hold up to 4 cubic yards of material. The table below provides a summary of the impressive Kubota KX040-4 specs:

Other specs

• The Kubota KX040-4 engine has an electronically controlled fuel injection that uses the common rail system. The timing and the amount of fuel injection are done in stages to optimize combustion. This method increases fuel economy, efficiency, and engine noise reduction. This process is applied alongside the modern DPF and Exhaust Gas Recirculation to minimize harmful emissions and be compliant with the latest emission levels requirement.
• The Kubota engine comes with an automatic DPF regeneration system that can be turned off whenever required.
• It has a standard thumb-operated auxiliary circuit switch for easy control of all attachments. This control enables easy adjustment of oil flow required for different operations.
• It comes with an optional hydraulic angle blade that can be angled to the left or right as the machine moves forward. This avoids repetitive maneuvers for repositioning when carrying out backfilling.
• The excavator has a two-speed auto-shift system that switches from low to high and vice versa depending on terrain or traction. These specs provide efficiency, maneuverability, and seamless backfill operations.
• It has a 2-pattern selection system located under the seat that allows convenient shifting and control of the modes required.

Problems

1) Fuel Delivery Problems

The Kubota KX040-4 experiences fuel delivery problems especially when it begins to age. The fuel delivery to the engine is hampered by the injectors which become worn out or blocked. The problem manifests itself through low engine power and black smoke. The solution is to replace the injector pump.

2) Other Fuel Issues

At times, the Kubota KX040-4 fails to run at full power, sometimes tumbling along or dying off periodically. This stumble happens at about 35% throttle, and whenever the accelerator is depressed further, the engine dies off. The problem is usually caused by a loose nipple in the water separator outlet. The loose nipple allows extra air to inject into the diesel fuels system leading to an interruption in the combustion process. The interruption cause the engine to start tumbling and it loses power to perform.

3) Failure to start/Hard Start

One of the biggest problems affecting the Kubota KX 040-4 excavator is a constant failure to start, or having a hard start. Usually, usually, when you press the start button, the excavator only gives a clicking sound as lights flash but it does not start. Failure to start can be a result of corroded/worn-out electrical connections, a malfunctioning starter motor, a dead battery, overheating, clogged filters, or broken relays/solenoids. These components tend to become faulty over time, leading to this problem starting.

Proper maintenance and regular checks on batteries, solenoids, relays, switches, and filters need to avoid having the problem.

4) Oil Leakages

Like most other heavy construction machinery, the Kubota KX040-4 excavator suffers from frequent oil leaks. Such leaks lead to unnoticeable low levels of oil in the engine and other areas that rely on oil to operate. The low oil level may cause the excavator to have operational issues and may even stall completely. Oil leakages from the hydraulic pump may also cause the Hydraulic pump to fail. Apart from stalling the excavator, such a failure may lead to expensive damage to the engine.

It is important to keep a close check on the oil levels in the Kubota KX040-4 and if noticed, the source of the leakage should be identified and rectified.

5) Overheating Engine

The Kubota KX040-4 is prone to engine overheating as a result of a faulty cooling system. When engine temperature rises beyond the recommended high, it stops working correctly and may even seize or destroy other vital components

Overheating can result from leaking of coolant, blocked cooling, or broken water/coolant seals. The hydraulic fluid in the hydraulic pumps may also become contaminated with moisture, dust, dirt, and other debris as a result of improper sealing. When these faults occur, the engine cooling system is unable to carry off the excess heat from the engine. Considering the heavy work of the Kubota KX040-4 excavator, the working temperatures of the engine may rise beyond the limits, reducing the performance of the engine.

Any engine overheating must be dealt with to avoid total collapse.

6) Stalls

The Kubota excavator is prone to bog downs and stalls. When it remains idle for a few days, it fails to kick into life smoothly when it is started. The engine starts perfectly and runs for a few minutes before it the engine begins to sputter, jerk, and shake while releasing whitish-black smoke from the exhaust. Eventually, the engine stalls. The stall or bogging occurs whether the engine is left to run on idling, or the accelerator is at 35% of its normal capacity. The problem may result from insufficient fuel, stale fuel, or excess engine oil.

7) Hydraulic Thumb Problems

The hydraulic thumb operations in the Kubota excavator are another common problem. The hydraulic thumb is a versatile application that provides flexibility in the excavation and lifting of bulky loads and debris with precision. The hydraulic thumb is made to provide a wide range of motion, easy control, speed, and accuracy with bulky loads.

When you turn on your hydraulic thumb check valve, it usually pulls away from the hydraulic pump. This process wears away the hydraulic cylinders, eventually preventing them from operating normally. Since the Hydraulic thumb control valve has to be always turned on to be ready for use, it quickly wears down and begins to bring issues for the Kubota KX040-4. 

It is critical to always ensure the hydraulic thumb valves are stuck and bound and also make sure the pressure release valves are present before beginning operations. To maintain the hydraulic thumb, ensure there are no oil and gas leakages or corrosion.

8) Stability

One of the major problems of the KX040-4 is its poor stability. The excavator is very unstable when especially when lifting heavy loads, or when it is operating on uneven ground. The instability of the excavator also makes it hard to control when in use. Thus, it becomes extremely unreliable when carrying out delicate tasks. This makes it a risky excavator that can easily cause accidents if not handled with care.

Durability

An excavator is expensive machinery and its durability is a major consideration when buying. Though the lifetime of the excavator is mainly reliant on level of maintenance, a quality excavator should give a minimum of 9000 hours. On average, the KX040-4 should run for between 9,500 to 10,000 hours of quality service.

However, by the time the KX040-4 reaches this milestone, most of the parts will have undergone some major repairs or replacements to keep them operational. The most vulnerable parts of the excavator are the undercarriage and the tracks. These sections tend to suffer from wear and exhibit various mechanical issues that require attention from time to time. The lifespan of the Kubota KX040-4, like any other machinery can fluctuate depending on the quality of maintenance routine and the operational habits.