Abstract Water hydraulics captured the imagination of engineers some 2500 years ago and recently it has revived to become a powerful alternative in areas where the environment and health are of great concern. Previously, this field of knowledge suffered some setbacks as technology was still at its developing stage, but with better tolerances and the availability of better materials, this technology is now a reality. This paper focuses on the fault diagnosis of the condition of hydraulic actuators working on the principle of tap water hydraulic power systems. Two common actuators were explored, namely a water hydraulic cylinder and a water hydraulic axial piston motor. Possible real-life faults were simulated on the actuator’s internal component. The cylinder was operated with worn piston or rod seals whereas the motor has worn capstan and piston shoes in place. These actuators were operated to capture their unique vibration signals in their faulty states to be compared with their ‘healthy’ condition state. Both actuators were loaded in steps for trend observation in the vibration signatures. Results show that, in general, there is a change in vibration signals, flow rate and average operation duration when more load is added to the actuators. If a fault has occurred internally, it will also correspond to another change in the above parameters in the spectra plotted. With this knowledge, LabVIEW software can be written to set warning levels that will trigger an alarm when a fault is impending.