Bobcat 331 Problems (Solutions Included)

Bobcat 331 is a 40hp diesel engine powered compact excavator. It comes in different models equipped with rubber tracks. The Bobcat 331 mini excavator has the ability to be coupled with multiple attachments making it more versatile as compared to skid steer. The soft-touch controls of the excavator enables you to have full control of the machine. Despite its versatility and power abilities, the excavator is susceptible to problems just like any other excavator in industry. Problems range from electrical, mechanical and hydraulic problems.

Table of Contents

Mechanical Problems

These problems with Bobcat 331 excavator arises from failure of mechanical components. Usually failure comes from wear and tear of parts during use. Mechanical components experiences stress and fatigue due to working environment and forces they have to withstand and with time they fail causing problems.


This occurs when excavator tracks move out of position and therefore the excavator won’t be able to properly move from point A to point B. Bobcat 331 excavator experiences de-tracking problem due to number of factors including excessive track tension, worn out track guides and rollers and loose track bolts. The most notable cause of these failures is movement of excavator on rough terrain and poor maintenance practices. Periodic inspections are required for efficient and reliability of the excavator. It is advisable to follow supplier recommendations strictly to avoid these problems in Bobcat 331 excavator. All worn out components should be replaced and loose bolts tightened always. To prolong the lifespan of the tracks, avoid sharp turns and long distance movement on rough terrain. Instead use low bed trucks for transportation of your excavator.

Boom Failure

The boom is also another part that fails on Bobcat 331 excavator. The boom links are secured using high strength pins. These pins keeps the boom in place during the movement of boom and excavation process. Without proper lubrication the pins sometimes get stuck and fail to rotate. They start rubbing against the boom joint and wear out. This results in the boom not being flexible in its movement either in extension or retraction even with good condition cylinders. To troubleshoot pins problem, inspect all the joints for proper lubrication, traces of grease should be visible to show that greasing nipples are not blocked. Always ensure all boom joints and links are adequately lubricated using correct grease type as prescribed by supplier. Excessively worn out pins should be replaced.

The other component to check if boom is not working are the hydraulic cylinders. Bobcat 331 excavator cylinders experiences failures due to wear and tear, seals failure and piston damage resulting in boom malfunction. When hydraulic cylinders are faulty, the boom will not be able to retract or extend to execute its excavation operation. Firstly, check all the cylinder for signs of hydraulic fluid leakages and piston damages. Any seals broken should be replaced and loose pipe fittings tightened to avoid these leakages.

If no leakages and damages are visually noticeable, check the hydraulic pump functionality by removing outlet pipe and switching the engine on momentarily. Hydraulic fluid should be forced out to confirm pump functionality. Take precaution against pressurized fluid to avoid skin irritation and burns. If not sure contact competent person to solve the problem. Faulty hydraulic pumps should be repaired where possible otherwise replacement is the best option.

Boom failure problem in Bobcat 331 can also be as a result of failure of fluid control valves. These units fail due to contamination and natural wear and should be replaced.

Engine Problems

The engine problems include engine overheating and piston failure. Engine failure is mostly driven by natural wear, poor lubrication and cooling system efficiencies. Engine overheating should be avoided as it also results in damage to various engine parts particularly seals and gaskets due to high temperatures. To keep check against engine overheating, periodic checks are required for engine coolant level, coolant temperature sensor and radiator functionality. All these elements if not properly maintained may affect the engine cooling system resulting in excessive engine temperatures. Faulty components of the engine, coolant and filters requires periodic cleaning and replacement to keep engine performance optimum. Coolant should not be allowed to drop below minimum recommended levels and always use correct coolant to top up the engine. Using wrong coolant may also present challenges to your engine. Water pump and fan belts also should be always checked. Like any other mechanical components they wear with time and affect the performance of Bobcat 331 excavator engine resulting in overheating problem. Another big cause for engine overheating is coolant leakages which should be solved by replacing all broken seals.

Transmission Failure

Transmission plays an important role in excavator operation and as such requires maintenance as recommended by supplier to keep it at optimum. Transmission problems in Bobcat 331 excavator may be caused by excessive and sudden loss of hydraulic oil. Transmission fluid is very important in lubricating and cooling the gears within the transmission system. If gears are not lubricated and cooled efficiently, they wear out and results in improper gear operation and ultimately the transmission fails. Transmission noises are also caused by lack of gear lubrication. To solve this problem in Bobcat 331 excavator, always ensure that the transmission fluid levels are within the recommended levels. Avoid use of wrong type and contaminated transmission fluid. Sometimes transmission fluid filters gets clogged and restricts the flow of the fluid. It is therefore recommended to periodically clean the filters and replace them as per supplier recommendation.

Hydraulic System Failure

Hydraulic system plays a pivotal role in all hydraulic systems operation. Care and maintenance of hydraulic systems should done religiously to avoid failures of basic components of the system including the hydraulic pump, control valves, hydraulic cylinders and pipes which causes failure of the whole system

Hydraulic Pump Failure

One good way of determining pump functionality is by removing the pump outlet pipe and switching on the engine, hydraulic oil should be ejected from the pipe outlet otherwise the pump is not working. Exercise caution in doing the above test to avoid skin burns and irritation from high temperature fluid. Bobcat 331 excavator hydraulic problems associated with the pump requires technical person to deal with them. It is not recommended to carry out pump repairs without technical knowledge as this may cause serious damage to other engine components. In worst cases faulty pumps requires replacement with good working unit of same capacity.

Hydraulic fluid leakages

Leakages present a problem to all excavators including Bobcat 331. Leakages are notable due to their contamination of areas where they occur making them easy to identify. Leakages result from wear and tear of seals, gaskets, fittings, pipes and broken fluid reservoirs. All these items require periodic service as recommended by supplier to keep them in good working order. All worn out components should be replaced with good working units. Loose connections and fittings should be tightened as recommended by supplier.