Pumping concrete is the unit’s main job, and hydraulics help to get it done. But concrete placement only happens successfully if the truck is firmly planted on the ground. The boom may reach out 100 ft or more. To keep the unit from tipping, a set of outriggers reach out from the truck much further than on most cranes. These long-reach outriggers typically need telescopic cylinders to extend them and later to tuck them away. High quality, pilot-operated check valves keep the down-cylinders locked against the ground.