Reader Question Thank you for your website, it is very helpful. I always feel that i am vulnerable when I have my vehicles worked on because i do not know as much about auto maintenance as I need to and I am tired of feeling that way.

I have a 2004 Pontiac Grand Am that shows all the symptoms of worn out brakes according to your website. I took it to a mechanic and they said that not only do the brake pads need to be replaced but also the rotors. I have trouble beliveing that my car (at 37,000 miles) already needs to have the rotors replaced.

Basically all that it does now is the squealing noise except when i apply the brakes and then there is no noise. How would i know if my rotors needed to be replaced as apposed to just “trued”? Also, assuming that my rotors do need to be replaced or worked on why am i having to do that already? I have only had to do brake work on only one other vehicle that i owned and that was at the recommended 60,000 miles not 37. Is there something else that may be causing me to have to do this kind of repair prematurely?

I would really appreciate your help!

Thank you ,
Amanda

Hi There Amanda,

Thanks for your email. You might want to get a second opinion on your rotors, you are correct the mileage is low to warrant replacement, but a set of brake pads that are worn out and have metal showing only takes a few seconds of metal to metal contact with the rotor to damage them beyond the point of truing.

If you hear the brake noise with your foot OFF the brake pedal, you are probably hearing the “brake wear indicators”. This wear indicator is a thin piece of metal attached to the brake pad. When the pads wear down, the indicator comes in slight contact with the rotor, causing a vibration and a high pitched squeal. When you step on the brake pedal you force the wear indicator against the rotor and no vibration occurs or squeal noise.

If you hear a brake noise when you step on the brake, it is probably due to the metal rivets in the worn out brake pad coming in contact with the rotor….and this only takes a few seconds before sever rotor damage occurs.

If you feel comfortable with this shop, I would ask them if they “checked the rotor thickness” to see if it would be under specifications after they trued it. If all else fails, have them install new brake pads and true the rotors the best they can. The worse thing that can happen is there will be a slight vibration (rotor warp) and the brake pads might not last quite as long…but it would be cheaper than new rotors.

Blessings,
Austin Davis

Reader Question Hi Austin,
I came across your webpage while searching the Internet to find out why one needs to bleed the brakes.

I have a 2003 Honda Accord (with ABS) and I have been having this one issue for a while now and I have not had any luck with any of the mechanics (including the dealer). Problem is when I step on the break pedal, break does not respond to first inch or so – the pedal feels really soft. Then after that the it break really hard and suddenly.

I was thinking that there might be some air/moisture in the break line and maybe thats what is causing the problem – if thats what water and moisture do?

I have other cars and I brake very smootly on other cars but on this car I have never been able to get use to this car’s breaks. Even the passengers complain that I am break too hard.

I am not sure if I have explained the problem clearly or not as I am not too good at explaining things

Any feedback from you would be greatly appreciated.

With best regards,
-uday

Hello Uday,

Thanks for your email. I have seen/felt this complaint before on an Acura at my shop. The problem with that car was the brake master cylinder was faulty, we replaced it and the problem went away. I have also seen a similar complaint with a Chevrolet truck, and we replaced the two front brake calipers and brake hoses, and the problem went away.

Air can become trapped in the brake system, but it can really only get in there if there is a brake fluid leak somewhere…you would be loosing fluid, and eventually the brakes would stop working all together. Or after your last brake job the mechanic did not “bleed” the brakes properly…but that would mean the problem would have shown up right then.

Bleeding the brake system is just letting air, that was introduced when the brake system was worked on, out of the system. There are bleeder screws on each wheel that allow the mechanic to open up and allow the brake fluid to drain out…pushing out the air.

Air in a brake system usually makes the brake pedal very low, you really have to push the pedal down a long way before the brakes begin to work. This happens because you have to push the air out of the way of the brake fluid before the brakes work. I don’t think that is the complaint you have.

I would first start by inspecting all four brakes, and make sure all the brake pads and shoes look ok. If things look ok, I would replace the brake master cylinder. The brake master cylinder on this car is pretty inexpensive, and if this problem really bothers you, I would take a guess and replace the master cylinder.

Keep me posted.

Blessings,
Austin C. Davis

Follow Up
Hi Austin,

Thank you VERY MUCH for replying to my email and the time you took to explain the different scenerios in so much detail.

Though I did not do a good job of explaining, You nailed the problem exactly when you wrote “Air in a brake system usually makes the brake pedal very low, you really have to push the pedal down a long way before the brakes begin to work.” because that is what I was trying to describe.

Taking your advice I inspected all 4 breaks (pads etc) and they all looked fine. Then I replaced the break fluid and bled the system and since then the breaks have been like “normal” breaks – smoother and predictable.

I REALY want to THANK YOU for your help.

If you ever have ANY computer related question please feel free to contact me and I will do my best to help you out.

With best regards,
-uday

Reader Question:
We have a 2005 Acura RL with 22,000 miles on it. Since we bought it, we have experienced brake squealing almost every morning when we first start to work, or after letting it sit for multiple hours while shopping. The Acura
dealer has tried to tell us that the brakes are high performance, ventilated disc brakes. With more brake surface area, they are prone to occasional squealing.

To try and satisfy our complaints, the dealer has replaced and recoated the front brakes, and is currently working on replacing and recoating the rear brakes.

Is what the dealer telling us true? Are we going be listening to squealing brakes for as long as we own the car? What are our options?

Thanks,
Jim

*****************************************
Hi Jim,

Thanks for your email. I feel your frustration! As a shop owner, I sometimes get as frustrated as my customers do with brake squeal problems on their vehicles. Sometimes we just can’t seem to make the squeal go away.

First off, have you read my article on this issue?
http://www.myhonestmechanic.com/articles/brake_noise.shtml

Until the brake pads heat up (usually the third or so stop sign), many create high-pitched squeals and squeaks. Once the pads are hot, for the most part, the squeals usually go away. The noise is generally due to the small metallic flakes that are in the brake pads. “High performance”
usually means the pads are harder and contain more metallic flakes. They last longer and can handle more heat than regular pads can. Your vehicle is probably equipped with this type of pad because of the heavier vehicle weight…and the Acura’s assumption that the driver will want this added braking performance.

The kind of brake squeal you mentioned is what I would consider “normal,” and is probably something you will have to live with, but you might want to try a few of the aftermarket brake pads and see if that helps. (I almost always recommend using dealer pads, but if you are having trouble with them, you might as well try something else.)

I personally had a Ford Explorer a few years ago that had this same problem, and we tried everything to get rid of that squeal. I finally just admitted defeat and lived with it. Since then, there have been great improvements in aftermarket brakes, and there might be one that will solve your complaint.

If you are interested, visit your local auto parts store and ask them about what brake pads are available for your vehicle that are specifically made for squeaks, squeals, etc. Bendix and Raybestos both make “quiet” versions of their brake pads. I do not know what is available for your specific vehicle or what brands are available in your area, but you local auto parts guys should be able to recommend something tailored for you.

I don’t think I would have the dealer install them, they will say it will “void your warranty” blah blah blah…it’s just a set of brake pads! Any local mechanic can install them for you, but I would save your old pads just incase they are better.

Keep me posted.

Blessings,
Austin C. Davis

Do I need to flush my
brake fluid?

Reader Question:
I brought my 2000 Chevy S10 for a routine oil change. I got talked into
having my brake fluid flushed at a cost of $89.00. The mechanic said it
was dirty and needed flushing because of the ABS anti-locking brakes. I
told him I never heard of that before. My truck only has 23k miles on
it. Was I ripped off?
Thank you,
Joseph

Dear Joseph,

I know you must have been a little
surprised to hear your truck needed to have the brake fluid replaced.
But actually, this mechanic was probably doing you a good deed. Brake
fluid attracts moisture, and this moisture can rust the insides of the
brake system. This moisture was not that big of deal 10 years ago, but
on ABS brake systems of today, the rust and other debris that
accumulates in the fluid can do lots of internal damage, and can be very
costly. Brake fluid can also break down over time from excess heat that
is created from within the brake system.

At my shop we recommend flushing the
brake fluid system about every 30,000 miles, or whenever we are
performing a brake job. To do this flush, we open the brake lines
located at each wheel and allow the brake fluid from the brake master
cylinder to "gravity bleed" as we continue to feed new fluid
to the master cylinder until the fluid runs clear at all wheels. By
gravity bleed I mean without the assistance of anything other than
allowing the fluid to slowly drip from the lines by the natural force of
gravity.

You are probably familiar with the term
"bleeding the brakes" when talking about a brake job. When the
brake lines are opened or any work is performed to the brake system that
can allow air to get trapped within the lines, the brakes must be bled
of air. In the earlier days, the mechanic would bleed the brakes by
having someone pump and hold pressure on the brake pedal as he opened
the brake lines located at each wheel. This method of bleeding the
brakes is not a recommended procedure for newer brake systems (discussed
later).

What is the difference between
flushing and bleeding? Flushing is just that, flushing the old
dirty fluid out of the system and replacing it with new clean fluid.
Bleeding usually consists of removing just enough brake fluid to get out
the air pockets that have become trapped in the system, and usually does
not focus on the time consuming process of removing the dirt and old
fluid from the system.

One side note learned by experience. If
you are interested in doing a brake fluid flush on your own vehicle, be
warned of the potential dangers. Foremost, follow the brake bleeding
procedures outlined in the repair manual you should be using. Stepping
on the brake pedal with the brake lines cracked open can cause the dirt
and debris to be pushed into the body of the master cylinder, thus
causing damage to internal parts and seals of the master cylinder and
the anti-lock brake components. Stepping on the brake pedal as someone
under the vehicle opens each brake line at the wheel used to be the way
you bled brakes, but not anymore.

Gravity bleeding does take a little
longer to perform and can require a lot of new brake fluid to push out
the old dirty fluid, but the risk of doing internal damage to the
anti-lock system is greatly reduced. They also make vacuum assisted
brake bleeding and flushing equipment to help speed up the process.

How can you tell if your vehicle
is due for a brake fluid flush? They make special test strips
which can detect high levels of moisture present in the brake fluid, but
I prefer the old fashioned eye ball method personally. Remove the brake
master cylinder cap and visually inspect the condition of the fluid. Brake
fluid should be clear or a slight yellowish tent, so black or dark
colored dirty fluid should be quite obvious even to the untrained eye.

Reader Question: I just had my disc brakes replaced and they are now squealing. My mechanic says this is normal, why did I have to pay for normal squealing disc brakes? Is he just blowing me off?
Thank You,
Arnold Wrightson

Dear Arnold,

This unfortunately can happen more than you or I want it to. A certain amount of high-pitched brake noise is considered “normal” these days because of the harder semi-metallic disc brake pads that are used on cars now. In my experience, the smaller cars like Honda and Toyota seem to have the most trouble with this. Squeals heard the first few stops in the morning when the brakes are cold and somewhat damp from dew, and squeals that are heard the last few feet while coming to a stop are usually nothing to worry about.

Semi-metallic brakes are made of bits of metal shavings in place of the asbestos material that has been banned by the U.S. government. These semi-metallic brakes have great stopping power and have a long wear life, but can cause a high-pitched squeal that drives car owners crazy and frustrates mechanics who can’t get it to go away to please their customers.

When are squeals not a problem?
Some brands of semi-metallic pads are inherently noisier than others because of the ingredients used in the manufacture of the friction material. Think of it this way, the longer life pads or pads that claim to have more stopping power usually contain more metallic material. Yes, they will last longer and could enhance braking but the chance of causing a squeal noise is very high. The squealing noise that might be caused from use of these pads does not affect braking performance and does not indicate a brake problem.

Brake squeal is caused by vibration between the brake pads, rotors, and brake calipers. Having the brake rotors refinished or trued (machining a small layer of the metal away from the disc brake rotor to make it smooth and “true” again) and a thin layer of a silicone compound placed on the back of the brake pads are a great way to reduce the squeal if the semi-metalic pads are the culprit of the noise and not due to a worn out disc brake pad.

Why does this squeal happen anyway?

The brake rotor is the round metal object that the brake pads squeeze together like the white part of an Oreo cookie. The rotor is metal and has a smooth slick finish, and the brake pads are made of metal shavings and also have a smooth somewhat slick finish. The more metallic material found in the pad the greater the chance for noise, and vise-versa.

The other type of brake pad is called organic. There is no metallic material used in this kind of brake pad. Organic style brake pads can only be used on vehicles that are specifically designed to use them. Improper use of organic pads on a vehicle designed to use semi-metallic can severely reduce stopping ability. Organic pads are softer than semi metallic and usually do not have a squeal problem. Unfortunately due to shorter life expectancy, inability to stop larger vehicles, and the addition of substances like asbestos in their construction, they are not very widely used.

When are squeals signaling a problem?
Sometimes brake squeals are an indication that maintenance is required. Some common conditions that cause brake noise are:

1. Heat cracked or worn “un-true” rotors

2. Rough finish on resurfaced rotors

3. Loose fitting brake pads in the brake calipers

4. Lack of silicone compound on back of brake pad

5. Missing springs or anti-rattle clips that should be on the caliper or pad

6. Improper tightening sequence of lug nuts or caliper hardware

7. Contamination on the brake pad i.e. brake fluid or grease

Most GM cars are equipped with a small thin piece of metal attached to the brake pad to act as a warning indicator when the pad material is getting low and the brake pads should be replaced. This inexpensive warning device can be deceiving though, because this warning noise is present when the brakes are not depressed. When the brakes are applied, the warning noise goes away because the indicator has now been forced against the brake rotor and is not able to vibrate which causes this whistling noise.

If you hear brake noises other than a squeal, it could mean your brake pads are worn out and need to be replaced. If your brake pedal feels different than normal or if you’ve noticed any change in the way your vehicle brakes (pulls to one side when braking or requires more pressure on the brake pedal), or loss of brake fluid have the brake system inspected at once.

What should I do?
What can you do as a customer to reduce the chance of squealing brakes? First of all, noisy brakes should always be inspected to make sure there isn’t a problem with the braking system. If the pads have worn down to the point where metal-to-metal contact is occurring, your vehicle may not be able to stop safely, and you may damage the brake rotors or drums to the point where they have to be replaced. Sometimes a few harder-than-normal stops can “de-glaze” the brake pads and help reduce the squealing noise for a while.

There are many aftermarket brake pads that claim to be “quiet” or have been “designed” for import and front wheel drive vehicles that you can choose from. Personally, I have had the best luck replacing the disc brakes on small vehicles like Honda and Toyota with original equipment pads from the dealership rather than using aftermarket brands. It is usually more expensive to purchase these pads from the dealership, but the quality is much better. I am an independent shop owner and my whole business philosophy is to buy as little as possible from dealerships, but after trying many squealing aftermarket brake pads, I have learned my lesson and pay the extra money.

Reader Question: I bought a 2002 Camry last February and now the steering wheel is vibrating whenever I slow down or come to a stop. The tire pressure is okay so what could be causing this to happen?
Thank you,
Rita

Dear Rita,

Actually I get this question a lot and it seems to bring on more questions than answers, so let me try to explain what is going on with the help of some illustrations. The steering wheel is vibrating because the front brake rotors are warped (we call this vibration “shimmy”). Ok, this is where I usually lose people…rotors? Warped? What does this have to do with the vibration in the steering wheel? So let me explain it this way.

Let’s say the disc brake rotor is like the white center part of an Oreo cookie, and here is a picture of a brake rotor
This disc brake rotor is what the brake pads grab to stop the car. Let’s also say the brake pads are like the two dark outer pieces of the same Oreo cookie (I am starting to get hungry), and the brake caliper holds the brake pads, one on either side of the brake rotor. Here is a picture of the disc brake rotor and the disc brake caliper that holds the brake pads. When you step on the brake pedal inside the car, brake fluid is sent to the brake calipers causing hydraulic pressure to squeeze the brake rotor in between the brake pads.

So what causes the rotor to warp? The brake rotor can become “warped” or have an uneven or high spot on the surface due to normal wear and tear. It can also warp because of expansion and contraction of the metal disc rotor due to driving through a puddle of water on the exit ramp after a long trip on the freeway then applying the brakes, or due to severely worn out brake pads that have been grinding metal to metal on the brake rotor, thus cutting grooves in the rotor surface.

So what can be done to correct this problem? The brake rotor can be removed from the car and “trued” where the mechanic uses a special piece of equipment to shave off a small layer of the brake rotor to make the surface smooth and “true” or even again. Here is an illustration of the truing process . The brake rotor will have a limit to how much of the material can be removed or shaved off, and this minimum thickness is stamped on the rotor for the mechanic to see. If the rotor is below minimum thickness specifications, it will have to be replaced.

How does this rotor warp cause the vibration in the steering wheel? When the brakes are applied, the caliper and the brake pads squeeze the rotor which causes the car to stop. Remember the brake rotor is turning the same speed as the wheel. If the rotor surface is warped, the brake pads will pulsate inside the caliper as they come in contact with this high spot. The pulsating will cause the wheel to shimmy or vibrate, and this vibration can be felt inside the car in the steering wheel if the warped rotor is on the front of the car. The vibration is usually felt when applying the brakes in a panic type situation at freeway speeds, and can also be noticed when coming to a final stop like at a stop light.

Does rotor warp cause damage to my brake system? It can cause some damage or premature wear to the brake system, but most importantly it can cause a safety issue due to loss of control and full stopping power at freeway speeds, and can cause the anti-lock braking system to not work correctly. Your mechanic should inspect the condition of the brake rotors when he inspects the brakes, but if you are experiencing rotor warp be sure to tell him specifically that the problem exists. A visual inspection might not always determine a brake rotor is warped and in need of truing.

Blessings,
Austin Davis