See Figures 1, 2, 3 and 4
Upper and lower radiator hoses, along with the heater hoses, should be checked for deterioration, leaks and loose hose clamps at least every 15,000 miles (24,000 km). It is also wise to check the hoses periodically in early spring and at the beginning of the fall or winter, when you are performing other maintenance. A quick visual inspection could discover a weakened hose which might have left you stranded, had it remained unrepaired.
Both the upper and lower radiator hoses are called upon to perform difficult jobs in an inhospitable environment. They are subject to nearly 18 psi (124 kPa) at underhood temperatures often above 280°deg;F (137°deg;C), and must circulate nearly 7500 gallons of coolant an hour; 3 important reasons to have good hoses.
A good test for any hose is to feel it for soft or spongy spots. Frequently, these will appear as swollen areas of the hose. The most likely cause is oil soaking. A hose in this condition could burst at any time, when hot or under pressure.
Cracked hoses can usually be seen, but feel the hoses to be sure they have not hardened; this condition is a prime cause of cracking.
Weakened clamps frequently are the cause of hose and cooling system failure. If the connection between the pipe and hose deteriorates enough, coolant may escape when the engine is hot.
Debris, rust and scale in the cooling system can cause the inside of a hose to weaken. This can usually be felt on the outside of the hose as soft or thinner areas.
Whenever you are checking the hoses, make sure the engine and cooling system are cold. Visually inspect for cracking, rotting or collapsed hoses, and replace as necessary. Run your hand along the length of the hose. If a weak or swollen spot is noted when squeezing the hose wall, the hose should be replaced.
REMOVAL & INSTALLATION
See Figures 5, 6 and 7
- Remove the radiator pressure cap.
- Position a clean container under the radiator and/or engine draincock or plug, then open the drain and allow the cooling system to drain to an appropriate level. For some upper hoses, only a little coolant must be drained. To remove hoses positioned lower on the engine, such as a lower radiator hose, the entire cooling system must be emptied.
- Loosen the hose clamps at each end of the hose requiring replacement. Clamps are usually either of the spring tension type (which require pliers to squeeze the tabs and loosen) or of the screw tension type (which require screw or hex drivers to loosen). Pull the clamps back on the hose away from the connection.
- Twist, pull and slide the hose off the fitting, taking care not to damage the neck of the component from which the hose is being removed.
If the hose is stuck at the connection, do not try to insert a screwdriver or other sharp tool under the hose end in an effort to free it, as the connection and/or hose may become damaged. Heater connections especially may be easily damaged by such a procedure. If the hose is to be replaced, use a single-edged razor blade to make a slice along the portion of the hose which is stuck on the connection, perpendicular to the end of the hose. Do not cut deep so as to prevent damaging the connection. The hose can then be peeled from the connection and discarded.
- Clean both hose mounting connections. Inspect the condition of the hose clamps and replace them, if necessary.
- Dip the ends of the new hose into clean engine coolant to ease installation.
- Slide the clamps over the replacement hose, then slide the hose ends over the connections into position.
- Position and secure the clamps at least 1 / 4 in. (6.35mm) from the ends of the hose. Make sure they are located beyond the raised bead of the connector.
- Close the radiator or engine drains and properly refill the cooling system with the clean drained engine coolant or a suitable mixture of ethylene glycol coolant and water.
- If available, install a pressure tester and check for leaks. If a pressure tester is not available, run the engine until normal operating temperature is reached (allowing the system to naturally pressurize), then check for leaks.