You know that long belt that snakes around the front of your
engine? It’s called the serpentine belt. The serpentine belt is driven by the engine as it turns.
your alternator, air conditioning compressor, and power steering pump. On some vehicles it also runs the water
pump, radiator fan, and power brakes. Sounds like a lot of important stuff doesn’t it?
If your serpentine belt were to break on one of our St. Louis, Missouri roads, your battery would die in a few miles. If it
runs your fan or water pump, your engine could overheat. And steering and braking could be more difficult. Obviously,
the best thing is to replace your serpentine belt before it breaks.
BELTS & HOSES From February 15th through March 31, 2018
The LAST thing you want is to be stranded by a broken belt or
a blown hose. You could also do SERIOUS, EXPENSIVE damage to
your engine if it overheats!
During designated dates, Get FREE BELTS & HOSES!*
a great deal for you to be SAFE and SAVE money!
*Most Cars. Excludes carry-out. Free belts & hoses offer
requires installation at our repair shop. Installation,
coolant & additional parts, as needed, extra. Offer valid only
while supplies last. See store
for full offer details.
INSET VIDEO - Your
vehicle won't run if the serpentine belt breaks
20 percent of vehicles on the road today need a
serpentine belt replacement. A worn belt can not only break without warning, it can slip
and damage important engine accessories. Have your belt inspected and replace it if it is
worn or damaged. You'll be glad you did. At Sparks Tire & Auto in St. Charles
install quality NAPA replacement parts. Give us a call at 636-946-5900 and let us help
keep you safely and economically on the road.
Check your owner’s manual for when factory maintenance is
recommended for you belts and hoses, and/or the interval recommended to replace your serpentine belt – or just ask
your Sparks Tire & Auto service advisor for assistance. He can inspect the belt as well to
see if it’s in trouble.
You may have been told by a service advisor in St. Charles, MO. to look for cracks in your belt to see if it needs to be
replaced. Of course, cracking is still a concern, but modern belt material doesn’t crack as often as old belts did.
What we look for these days is the thickness of the belt. We have a special little tool at Sparks Tire
& Auto that measures the depth of the grooves in the belt to see if it needs replacing.
A worn belt can slip or be misaligned, putting undue stress on the accessories it runs.
INSET VIDEO - A worn, loose, or misaligned belt stresses accessories
Above is a silent animation video showing key
components that rely on the serpentine belt, such as the power steering pump, alternator
and A/C Compressor.
belt tensioner will also be checked for wear by our technicians along with the belt
itself. Other components such as a decoupler pulley on the alternator, and any tension
idler pulleys will be checked for seizing. The animation video will give you a good
indication how we check for belt wear, which involved more than just inspecting for
cracks, like we did in the older days.
Now you can imagine it’s important for the belt to be tight, so there’s a tensioner pulley on your engine that puts
pressure on the belt to keep it at the right tension. The spring on the tensioner wears out over time so we
recommend replacing the tensioner pulley at the same time as the serpentine belt.
Replacing your serpentine belt on schedule, or when an inspection warrants it, will keep you from an unexpected
What's A Serpentine Belt?
All of us in St. Charles Missouri have those days when we've got a bunch of errands to run around the St. Louis area.
Suppose on your day off you need to get gas, pick up some groceries, swing by your local St. Charles ATM and get the
kids from school. Now you could make four trips, but that would be a waste of time and money – totally inefficient.
Instead you get organized and hit the ATM first and get some gas next. Then you go to your St. Charles supermarket
and pick up the kids on the way home. Way better use of your time.
Now you may wonder what this has to do with your vehicle. Well, back in the day, each of your engine's accessories,
like the alternator and air conditioner, were powered by separate belts. A vehicle might have 5 or 6 belts. These
days, vehicles have a single belt to run all the accessories. It's called the serpentine belt because it snakes around
everything, efficiently connecting the accessories – like bundling your errands.
A pulley attached to the vehicle engine's crank provides the power to turn the serpentine belt. The belt may provide
the power for the power steering pump, which makes it easier to steer your vehicle. Next comes the alternator which
generates electricity to run the vehicle's electrical system and charge the battery. On to the air conditioning
compressor; This helps make cold air to keep you comfortable all summer long in St. Louis, Missouri.
On some vehicles the water pump or radiator fan or the power brakes are also run by the serpentine belt. Some even
have two serpentine belts. No matter how your engine is arranged, you aren't going far without a serpentine belt. Your
vehicle has a recommended interval for inspecting your belt and your technician at Sparks Tire & Auto can
inspect it for damage or wear.
Finally, there is the belt tensioner. Its job is to apply pressure on the belt to keep it tight. Several years ago,
started making serpentine belts out of a new material. It's much more durable, but it's harder to tell when the belt
needs to be replaced. The old style belts would crack and chunks would fall off so you could easily see when you
needed a new one.
On the new style belts, if the ribs wear too deep, it's time to replace. Your uses a simple gauge to tell when the
belt is worn and you need a serpentine belt replacement. A worn belt stresses your vehicle engine's expensive
accessories and causes them to wear prematurely.
So, change your serpentine belt and belt tensioner as recommended by your friendly and knowledgeable pros at
Sparks Tire & Auto to extend the life of your accessories and to prevent future breakdowns.
Sparks Tire & Auto | Serpentine Belt Service
Your serpentine belt drives your alternator and air conditioning compressor. The power steering and power brake pumps
are driven by the serpentine belt in many St. Louis residents vehicles. In some vehicles, the water pump is driven
by the serpentine belt (in others it's driven by the timing belt). The radiator cooling fan on some vehicles are also
driven by the serpentine belt. Some have separate electric motors.
Serpentine belts do a lot of work, but they're tough and can last for thousands of miles, but just how long will they
last? That'll vary for each individual Missouri car. Your manufacturer or Sparks Tire & Auto technician
will have a recommendation for when it should be changed, but it could need it sooner. The good news is that a visual
inspection can reveal a belt that's worn.
It's often recommended that the tensioner pulley that keeps the belt at the proper tension be replaced along with the
serpentine belt. This pulley is mounted to the engine block with a spring loaded arm.
What are the warning signs that there's a problem with the serpentine belt? You may hear a squealing sound from under
the hood when accelerating. A loose belt might give you a slow, slapping sound.
If you suspect a serpentine belt problem, or if it's just been a while since it was last checked, ask your friendly
and knowledgeable Sparks Tire & Auto service advisor to have it looked over.
Serpentine Belt Replacement At Sparks Tire & Auto
The following article focuses on your serpentine belt. In some vehicles, power steering may have an electric drive and
power brakes can be vacuum driven.
And, on many vehicles, the serpentine belt powers the water pump (on some cars, the water pump is powered by the
Your Sparks Tire & Auto service technician can perform a visual inspection of the belt to see if it has any
cracks that signal the belt could fail soon and will measure the amount of belt material to make sure there is enough.
Sparks Tire &
Auto drivers should be aware that there's a special, spring loaded pulley attached to the engine called
the tensioner pulley and sometimes an extra pulley call the idler pulley. Their job is to make sure there's a constant
tension on the serpentine belt so that it doesn't slip. The spring can become worn and no longer provide the necessary
pressure to keep the belt tight. That's why it's often recommended that the tensioner, and the idler pulley if so
equipped, be replaced at the same time as the serpentine belt.
All in all, the serpentine belt's an important part for the function of your vehicle. And it's not that expensive to
replace at Sparks Tire & Auto – so it's good to do so before it fails.