Age hardening in hose causes the cracks and excessively tightening hose clamps may cause separation and tearing. A hose is soft, swollen and may be bursting, it needs replacement. Hoses may deteriorate internally if the cooling system is not regularly flushed. The upper and lower radiator hoses, and the heater hose should be examined at the least frequency of 30,000 miles, and also during early spring and at the beginning of the fall or winter. The engine and cooling system should be kept cold and during inspection, any cracking, rotting or collapse of the system should be noted and any weak or swollen areas replaced. When removing a hose, it is important to remove the radiator pressure cap first to prevent burns caused by hot coolant or steam. Place a clean container below the radiator or engine drain, open drain and then run the system accordingly making sure to place a close-top container to avoid damaging pets with ethylene glycol. Relax the hose clamps at each end of the hose and twist, pull and slide the hose off the fitting without damaging the connection. In case the hose is stuck, it can be carefully cut off with a razor blade, ensuring that the connection is not damaged. Clean the mounting connections, and check the clamps in case they need to be replaced. To install, wet the ends of the new hose in clean coolant, slip the clamps over the hose and then connect it to the connections, making sure that the clamps do not go more than 1/4 inch in any direction. Close the drains and add the coolant drained plus an appropriate mix to the cooling system. Lastly, inspect leaks with a pressure tester or by warming up the engine to normal operating temperature, taking care not to touch the hot or moving components when inspecting the fittings.