Express Car Care of Denver

"Denver's Best Auto Repair and Quick Lube"

Car Brakes 101: How They Work and How To Repair Them

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What’s the most overlooked part of your car? Yep, it’s your car brakes.

You enjoy taking your car to the carwash and driving a sparkling car. You have a little sticker on your windshield, reminding you of the need for oil changes. But car brakes? When was the last time you gave them any thought at all?

Yet they aren’t something you can ignore.Car Brakes 101: How They Work and How To Repair Them

What brakes do

Brakes don’t stop the car. Instead, brakes stop the wheels from turning, which in turn slows down the car and brings it to a stop.

Most modern cars use disc brakes for the stopping process. Disc brakes consist of:

  • Brake discs
  • Calipers
  • Brake pads
  • Brake lines
  • Brake master cylinder

Every wheel has a plate-like disc attached to it. Also called a rotor, this plate is squeezed by the brake pads within the caliper every time you want to slow down.

Brake pads have two layers: a metal backing and a high-friction material molded onto the backing plate with heat and pressure. It’s also coated with an adhesive that helps the brake pad and caliper withstand high temperatures and excessive heat buildup.

What are brake pads made out of?

If you head back in time, the original brake pads that grew in popularity during the 1950s and 1960s were made from asbestos. It was thought to be a great material because of its heat-resistance and durability qualities. However, as health ramifications were discovered, auto manufacturers looked for alternatives to make a safer product.

The organic brake pad was created from a variety of materials and fibers and mixed together with binding resins to hold them together. You might find glass, rubber, carbon, Kevlar, and other fibers mixed in. Because they are inexpensive to create, the majority of new cars are still installed with organic brake pads today. They’re easy on the brake rotors, suitable for all driving environments, and don’t require a lot of heat to generate good friction. That makes them the perfect choice in most conditions.

The metallic brake pads are manufactured with steel, iron, copper, or other metals, added to friction modifiers and fillers to create the final product. Metallic brake pads are thought to be one of the most versatile on the marketplace, being more durable and longer lasting than the organic composition.

You’ll find better braking performance, a wider operating range in heat and cold conditions, a firmer feel in driving conditions, and more resistant in the long term. But because the brake pad is created from metal, it is noisier than other brake choices, and will produce more brake dust.

The newest brake pad on the market is made from ceramic. Ceramic pads are created from a dense ceramic material – think pottery – with copper fibers added during production. They are quieter than metallic brake pads, and produce a finer brake dust which won’t stick to wheels. And because it has the longest lifespan of any brake pad, they can be a great choice if you’re investing in your car for the long term.

What causes brake pads to wear

The biggest enemy to a brake pad is heat. As the brake pad moves against the brake disc, friction occurs, and heat is produced. To remove this heat, a car is designed with several systems to prevent buildup, especially in the front brakes where more action occurs. The brake disc is ventilated to allow cooler air to be pumped in and spread to the outer edges of the disc. The more hot air is kept away from the center, the less likely the disc will “fade.”

Fading is when brakes overheat. If car brakes are continually used while overheated, brake fluid can impact the calipers, which reduces the ability to brake. You may notice this if:

You’ve had to depress the brake pedal farther to the floor

You’ve pushed the brake pedal all the way to the floor without any braking

It takes you more distance to come to a stop

You smell a burning odor during the braking process

Your brakes start smoking or catch fire

This is where higher performing brake pads come into play. While an organic brake pad will provide excellent performance in standard conditions, only you can decide how you drive. If you need better performance, talk with one of our technicians about which option is best for you.

Keep your brake system happy

While it might be a glamorous purchase, brake pads are vitally important to your car’s safety and performance. Of course, so is regular maintenance.

Like an oil change, your brake fluid should be changed regularly too. Brake fluid attracts moisture. And moisture isn’t a good thing for your car’s braking performance.

Moisture reduces brake fluid’s boiling point, which makes it easier for brakes to overheat, especially in summer conditions.

Boiling brake fluid also enhances fading, which means your brakes can fail at the most inopportune time, like driving down long hills. That can be a big problem if you’re coming home after a fun-filled weekend in the mountains.

Moisture also corrodes metal. And since your brake pads are created from metal, it can wear down or even cause your brake pads to cease long before you anticipate.

Your best bet is to replace your brake fluid on a regular basis, according to your car’s manufacturer recommendations, or every couple of years. It’s the perfect way to keep your car happy and running well no matter what type of driving you do.

While brakes may not be the sexiest piece of equipment on your vehicle, they are one of the most important. If you want to keep a well-maintained car ready for all sorts of driving conditions, the best place to start is at the bottom – with your car brakes. Well-maintained car brakes will have better braking capability and keep you and your car’s occupants safe and secure.

And that can be a very good thing, whether you’re driving home from a day of skiing, or heading to work in the middle of the summer. Make the right choice, and your car brakes will be happy for the life of your car.

Brake Rotor Problems

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Brake Rotor ProblemsDisc brakes are called disc brakes because of the big metal disc or rotor that spins with the wheel.  The brake pads rub against the rotor to slow the vehicle.  In technical terms, the motion energy of the moving vehicle is transferred into heat energy by the brakes.  The job of the rotor is to absorb that heat and dissipate it into the atmosphere.  To do that effectively, the rotor needs a certain amount of mass ( measured by the thickness of the rotor) and a good surface to mate with the brake pads.  Let’s talk about those two things.

First is the thickness.  A new rotor is nice and thick and can absorb a lot of heat and dissipate it effectively.  Over time, the rotor will wear away slightly.  If it wears away too much, there isn’t enough metal to take care of the heat transfer and the vehicle will not brake as well.  In fact, each rotor is stamped with the minimum thickness the rotor must have, when the rotor reaches this “discard thickness”, it must be replaced.

The next thing for our consideration is the rotor surface.  This isn’t just about the quality of the rotor’s surface, but also about how evenly the brake pad sweeps the rotor.  Several things can affect the “swept area” of the rotor.  A common problem is a scored or scratched rotor.  When brake pads wear past the point in which they should be replaced, metal parts of the brake can meet the rotors and grind grooves into the rotor.  Imagine putting new brake pads on a scored brake rotor.  The pad would only contact the ridges.  This can significantly reduce the contact area and hurt braking performance.  When a brake rotor has been scored, it may be able to be resurfaced on a brake lathe which smooths the surface.  If the brake rotor isn’t thick enough to be resurfaced, it need to be replaced.

Another common brake rotor problem is something called run out.  This is when the rotor is slightly off axis or crooked, so the brake pads don’t come into contact fully or evenly with the rotor.  Run out is measured in thousandths of an inch, so we are talking about very small variations that can affect braking.  Run out can be caused by a bit of dirt or rust between the brake rotor and the wheel hub, or even by slight variations in the mating surfaces of the brake and hub.  Your technician can determine the cause and take the appropriate measures to restore proper brake pad contact.

When run out isn’t detected and corrected early, the rotor itself can wear unevenly leading to thickness variations.  This condition is called parallelism because the inboard and outboard surfaces of the rotor are not longer parallel.  The variations are small, measured in 10 thousandths of an inch, but they can significantly affect braking performance because of limited brake pad contact.  This condition used to be referred to as “warped” rotors.  If the rotor is still thick enough, the brake technician will correct the underlying run out problem and resurface the rotor to restore the contact surface, but if the rotor is severely worn it must be replaced.

So, if you hear a grinding sound when you brake, or if your pedal feels unusually soft or hard, bring your vehicle in for an inspection.  We can get you the quality parts you need to fix the problem.

Tire Rotation & Balancing

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You can make the tires on your vehicle last longer with a regular tire rotation and balancing.

Let’s start with the tire rotation.  In normal driving around town, your front tires wear more on the shoulders because they handle most of the cornering forces in the turns.  If you’re driving a front-wheel drive vehicle, there is even more force put on the front tires.

The reason we rotate the tires is so that all of the tires have some duty on the front end and it also gives the back end a little break.  By doing a tire rotation, all four tires should wear more evenly over their life, this helps them last longer.

Most vehicles have their tires rotated front to back, but some manufacturers recommend a cross rotational pattern that includes the spare tire too.  If you drive a high performance vehicle, they might have different size tires on the front and rear, or they may have unidirectional tires that can only be on the left or right side of the vehicle.  If you drive this type of vehicle be sure to ask your service adviser to help you figure out just the right tire rotation for your vehicle.

Tire manufacturers always have recommendations for how often they want you to rotate your tires.  These recommendations usually fall somewhere around 5,000 to 8,000 miles or 8,000 to 13,000 kilometers.

Now let’s talk about wheel balancing.  Balancing is when there are heavy spots on the tire and wheel that causes it to wobble.

Wheel balancing is adding weights to the wheel that balance it out so it doesn’t wobble.  These are very small weight differences.  There are variations in tire and wheel manufacturing that can cause slight imbalances.  The valve stem and the tire pressure monitoring sensors in the tire can also make a difference.

Even small differences can cause annoying vibrations.  The wheel is basically bouncing as it travels down the road.  Say you were driving on the freeway, if your wheel is out of balance it can slam into the road 14 times a second.  Besides being annoying it also causes your tires to wear out quicker.

If you have a front wheel out of balance, you’ll feel a vibration in the steering wheel, and a rear tire will vibrate your seat.  If you have any type of vibrations in your vehicle, come in and see us.  We’ll see if it’s a balance issue or another problem.

EGR Valve

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Have you ever stopped to think how amazing it is that auto makers have been able to consistently build more powerful engines in vehicles that get better fuel economy while at the same time meeting increasing environmental standards.  One of the little miracles that helps make this happen is the Exhaust Gas Recirculation Valve or EGR Valve.

The EGR valve routes some exhaust back into the air intake system in both gasoline and diesel engines.  The exhaust gas takes up some space in the engine cylinders, replacing some of the oxygen-rich air that would otherwise be in there.  This means that the fuel burning event is cooler.  Cooler combustion means fewer harmful nitrous oxides are produced.

Your EGR valve can get gummed up, messing up the timing and the amount of exhaust that is supposed to be recirculated in the engine.  Symptoms of EGR valve problems are a rough idle and poor engine performance.  Performance can be restored by cleaning or replacing the EGR valve, depending on how dirty it is.

EGR valves in diesel engines are particularly susceptible to becoming clogged because of the high soot content in diesel exhaust.  ( The soot is ultimately filtered out of the exhaust further down the exhaust system, but not before it passes through the EGR valve).

There are a couple of things you can do to lengthen the life of the EGR valve in your diesel engine.  First, extended idling allows for more soot buildup because the engine operating temperature is reduced as it idles; the valve is not opening and closing, allowing particulates to accumulate in the valve.  Next is fuel quality.  Diesel fuel has a cetane rating:  the higher the rating, the better the combustion.  Unfortunately, the cetane rating is rarely posted on the pump and can vary from location to location.  Adding a cetane booster to the fuel tank can help with this problem.

So, if you’re experiencing rough idling or poor performance in your gas or diesel vehicle, have one of our Express Car Care technicians diagnose the problem.  They can set things right and restore your vehicle’s performance.

Engine Air Filter

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Today we want to talk about your engine air filter.  That’s the filter that cleans the air before it’s burned in your engine.  Many people wonder how often they should change their engine air filter.  The simple answer is ” when it’s dirty”.  That’s a function of how much air has passed through the filter, so your vehicle manufacturer will recommend a mileage interval for replacing the air filter.  But it’s not hard to imagine that how dirty the air is will greatly affect how quickly the filter gets filled.

If you drive in a city or town where there’s lots of dust, pollution, or pollen, your engine air filter will get dirty more quickly and will need to be changed sooner.  That’s why we check the air filter with every full-service oil change at Express Car Care.  We can visually tell if the filter needs to be changed.

Your filter can only hold so much dirt.  Once the filter is full, dirt will pass through to the engine.  This dirt gums up the combustion chamber, hurts fuel economy and may cause damage.  It can also contaminate the Mass Air Flow Sensor, which will affect drivability and can be fairly expensive to replace.

A dirty engine air filter would also restrict the amount of air that gets to the engine, which diminishes fuel economy.  We can replace your air filter with one that matches the factory specifications or you can choose to upgrade your filter for enhanced performance.

So the next time your service adviser at Express Car Care shows you your dirty air filter, remember how important it is to have it replaced.

Suspension Wear

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Your suspension system keeps your car up off the road.  From there, it’s responsible for a smooth and comfortable ride wherever you choose to drive.  It also keeps your wheels firmly planted over bumps and through curves.

Your suspension system has many critical parts that do a big job and because of of that, they should be inspected for suspension wear or damage at least once a year.  A good time to check for suspension wear would be when you get your semiannual alignment check.

Here are some warning signs of suspension problems:  the car pulls to one side, wandering, erratic steering, uneven tire wear.  You could also experience leaning, shocks bottoming out, a poor ride or handling, leaking oil from the shocks and excessive bouncing.

Unfortunately, suspension parts just wear out over time.  Shocks and struts eventually lose their ability to control your ride.  If you’re in an accident, your suspension can be damaged or knocked out of alignment.  Even a minor accident, like hitting a curb, pothole or large rock, can mess things up.  If you suspect suspension problems, ask a trusted service adviser at Express Car Care for an inspection and let us set things right.

Give us a call or come in and see us.

At Express Car Care we install quality NAPA replacement parts.

Most Stolen Item?

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What do you think is the most stolen item from vehicles?

Is it:  (A) Stereo  (B) Wheels  (C) Airbags  (D) DVD System

Well, if you said stereo – you used to be right.  But now airbags have surpassed stereos as the most stolen item – approximately 50,000 a year are stolen nationally in the United States.  New airbags cost about $1,000 but stolen airbags are sold on the black market for $50 to $200.  Stolen airbags are finding their way into vehicles that have been involved in an accident.    Of course, the danger to the consumer of having a stolen airbag installed is that you can never be sure what may have previously affected them and if they will work correctly when you need them.

There have been reports that 1 in 25 airbag replacements are either stolen or salvaged airbags – or no airbag is installed at all.

That is definitely a part that you don’t want to take a chance with, so we recommend the following guidelines:

  • Use a reputable collision repair center that employs ASE certified mechanics.
  • Inspect the invoice to ensure that the repair shops purchased the airbag from a manufacturer, or dealer.
  • If you can inspect the airbag prior to installation, it should be packaged in a sealed container from the manufacturer or dealer.

You will see the SRS ( Supplemental Restraint System) light come on when you first start your vehicle.  This tells you that the airbag system is activated,  If you don’t see the SRS light, there is a problem with the airbag system.  Have the system checked right away and don’t let yourself become an injured victim.

Don’t Be A Stranger

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You wouldn’t walk into a different dentist’s office every time you needed your teeth cleaned.  You wouldn’t pick someone at random every time you needed your hair cut, would you?  And on tax day, would you trust your taxes to a stranger?

There are some professionals for whom you feel your relationship is more than just client and customer.  They’re almost like friends…and since you know them well after years of going to them, you know the quality of their work and that they have a track record of doing their best for you.

You may not realize it, but the relationship with your automotive service professional should have that personal connection too.  It may take some time to find the one place where the rapport just feels right.  But when you do, you know as you walk in the door, and your service adviser greets you with a smile, things are going to be done right.  You’re also confident that they’ll only recommend and perform work that your vehicle really needs.

Just as with your hairstylist, accountant, or lawyer, the relationship with Express Car Care is a two-way street.  The longer we get to know you, the more we understand your needs and expectations of us.  We’re no longer strangers.  You get to know our work, our professional ethics and the quality of our work.  That mutual trust if something we both value.

People who have been in business for a long time know how important that long-term relationship is, that’s why we hire and train professional technicians who take their job and training seriously…but also recognize the human side of automotive repairs and trust.

So, don’t be a stranger.  It’s a relationship that is a win-win for both of us.

Give your friends at Express Car Care a call for all your automotive needs.

Battery Replacement

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Car batteries wear out just like any other battery and need to be replaced.  There are a couple of things vehicle owners should know when looking for a battery replacement:  one is cold cranking amps and the other is reserve capacity.

Let’s start with cold cranking amps.  This can be thought of as the power serge used to start a cold vehicle engine.  The number of cold cranking amps you need depends on your vehicle and where you live…specifically how cold it is where you live.  The two factors being that the colder an engine is, the more power it takes to turn it over and get it started.  It has a lot of cold, sluggish oil to fight against.  The other factor is that the chemical reaction in the battery that creates electrical energy is less efficient in the cold.

So the colder the weather gets, more power is needed, but less is available.  If you live where it’s cold, you need a battery replacement with more cold cranking amps than you would where there are moderate or hot temperatures.  You should always get at least as many cold cranking amps as the manufacturer recommends but you may want to upgrade if you live where it gets real cold.

An important note:  Batteries may also list the Cranking Amps-CA -number.  It is the Cold Cranking Amps – or CCA – that is the important number here.  CCA is the number to use in your comparisons.

After all this talk of cold temperatures, it’s important to note that heat is the real enemy of long battery life.  In other words, the damage that’s done over the hot summer months shows up with the increased demands on the battery when the weather turns cold.

Now let’s talk about reserve capacity:  It’s the measurement of the number of minutes of reserve power the battery has at a given load.  The number is more important these days because of parasitic drain.  Parasitic drain is the battery energy that’s used when the key is off.  So the power drawn by the vehicle security system, the remote start system – even the power the vehicle computers require to maintain their memory.

Reserves are also needed when you make very short trips around town.  You’re not driving long enough for the battery to recover the energy it used to start the engine.

So go with the minimum recommended by your manufacturer and upgrade if you need more.  Talk with your Express Car Care service adviser about options.  If you need more from your battery replacement, a larger capacity battery may be the answer.

Batteries are a big ticket item for most motorist, so the warranty gives peace of mind.  Be sure to ask about the car battery warranty so you know what you’re getting.  At Express Car Care, we have been providing quality auto service since 2000.  Come in and see us.

Simple Answers About Selecting Tires

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Question:  I need new tires, but how do I know which tires to select?

Express Car Care Answer:  Let’s look at selecting new tires in light of three factors:  Function, Fit, and Value.

Function:  This deals with what your needs are for new tires.  Weather conditions, terrain, temperatures, etc.

New family vehicles sold in Colorado come with all-season tires.  They can be used all year long and do pretty well on average road conditions – but they aren’t ideal in extreme conditions.

Winter tires have a more aggressive tread for handling snow and ice and they have a rubber compound that helps them have better traction as temperatures drop below 45 degrees Fahrenheit/ 7 degrees Centigrade.  In Colorado winter weather, that means better stopping and road-holding characteristics for driving than all-season tires.

Dedicated summer tires enhance warm weather performance driving.

If you drive off-road in the foothills and mountains around Denver, there is a spectrum of tire choices, from all-terrain ( a good mix of highway and off-road capability) to dedicated off-road tires.

The key to selecting tires is to discuss the function you’re looking for with your tire professional, so you get the type of tire, load rating, speed rating and wear rating you need.

Fit:  The easiest thing is to select tires in the same size that were installed at the factory.  If you want a different size wheel or tire profile, be sure to work with a professional that can make sure that your new wheels and tires fit properly and don’t rub when your vehicle bumps or turns.  It’s also important to make sure that safety systems like anti-lock brakes, stability control and traction control aren’t adversely affected by the new tire size. ( The computer may need to be recalibrated in order to make the necessary adjustments.)

Value:  Notice I didn’t say price.  The tire that meets all your needs and has the warranty and tread life you expect will probably not be the cheapest option – but it may well return the best value for your tire dollar.

Your friendly and helpful Express Car Care service adviser is ready and willing to discuss the options with you before you make this automotive decision.

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Suspension

Transmision Service

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