This article describes an experimental investigation to study the role of the load sensing (LS) valve on the pump performance. The effect of rotational speed, as well as the pump pressure on the overall leakage flow of a swash plate-type axial piston pump at load sensing and without load sensing, have been carried out. The case drain pressure is influenced by the leakage flow of different parts of the system, therefore the overall leakage flow depends on the pump pressure and the case drain pressure. Some factors indirectly influence the pump performance such as speed of rotation, different precompression of LS spring, and external load applied on the hydraulic circuit. Keeping in mind, that pump efficiency reduces due to unusual leakage, but it is necessary to prevent wear and tear of various parts of the pump, several experiments have been conducted. The outcomes of the experiment show that, for 1000, 1200, 1400 rpm the difference in leakage flow with LS and 100% precompression of LS spring, for 50 bar compensator pressure are 0.42 lpm, 0.55 lpm, 0.25lpm. The impact of the rotational speed, LS spring precompression and external load on the overall leakage and pump pressure. The overall case drain leakage was increased by increasing the precompression of load PRV at 14% precompression of LS is about 1.57 lpm.