Although most people generally welcome the warm days
of summer, it can mean disaster for your car. Warm-weather driving
places an extra strain on the cooling system and unless it is
operating at peak efficiency, that extra stress can mean
Avoid overheating with some simple
advice and a few quick tips. A couple of cooling system checks can
be done yourself, including checking belt tension as well as hose
and clamp condition—make sure the engine is off before attempting
Just because your vehicle isn't experiencing overheating problems
now doesn't mean the cooling system is okay. Cooling system
components—radiator, radiator cap, coolant, recovery tank, hoses,
clamps and drive belts—receive a lot of wear and tear.
Overheating caused by a faulty fan belt or a broken radiator hose
can give motorists problems in the fall and winter, though
summertime sees the most problems, almost nine out of ten radiator
hose and fan belt failures create an emergency situation, they
frequently happen far enough away from home that they increase both
the cost and inconvenience of repairs, as well as ruin a family
Drive belts, fan belts and hoses are vital parts of the cooling
system, transferring engine power to the alternator, air
conditioning compressor, radiator fan (on older vehicles), water
pump and other items. When a belt failure occurs, power cannot be
transferred to these components; the resulting battery discharge
and/or overheating can leave you stranded.
Hoses transport thousands of gallons of hot, pressurized coolant
through the radiator every hour and serve as shock absorbers between
the engine and the cooling system connections, preventing them from
possible damage. When a hose fails, boiling coolant bursts through
the fissure and without this vital cooling, the engine overheats.
So why do hoses and belts fail more often than other components?
Heat. Under-hood temperatures during summer driving often exceed 280
degrees Fahrenheit. Heat from within the cooling system and under
the hood breaks down the coolant, hoses and belts, putting a strain
on the water pump and clogging radiator and engine passages with
impurities and debris that cause corrosion. When enough degradation
occurs, any additional stress—such as low speed, high rpm driving
(as when towing uphill)—may cause overheating that can result in
major engine damage.
To avoid expensive and troublesome repairs, take your vehicle to a
qualified service center and have the cooling system checked for
potential problems. Apart from inspecting the belts and hoses for
wear and tear, the technician will check the coolant for acidity and
its ability to withstand low temperatures without freezing, as well
as the integrity of the overflow tank. He will also check the
thermostat and pressure test the system to make sure it is in good
Have the belts and hoses checked every six months or so. While you
can take the vehicle in for these checks, it's easy to do at home.
No tools are required. With the vehicle parked and the engine off,
simply lift the hood and check the hoses for cracks, bulges, splits,
hardness or sponginess. Give them a squeeze between your thumb and
forefinger. They should feel firm and pliant. Any hose that feels
hard, brittle, spongy, mushy or looks swollen should be replaced, as
should rusted, sprung or distorted clamps holding them in place.
Drive belts generally last longer than hoses, but they don't last
forever. Check for chunking, splits, cracks, or fraying and have
them replaced every 40,000 miles or two years, regardless of
appearance. The two-year rule is important because many of the
new-composition drive belts don't show any signs of wear until they
Have the tension checked when the belts are inspected. Incorrect
tension is the main cause of belt failure. A loose belt will slip,
become glazed, and won't drive the water pump or alternator. You
could end up with an overheated car and a dead battery.
Belts that are too tight usually crack on the underside and
eventually break. Tight belts put extra stress on the water pump,
alternator, and air conditioning compressor, causing them to wear
prematurely. To check belt tension, simply push down on the belt
with your thumb. (Make sure the engine is off.) The belt should flex
about 3/4 of an inch. If it moves less or more than this, get it
Coolant, a mixture of ethylene glycol and water, breaks down with
age, picking up impurities and becoming diluted. Have it changed
every two years or 24,000 miles to ensure it is in good condition.
If you do the job yourself, take care not to spill any. Coolant is
toxic and will pollute the water table. Take used coolant to a
Here are a few additional tips to help keep your car and your temper
Keep a spare drive belt, gallon of coolant, stop leak and vinyl tape
in the trunk for emergencies.
If the car is running hot, turn off the air conditioner, open the
windows and turn on the heater. It may be uncomfortable, but it will
help cool the engine.
Turn off the air conditioning when climbing long hills, especially
If you own an older vehicle or frequently drive in dusty conditions,
get the engine steam cleaned. Baked-on grease and dirt keep engine
heat in, making the cooling system work harder.