Hydraulic pump unit for vehicle

A hydraulic pump unit (1), for a vehicle, that is unusually capable of precise and effective bleeding, comprises a reservoir (2) for the brake fluid, a master cylinder (3) in the said pump connected to the said reservoir, and a bleed circuit (15) connected at one end to the said master cylinder and fitted with a bleed nipple (19, 119, 219, 319, 419) that is normally closed in order to shut the said circuit off, and it is constructed in such a way that the said bleed circuit (15) is connected at the other end, downstream of the said bleed nipple (19, 119, 219, 319, 419), to the said reservoir (2).