Excavator comprising at least: - a frame, - a platform on top of the frame, - a hydraulic circuit assembly including at least: - a main pump delivering pressurized fluid - a number of hydraulic actuators (22, 26, 30, 50, 48, 52, 54, 56, 58) - a hydraulic distribution system for distributing pressurized fluid from the main pump to the various hydraulic actuators according at least to a hydraulic pilot circuit comprising at least one manually operated hydraulic pilot valve unit (64, 66, 68, 70) connected to the hydraulic distribution device, and wherein: - the hydraulic distribution system is received on top of the frame but below the platform, while the pilot valve unit (64, 66, 68, 70) is at least partly received on top of the platform, - the pilot valve unit (64, 66, 68, 70) is hydraulically connected to the hydraulic distribution system by hydraulic pipes; - the platform comprises a dedicated hole (86, 94, 98) capable of receiving therethrough at least that part of the pilot valve unit (64, 66, 68, 70) which is received on top of the platform; - the pilot valve unit (64, 66, 68, 70) is fixed, directly or indirectly (88, 96, 106), on the platform such that the unit or the hydraulic pipes extend through the hole; wherein the pilot valve unit (64, 66, 68, 70) can be mounted from below the platform, through the dedicated hole, and is fixed on the platform from above the platform, characterized in that the pilot valve unit (64, 68, 70) is blocked downwardly with respect to the platform by a key part (88, 96) which can be inserted from above the platform between a downwardly facing surface of the pilot valve unit (64, 68, 70) and an upwardly facing surface of the platform. - a frame, - a platform on top of the frame, - a hydraulic circuit assembly including at least: - a main pump delivering pressurized fluid - a number of hydraulic actuators (22, 26, 30, 50, 48, 52, 54, 56, 58) - a hydraulic distribution system for distributing pressurized fluid from the main pump to the various hydraulic actuators according at least to a hydraulic pilot circuit comprising at least one manually operated hydraulic pilot valve unit (64, 66, 68, 70) connected to the hydraulic distribution device, - a main pump delivering pressurized fluid - a number of hydraulic actuators (22, 26, 30, 50, 48, 52, 54, 56, 58) - a hydraulic distribution system for distributing pressurized fluid from the main pump to the various hydraulic actuators according at least to a hydraulic pilot circuit comprising at least one manually operated hydraulic pilot valve unit (64, 66, 68, 70) connected to the hydraulic distribution device, - the hydraulic distribution system is received on top of the frame but below the platform, while the pilot valve unit (64, 66, 68, 70) is at least partly received on top of the platform, - the pilot valve unit (64, 66, 68, 70) is hydraulically connected to the hydraulic distribution system by hydraulic pipes; - the platform comprises a dedicated hole (86, 94, 98) capable of receiving therethrough at least that part of the pilot valve unit (64, 66, 68, 70) which is received on top of the platform; - the pilot valve unit (64, 66, 68, 70) is fixed, directly or indirectly (88, 96, 106), on the platform such that the unit or the hydraulic pipes extend through the hole;