Hydraulic systems function by transferring force applied at one end of the system through the compression of an oil-based fluid. The system’s hydraulic pump functions by using the weight of a lager amount of fluid to compress a smaller amount of fluid through a hose to operate pistons that operate an apparatus such as a tractor’s plow or tiller. Over time the bearing and seals in the hydraulic pump will wear out, requiring you to change the tractor’s hydraulic pump.
Lower all hydraulic powered accessories to the ground, using their control levers. Disconnect the tractor’s negative battery cable with a wrench.
Place the drain pan under the hydraulic fluid reservoir and remove the drain plug from the reservoir with a socket wrench. Replace the drain plug after the fluid has drained. Move the drain pan under the hydraulic pump. Open the bleeder valve on the hydraulic pump with a wrench to relieve any pressure in the pump.