The radiator hose clamps are made of flat spring steel that encircle the hose. A pair of pliers can be used to squeeze the tabs to expand the clamp to remove or install. The two lower radiator hose clamp each cracked and broke. After breaking, the clamps no longer keep uniform pressure and therefore allow coolant to leak. One was close to allowing the hose to push off the lower radiator tank barb fitting. If this was to happen, coolant would be lost rapidly. This would result in an engine overheat and possible damage.