A hydraulic filter cart is a portable filtration unit designed to remove contaminants from hydraulic fluids. It consists of a pump, filters, hoses, and a reservoir. To use a hydraulic filter cart, connect it to the hydraulic system, activate the pump, and monitor the filtration process. It helps maintain fluid cleanliness, extends component life, and ensures optimal hydraulic system performance. Regularly changing and disposing of used filters is crucial for effective filtration.