RK25 Tractor Problems : 6 Common Issues And Solutions

RK tractors are known for being top of the line. They deliver unparalleled performance thanks to the powerful Yanmar diesel engines such as the one used in the RK25H. The tractors are very robust and can be fitted with several different attachments to suit the needs of the farmer. Despite however the remarkable performance of the RK25 tractor it is not perfect and can develop problems if not properly maintained.

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What Is The RK25 Tractor?

The RK25 tractor is a remarkable subcompact tractor by the manufacturer TYM. The tractor uses a powerful 3-cylinder Yanmar diesel engine that is liquid cooled and produces 24HP. The tractor also uses a 2-range hydrostatic transmission and auto-throttle. It can haul greater amounts of loads thanks to the 4WD drive system with a differential lock.

RK25 Tractor Problems

NB: The RK25 tractor is usually sold without any defects and any problems that may arise, including those highlighted below in this article are usually caused by wear and tear arising on the tractor while it is being used.

1. Engine Does Not Start

The engine is used in the RK25 tractor to propel the tractor forward and run all the other equipment in the tractor, hence the engine failing to start is a serious problem. One may find that the start motor is running but the engine can’t be started. This problem may be caused by;

  • Air in the fuel system or a clogged fuel filter.
  • No fuel supply or defective engine.
  • A defective key stop unit.

Troubleshooting Engine Problems

In order to eliminate faults developing with the engine, one can try to solve the problem by using the following procedures;

  • Bleeding the fuel system to remove air and cleaning or replacing the clogged fuel filter.
  • Opening the cock and adding fuel, and also having a thorough inspection on the engine in-order to identify and replace worn out parts.
  • Having the key stop unit repaired or replaced by trained professionals.

2. Engine Overheating

Engine overheating is a serious problem since it can lead to the permanent damage of the engine components such as the piston and piston rings. Engine overheating can be caused by the following problems

  • Insufficient coolant amount circulating around the engine.
  • Loose or damaged fan belt or a clogged radiator.
  • Insufficient engine oil circulating around the engine.

Troubleshooting Engine Overheating

In order to ensure that the engine stops overheating, the following can be done to try and address the issue;

  • Adding more coolant to the required level.
  • Adjusting the fan belt tension to allow for proper power transfer and cleaning the radiator to allow for proper heat dissipation.
  • Regularly inspecting and replenishing the engine oil in order to ensure it is at the appropriate level.

3. Brake Malfunction

Without the brakes the RK25 tractor can’t be brought to a proper stand still in sufficient time. The brakes are therefore very important and allow one to easily control the maneuvering of the tractor. Problems with the RK25 tractor brakes can be caused by;

  • Excessive brake pedal free-play due to loosened components in the system.
  • Worn out brake liner hence the brakes don’t sufficiently hold.
  • Different play of the left and right pedals, or pedals failing to return to the original position due to a damaged brake spring or lack of greasing on sliding parts.

Troubleshooting Brakes Malfunction

In order to solve any problems relating to the brakes and restore proper function, the following can be done;

  • Adjusting the free play of the brake pedal and tightening any loose components.
  • Repairing or replacing the worn brake liner so as to ensure the brakes can hold.
  • Setting the left and right foot pedal to the same, appropriate free play, and replacing the damaged brake spring. One should also remove any rust and apply grease to sliding parts.

4. Faulty Steering Wheel Mechanism

The steering wheel mechanism is used in the RK25 tractor to steer and maneuver the direction of the tractor. The steering wheel mechanism is therefore a crucial component of the tractor and without it one cannot properly control the tractor. Problems with the steering mechanism can include;

  • Steering wheel feeling heavy due to Improper toe-in and incorrect tire inflation pressure.
  • Steering wheel vibrating due to loosened connections.
  • Excessive free movement of the steering wheel due to a worn steering shaft and other metal components.

Troubleshooting Faulty Steering Mechanism

In order to solve problems with the steering wheel mechanisms one can try do the following procedures;

  • Properly adjusting the toe-in and setting the correct specified tire pressure to the left and right tires.
  • Tightening or replacing any loose connections in the steering mechanism.
  • Replacing the worn steering shaft and any other worn metal parts.

5. Problematic Hydraulic System

The hydraulic system is a crucial component of the RK25 tractor since it is used to actuate the power systems of the tractor. Problems with the hydraulic system can be caused by;

  • Oil leaks due to loosened clamps and cracked pipes.
  • Hydraulic pressure failing to be reduced due to a damaged cylinder or a fixed lowering speed control lever.
  • Hydraulic pressure failing to be increased due to insufficient engine Rpm or insufficient transmission fluid.

Troubleshooting Problematic Hydraulic System

In order to solve problems with the hydraulic system one can try the following;

  • Tightening clamps and replacing cracked pipes.
  • Replacing the damaged cylinder and lowering the speed control lever to the appropriate lowered position.
  • Setting engine speed between 1,000 to 1,500 RPM and adding transmission fluid to the correct level.

6. Battery Failing To Charge

The battery is a very crucial component as it provides power to start the engine and also powers other components of the RK25 tractor. Reasons for the battery failing to charge can include;

  • Defective wiring or defective alternator.
  • Loose or damaged fan belt.
  • Defective battery or blown fusible link.

Troubleshooting Battery Inability To Charge

When the battery develops problems, the following can be done to address the problems;

  • Inspecting all the wiring for loose or missing terminals, short circuit and poor grounding. If the wiring is faulty, it may need repairing or replacing, along with a defective alternator.
  • Adjusting the tension of the fan belt or replacing the belt when it becomes defective.
  • Checking looseness or corrosion on terminals and insufficient electrolyte. Refill the electrolyte or totally replace the battery when it becomes defective. One should also check and replace the fusible link when it becomes blown on the RK25

How To Avoid RK25 Tractor Problems?

The best way to avoid any problems developing with the RK25 tractor is to utilize the tractor’s operator manual and only using the tractor as stated in the manual. Following the stipulated maintenance schedule of the tractor is highly recommended. Also avoid using the RK25 tractor in environments where it may be prone to fail so as to prolong the life of the tractor.

How Much Can An RK25 Tractor Lift?

The RK2t tractor can lift loads up to 1,380 Ibs at a height of 87 inches and the breakout force is 2,059 Ibs.

Who Makes Rk Tractors?

RK tractors are made in South Korea by TYM. The company manufactures compact tractors for leading U.S tractor brands. The tractors feature the Yanmar (19-55HP) and Deutz (74HP) diesel engines.


In conclusion RK 25 tractors are very powerful and feature powerful engines such as the 3-cylinder Yanmar diesel engine in the RK 25H. Maintenance and regular service however, should be a must in order to ensure the tractor functions as intended and lasts a long period of time.