When Should You Change Your Brakes?

You might want to change your brakes when you come to a stop and feel a roughness. Are you hearing grinding and squealing? Have you noticed black dust around your wheels lately? If you have experienced any of this, you more than likely need to change your brakes.

You might be noticing that your car just doesn’t seem to be stopping as well as it did. There may be a burning smell when you get out of the car. If the question, “When should I change my brakes”, popped in your head, pay attention. Normally these kind of symptoms mean you need to change your brakes, but not always. Many shops are going to tell you yes, then drop a $900 invoice in your lap. Although, these signs are strong towards needing brakes, lets look into further.

Brake Systems

Brakes are simple, yet complex, and as vehicles have progressed over time, the technology behind them can blow your mind. In some ways, the saying, “ignorance is bliss” might apply here. There are many flavors of brakes. “Basic Hydraulic — (Manual or Power)”, “Anti-Lock,” “Hydro-static,” “Pneumatic” and even “Computer Controlled Electronic Brakes”.

“Anti-Lock-Brakes” started off with a more manual type controller. Now they’re completely controlled by a computer. The days of getting your buddy to pump the brakes while you bleed the them, won’t work like it did. A lot of vehicles have to be power bled. Basically a machine that pushes the fluid through the system. Depending on the type of braking system you have, you may have to turn the key on to bleed them.

With the different types of brake systems, means a variety of different issues with each system. However, the method of braking is still the same. No matter what type of system actuates the actual brake, the operation is pretty much the same. When you push the brake pedal, you are controlling an actuator. A device that moves the pads or shoes against a surface to increase resistance. This could be brake fluid, which is the most common, flowing through lines. The pressure builds up to 900 to 1400 PSI, to make the calipers squeeze the brake pads against the rotor. If you have drum brakes, then wheel cylinders push the shoes out into the drum.

Change your brakes

when should you change your brakes

 

So How Do You Know?

So when should you change your brakes? How do you know when your brakes are getting to the point of not working? Most people are not going to pull off the wheel and inspect their own brakes. Not everyone knows how and not everyone has it in their budget to have their brakes looked at regularly. Visual inspection is the best way. However, it isn’t always feasible to run down to a shop or make frequent visits. It can get expensive to pay the ridiculous inspection fees all the time to monitor your brakes. We live in a fast pace, busy world. So to incorporate mental markers for maintenance checks could be a great idea.

First thing you need to know, how fast do your brakes wear out. This depends on your driving habits. How do you drive; are you hard on the brakes; you like to go fast and stop even faster? Are you one of those that lets off the gas half a mile away and coast up to the light? Do you drive in bumper to bumper traffic every day, or is your commute cruisin’ down an open highway? These things really matter for the life of the brakes. You also have to look at what kind of quality brake pad or shoe you have on your car. If you are driving a vehicle that still has the factory OEM brakes on it, that is top quality material. You can get up to 60,000 miles or more on them, depending on your driving habits.

By Taking A look

Do a visual check for brown and black dusting around your wheel. This is a sign that your pads need to be inspected. If you have an aluminum sport wheel that you can see the brakes through, take advantage of this. Look at your rotors and look for groves, discolorations, or ground up metal marks. Drum brakes can’t be inspected visually like this, they require some disassembly for inspection.

Other indicators would be like the car not stopping like you remember it doing before. Strong smells when you come to a stop or get out of the car. Always pay attention to the ground when backing out of where you parked. If you see wet spots on the ground and not sure what it is, always check your brake fluid. Also, your brake fluid level can be an indicator if your brakes are worn. As disc brake pads wear, the fluid compensates for the wear in the pad. This will lower cause the brake fluid level to drop in the master cylinder. 

 

When to start looking at your brakes

Without any disassembly of your wheels or brakes for a visual inspection, you can follow these scenarios:

  • Starting from factory brakes. — An area where with heavy stop and go traffic or you always heavy on the brakes. Estimate changing your brakes around 25,000 to 35,000 miles.
  • Frequent highway driving and or light on the brakes. No hurry and take your time to stop. Estimate getting a visual inspection around 45,000 miles on factory brakes.
  • Noticing heavy brake dust, (black/brown powder on and around the wheels). Recommend a visual inspection as soon as possible.
  • If the brake rotors are visible through your wheels. Look at the rotors for heavy grooving, rainbow colors or dark patch discoloration on them.
  • Brake pads have an indicator on them. This metal indicator causes a squealing when the pads get too thin enough. Listen for this metal on metal squealing noise.

Starting from an aftermarket brake product, pads or shoes. You can figure on changing your brakes much sooner than factory ones. Based on the above estimates. Reduce the 25,000 miles to about 15,000 for a brake check and the 45,000 miles down to about 30,000.

If you are a Do-It-Yourselfer, or know a mechanic that will install the brand you like, here are my suggestions. I highly recommend these five brands. Wagner, Raybestos, Bendix, AC Delco or Bosch. All of these are offered in a ceramic, organic, semi-metallic and metallic. There are better brake brands available, they are a bit more expensive, but well worth it. Akebono, which is heavily used by car manufacturers. Hawk, which is the leader in ceramics pads. Centric and Powerstop also pads used by auto manufacturers and racers. To learn a little more about brake pads, click HERE

Ceramic Brake Pads

Ceramic pads are great for higher heats, harder stops and they dust very little if not at all. I have found that you get better miles out of them than regular pads. However a good semi-metallic or full metallic pad work well. Although, one of the things I find superior about ceramic pads, they are much easier on the rotor. When a pad has metal in it, (hence, metallic pad), that metal eats and groves the rotor.

Rotors are made so thin today that you pretty much have to replace the rotor when you replace the brake pads. In the old days, rotors were thick, so you could have them machined on each brake job. Now they are made right at the minimum thickness. Semi or full metallic pads eat the rotors down, so the time you need pads, you need a rotor. They are too thin to have machined. Having them machined is called. “Turning,” so you would say, get my rotors turned. Turning cost about $15 a rotor now. Brand new rotors on most cars, run from $20 to $50 each. Turning them isn’t even cost efficient. So the next time you change you brakes, plan on buying rotors.

Ceramic pads are composed of clay and porcelain bonded to copper flakes and filaments. They are more durable, grip really well and resist fading when extra hot. Out of all the brake pad types, ceramics are the best. The cost has come down so it makes more sense to buy them over the others. They are used on race cars and even heavy equipment and large trucks use them. On your next brake job, look into getting ceramic pads.

Don’t Forget About The Back Brakes

You will find that the back brakes wear at a different rate than the fronts. Vehicles have what is known as a proportioning valve made into the braking system. This valve allows a certain percentage of your brake pressure to be applied to the rear brakes. On average, vehicles only get 30% to the rear, meaning that the front brakes do around 70% of the stopping. That may sound crazy, but most vehicle’s engines are up front, so most of the weight is up front. Since your front brakes are first in forward direction, you want your stopping power there. If your brakes were set even to 50/50, you would see a lot of rear wheel sliding when you tried to stop.

So with 70% braking power up front, this is why you can go through two front brakes jobs to one rear. I would recommend a visual check on the rear brakes about half life on the front’s first brake job. when should I change my disc brakesVisual inspections are not always revealing, if you’re not sure what to look for. There are some brake pads that are made thin out of the box. So a quick look, might mislead you into thinking the pads are almost worn out. If in doubt, go to a parts store and ask to see a box of new pads. That will give you an idea of how thick they should be.

Be Careful At The Shops

If you are at a shop, and they are showing you how thin the pad is. Ask them to show you how thick a new one is before committing to a brake job. Often rear disc brake pads are thinner than the fronts. The shoes for rear drum brakes are also often thin. You may have to look at a new pair of shoes to determine the thickness of your old shoes. As mentioned earlier, you have to at least remove the drum on rear brakes to inspect them. Even rear disc brakes are hard to inspect without removing the wheel. Do not let garages tell you that you need to change your brakes until they prove it.

Always have a shop show you old parts vs new ones. It is sad to say, but there are shops that will take advantage of you on something like this. It is bad enough the over charge for brakes as it is. I have had too many customers run from these shops for price gouging. I had one customer come to me for a second opinion on her rear brakes. A shop quoted her $980 for pads and rotors. I priced the job for $300 due to the rotors were high. When I inspected her brakes, they were not even a quarter worn. Be careful of these rip off garages and always demand proof.




So, When Should I Change My Brakes?

I thought it would be best to show you images of what I have talked about so far. A list of things to watch for will be included below as well.

As I mentioned, visual aid is your best tool for deciding if you should change your brakes. If you are not mechanically inclined, take it somewhere. Have your brakes inspected by a professional. The best inspection is one where parts are removed and inspected thoroughly.

what is wheel brake dust

Look at your wheel for brake dust. A little is normal but if your looks heavy like in this image, inspect your brakes. If your vehicle is drum brakes, this really won’t apply. I will cover drum brakes below.

Grooved Rotors

when to change your disc brake rotors

If you have a sport wheel where you can see the brake rotor, this will make inspection easier. A brake pad that has worn down too far will groove the rotor. The grooves are easily noticeable, it will look something this image. If your rotor looks similar, then it is time to change your brake pads, most likely your rotors too.

Here is another example of what a grooved rotor looks like. This type of groove is a definite sign your pads are worn out.

what does a grooved rotor look like

Cracked Rotors

what does a cracked disc brake look like

If your rotor has a crack of any kind in it, you will have to change it out, and the brake pads. Cracks in a rotor are usually caused by the rotor getting too hot. Rotors can get hot for several reasons. Driver brakes to fast, abrupt and hard. Your caliper could be sticking, inspect the caliper.

Overheating Rotors

what does a over heated disc brake rotor look like

Another sign you need to change your brakes, is over heating rotors. Again, if you are hard heavy on the brake, like going from 70 to 0 in a couple of seconds. You can get similar coloring in this image. However, if you brake normal and get this discoloration, you are looking at more than just worn brake pads. In this image, these are high spots on the rotor. This will cause a pulsation or chatter when the brake is applied.

A caliper sticking can be caused by a piston hanging, frozen, not flowing, or traveling correctly. The caliper hardware is not allowing the caliper to slide and move correctly. Either one of these failures, will cause the caliper to keep too much pressure on the rotor. This doesn’t allow the pads to release pressure of the rotors, thus burning both rotor and pads up.

how can you tell if your brake rotor is over heated

If your rotors look like this, you are looking at pads, rotors, calipers, caliper hardware, or all of it. I strongly recommend to replace all of it due to the fatigue it causes all brake parts. Heat causes metal to warp and swell, and there is no reason to take a risk reusing possibly defective parts.

what does a normal disc brakes look like

Here is what a normal worn rotor should look like for a frame of reference. This is an average normal wear and tear brake rotor.

Let’s Take A Look At Drum Brakes

 

what are brake drums

This is what a normal wear on a drum looks like. The only real way to inspect drum brakes, is by removing the drum. There are signs that can indicate drum brake issues, and I will get to them shortly. Drum brakes are actually more complicated than disc brakes. You have a set of shoes, two shoes per drum. They are pushed away from each other into the drum to create resistance.

how do drums brakes go together

What makes drum brakes complicated is how the two shoes are tied together. They are assembled by springs, the self-adjuster, the hold downs and emergency brake connection.

Normal Wear

how to tell if a brake shoe is bad

If you pull the brake drums off for inspection, this is what a normal wear can look like. The shoe is also called the “brake lining”. Brake lining is the padding on the metal frame of the shoe. Lining can be glued on or riveted. Drum brakes are bad about keeping the brake dust trapped inside the drum. This dust and debris causes grooves to be cut into the lining and the drum. If the grooves are no worse than this image, just empty the drum of brake dust and blow off the shoes. Sandpaper can be used to clean up the lining.

Comparison

when do you change your rear brake shoes

This is a comparison of new brake shoe compared to completely worn out shoe. Even though your rear brakes only do roughly 30% of the stopping, when worn out, it requires that your front brakes to do more work. No matter drum or disc, usually your rear brakes are also the emergency brake. Start noticing if the car isn’t holding with the emergency brake on. If it seems pulling the handle is up further than normal or doing nothing at all. These are good indicators that your rear brakes need either adjusted or replaced.

Cracked Lining and Grooved Drums

why do brakes shoes crack

If your brake shoe lining is crack like in this image, you will need to replace them. Brake shoes are common to break and get cracks in them from all the heat that builds up inside the drum. When the shoe lining starts to crack, it’s possible the lining can break off in chunks. This can lock a wheel up from turning. If the lining is gone, the metal frame of the shoe can groove out the drum. This will cause you to have to replace it. So if you have cracked lining, replace it immediately.

what causes brake drums to get grooves

When you remove the brake drum to inspect the brake shoe, inspect the inside of the drum. Look for heavy grooves, coloration patches of metal grinding. If it has any of these, you need to change your brakes. The drums may just need turned, have them measured to see if replacements are needed.

Brake Adjustment

Improper brakes adjustments can cause premature wear, never over adjust them. With rear drum brakes, adjustments can make the brake pedal feel high. Often people will adjust it too tight to gain a tall pedal. Drum Brakes automatically adjust. This happens when applying the brakes and then letting off. You can achieve better auto adjusting if you role the car backwards and apply the brakes a bit harshly. This operates an arm that turns and adjuster wheel. As the brakes wear, it leaves free-play between the drum and the shoe. The free-play is what causes the lever to turn the adjuster. When there is no free-play, it stops adjusting.

how to adjust rear drum brakes

When doing a drum brake job, if you’re not sure the brakes are pre-adjusted correctly, here is what you do. Install the drum over the shoes and turn it. If the drum turns freely with no rubbing or a slight drag, then you need to turn the adjuster. This expands the shoes to move outward. You keep doing this until you hear and feel a consistent drag and noise. If it has become to hard to turn, you will need to back the adjuster off.

Sometimes it will feel like the drum is out of round. It will turn easy half way and then drag real hard the other half. With both drums on, push on the brake pedal and apply the parking brake a few times. This will center up the shoes in the drum, then you can go back to adjusting. Please note, if your brake pedal feels to low to the floor, but the rear brakes are adjusted. You have another issue, and tightening the rear brakes isn’t the solution. This could be air in the system.

 

Brake Drum Diagram

how do rear drum brakes work

 

Signs Your Brakes Need Attention

Outside all the visual inspections mentioned, it can be helpful knowing the last time you had a brake job. You should always keep some kind of maintenance record for your vehicle. If you noticed you have gone 50,000 miles on your current brakes, an inspection is past due. Below are things to pay attention to know when to change your brakes.

  • Heavy brake dust around the wheels (disc brakes)
  • Pay attention to the rotors through the wheel if possible to look for coloration’s and or grooves (disc brakes)
  • Make notice after getting out of your car, if you smell anything that smells burnt (disc or drum brakes)
  • Steering wheel seems to mildly go left to right when applying brakes (front disc brakes) (can occur with front drum brakes)
  • Car vibrates or shakes when applying brakes (front disc brakes) (can occur with drum brakes)
  • You hear grinding, growling or squealing noises when applying brakes (front disc brakes) (can occur with drum brakes)
  • The vehicle feels like the stopping power is pulsed or is surging (front disc brakes) (can occur with drum brakes)
  • Your brake pedal feels like it is pulsing up and down (drum brakes)
  • When using the parking brake, notice if the lever has to be pulled up further than usual (rear disc or drum brakes)
  • The parking brake is applied, but it will not hold the car in place (rear disc or drum brakes)
  • Brake indicator light comes on (check fluid level first, this can be a multitude of issues)
  • When the ABS indicator light comes on (vehicles with anti-lock brakes)

Wrap Up

These are some warning signs your brakes need attention and or replaced. On a side note, most parking brake levers are connected to the rear brakes with a cable. Emergency brake cables stretch over time, but they do have adjustments. Keep that in mind, if a garage is telling you need rear brakes because the emergency brake lever isn’t holding. Always ask if they have checked or adjusted the cable.

These are the most common things to look for, there are many things that can go wrong with brakes. I am not getting into the issues you can have with “Anti-Lock-Brakes”, that will be another post. Pay attention to the signs I have listed above but hopefully you have your car routinely maintained so your brakes will not get to any of these points.

Another important thing to know about brakes. Always replace in pairs, never replace one side and not the other. You can read more about why it is important to buy in pairs and sets HERE

 

  • I did not realize that back brakes wear at different rates than the front brakes. It is interesting to learn about the proportioning valve. My uncle says it is best to change brake pads before they are completely worn out to maintain the overall quality of your car.

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