A mud pump is a type of reciprocating positive displacement pump that is specifically designed for use in drilling operations. It helps to circulate the drilling fluid (or “mud”) through the drill bit and back up to the surface. The mud pump also provides pressure to keep the drill bit from becoming plugged. Mud Pumping: Mud pumping is recognized when the soil slurry ejects out through the joints and cracks of cement concrete pavement caused by the downward movement of the slab under the heavy wheel loads. Pumping is noticed just after the rains in cement concrete pavements that are placed on clayey soil subgrade.