The upper and lower radiator hoses, and the heater hoses, should be checked for deterioration, bulging, damage, leaks and loose hose clamps during every oil change, or once a year, or every 15,000 miles (24,000 km) whichever occurs first. Because the engine's cooling system operates under moderate heat and pressure, a pinhole-sized leak could allow enough coolant to escape quickly enough to render the vehicle inoperable. Operating an engine low on coolant, even for a short period of time, could cause very expensive internal damage. It is also wise to check the hoses periodically in early spring and at the beginning of the fall or winter when performing other preventative maintenance. A quick visual inspection could discover a weakened hose, which could have failed, and left the vehicle stranded at the side of the road, if it had remained unrepaired.
Whenever checking the hoses, make sure the engine and cooling system are cold. Visually inspect for cracking, rotting or collapsed hoses, and replace as necessary. Feel along the length of the hose. If a weak or swollen spot is noted when squeezing the hose wall, the hose should be replaced.
See Figures 1, 2, 3 and 4
REMOVAL & INSTALLATION
- Before proceeding, make sure the engine is cool. Carefully feel the engine's valve cover, and upper and lower radiator hoses to ensure the engine and coolant temperature is cool enough to proceed.
- 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 most upper radiator hoses, only a small amount of coolant must be drained. To remove hoses positioned lower on the engine, such as a lower radiator hose, the entire cooling system must be drained.
- Loosen the hose clamps at each end of the hose requiring replacement. Clamps are usually either of the spring tension type (which require a pliers to squeeze the tabs and loosen) or of the screw tension type (which require screw or a hex driver to loosen). Slide the clamps back on the hose away from the connection once loosened.
- 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. Sometimes a cotter- key removal tool can be used with a suitable penetrating lubricant spray to loosen a hose if it must be reused. Make sure the tool is free of nicks and burrs that might damage the hose. If the hose is to be replaced, use a single-edged razor blade to carefully make a slice along the portion of the hose that is stuck on the connection, perpendicular to the end of the hose. Do not cut too deep 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. (6mm) from the ends of the hose. Make sure they are located on the connection beyond the raised bead of the connector.
- Locate the air bleed valves and open the valves one full turn.
- 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.
- Close the air bleed valve once the fluid flowing from the valve is free of any air bubbles.
- 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.
- Once the engine cools, open the radiator cap and recheck the fluid level and top off as necessary.