A hydraulic fluid reservoir and hydraulic pump combination has at least one hydraulic fluid port and includes a container with a hollow body having a top and a conduit having a bottom within the container and a top above the bottom. The conduit has an opening adjacent to the bottom of the conduit. The opening is spaced apart below the top of the container. A closure member is releasably, sealingly connected to the top of the conduit. Hydraulic fluid can be added to the container via the conduit up to the level of the opening of the conduit. Addition of further hydraulic fluid fills the conduit to the top thereof and the conduit overflows if additional hydraulic fluid is added after the top of the conduit is reached by the fluid. Preferably the container has a main interior chamber and a smaller chamber which is adjacent to one of the side walls of the container. The smaller chamber is has a bottom opening near the bottom of the smaller chamber which communicates with the main interior chamber. Hydraulic fluid enters the smaller chamber through the opening and reaches the level of hydraulic fluid in the main interior chamber. Bubbles in the hydraulic fluid within the main interior chamber are isolated from the smaller chamber and accordingly do not impair the reading of the hydraulic fluid level by a photo detector.