How to diagnose and repair brake issues
Tuesday, 12 March 2019
There are many issues that can arise with the braking system on your vehicle.
Whether it be noisy brakes, longer stopping distances or a shudder through the steering wheel or body of the vehicle when slowing down, they are all indications that your braking system requires attention.
Fortunately, some of these inspections and repairs are something that you can carry out yourself, with a little help from this article!
There’s nothing worse than driving down the street with your car emitting loud, squealing or grinding noises every time you apply the brakes to slow down.
It almost makes you want to slump down and hide!
There are many reasons why your brakes could be causing this noise, especially if you have not had your brakes replaced recently.
Both disc brakes and the older style drum brakes can cause these noises, and the most common reason is a buildup of brake dust.
This buildup can sit on the face of the brake pads and also block up the cooling channels, which causes a squeaking noise when slowing down.
When it comes to drum brakes, if the drums are not cleaned out on a regular basis, the buildup of dust will affect the performance of the brakes, as well as causing a squealing noise.
DIY BRAKE CLEAN
If you are confident enough in your abilities, you can carry out the cleaning process yourself.
- Floor jack and jack stands
- Ratchet and socket set
- Brake cleaner and rags
- Wire hangers
- Brake lubrication grease
- Flat blade screwdriver
- Sandpaper and wire brush
- Brake grease (Available at auto parts stores)
Work out where the noise is coming from, whether it’s the front or the rear of the vehicle. Have another person stand outside the car and as you drive past, apply the brakes. You may need to drive past in both directions, to narrow down the noise.
Once you have isolated the area where the noise is coming from, park the vehicle on a flat, even surface.
Loosen the wheel nuts slightly and raise the front or the rear of the car, using a jack, and once the vehicle is raised, place a jack stand under the vehicle.
NEVER work on a vehicle that is supported by just a jack, as it may fall and cause serious injury or death.
Remove the wheels completely, and inspect the brakes. If the pad thickness is ok, and there is no damage to the brake disc, the main cause of the noise will be brake dust.
Remove the brake pads from the vehicle by loosening the lower caliper slide bolt with the appropriate tools, and remove the caliper housing from the vehicle.
Support the caliper by using a piece of wire to secure it to a suspension component and up out of the way.
Using the flat blade screwdriver, remove the brake pads from the caliper bracket and inspect them for uneven wear and buildup of brake dust.
If the brake pads are worn unevenly, they will need to be replaced and the caliper inspected (covered below).
If the brake pads are worn evenly, rub the face and the edges of the brake pads with sandpaper, to remove any sharp edges and clean the brake pads with brake cleaner.
Set them aside and allow them to dry.
Whilst your brake pads are drying, inspect the brake disc for any damage.
If the rotor is a slightly blue colour, has small cracks, or has an uneven surface, the pads will need to be replaced. We will cover this further on in the article.
If the discs are in good condition, apply a small amount of brake grease to the top and bottom of the brake pads and refit them into the caliper bracket.
Slide the caliper housing back over the top of the brake pads, and refit the caliper bolt. Carry out on the other side and refit the wheels.
Test drive the vehicle in a quiet street to confirm the noise has gone.
If your vehicle is fitted with brake drums, the process is very similar.
Once you have jacked the car up, and removed the wheels, the next step is to remove the brake drums from the car.
Using the hammer, slightly tap around the face of the brake drum, being careful not to hit the wheel studs in the process. This will loosen any corrosion holding the drums on.
You may notice brake dust coming from the drums when you hit them, be careful to not breathe in this dust, as it can be harmful to your health.
Once the drum is loose, simply slide It off, and empty the dust into an appropriate container.
Using some brake cleaner, wipe the inside of the drum, and run sandpaper around the inside of the drum, until it is smooth. This will give the linings a fresh surface to run on.
Use your brake cleaner and rag to clean the surfaces of the brake linings and other components, and allow to dry.
You can also carry out an adjustment of the brake linings with the drums removed.
Simply use your flat blade screwdriver and adjust the small wheel in the middle of the linings.
It will look like a small wheel with teeth on it, and will click when it is adjusted. It should only spin in one direction.
Adjust in small increments, and refit the drum, to make sure it has not been adjusted too much. Once you feel a very slight drag on the drum, the system is adjusted correctly.
Carry this out for both sides of the vehicle, refit the wheels, and test drive the vehicle in a quiet street to confirm the noise has gone.
STEERING WHEEL SHUDDER – BRAKE REPLACEMENT
If you have noticed a shudder through your steering wheel when slowing down from higher speeds, it is more than likely that your brake discs are slightly warped and your brake pads are wearing unevenly.
This will require the replacement of both the brake discs and brake pads and an inspection of the brake calipers.
This is also the case if you notice your brake pedal travel has increased.
These new components can be bought from auto parts stores such as Supercheap Auto.
With brakes, purchasing quality products will ensure that the braking performance of your vehicle remains consistent and provides the best level of safety for you, your family and other motorists.
Once you have purchased your new brake components, it’s time to fit them up! Follow the procedure above, to jack up the car, remove the wheels and brake components.
Remove the brake caliper bracket and place to one side. Then remove the brake disc. This removal process may be the same as removing the brake drums by slightly tapping the edge of the brake disc with a
hammer, to loosen the corrosion.
There may also be a locating bolt that needs to be removed before the disc will come off.
Once removed, use the sandpaper and wire brush to remove any corrosion from the hub assembly, and then fit up the new disc.
Clean the face of the disc with some brake cleaner to remove the anti-corrosion material, and refit the locating bolt if required.
Refit the caliper bracket, and slide the new brake pads into the bracket, making sure to apply brake grease to the top and bottom of the pads, to allow them to slide freely in the caliper.
The next step involves pushing the brake piston back into the caliper. You can buy a specialty brake press, or just use one of the old brake pads on the face of the piston and push it back with a G clamp or a large set of multi grips.
Be careful not to rip or tear the dust boot that goes around the piston, as this can allow debris to enter the brake fluid.
Once the piston is back in the caliper, remove the caliper slides – these will just pop out of the caliper bracket - and make sure they move freely and the grease isn’t contaminated. If it is, simply wipe the old grease off with a rag and reapply new grease.
Refit the caliper housing to the bracket, making sure to torque the bolt to the correct tightness. Carry out the same process on the other side of the vehicle. Once complete, refit the wheels back onto the car, and lower back onto the ground.
This is the most important part of the installation process, whether you have just cleaned your brakes, or fitted new brake pads and rotors.
Braking systems require what is called ‘Bedding in,’ which transfers some of the new friction material off the brake pads onto the new brake discs.
Without carrying out this step, the braking system will not operate correctly and will cause increased stopping distances and brake squeal – the issues that made brake replacement necessary in the first place!
To carry out the bedding in process, find a quiet street with little to no traffic.
With no one behind you, accelerate to 40km/h and apply the brakes firmly, so the vehicle almost comes to a complete stop.
Carry out this operation 5-10 times, allowing 30 seconds between stops to allow the brakes to cool sufficiently, so they do not overheat.
Then, increase the speed to 60km/h and repeat the process. This will ensure proper operation of the braking system.
Once this operation is complete, park the vehicle on a level surface, but do not apply the parking brake.
As the brakes are hot, using the park brake will cause an uneven spot on the brake disc, which will cause a shudder further down the track.
Following these instructions will allow you to diagnose and possibly repair your brake system issues, but if it seems a little overwhelming, or you are worried about not completing the job safely, it is best to get a professional to carry out the repairs required.
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Finding a passion for cars from a young age, Joel carried out work experience as a mechanic whilst at school before starting an apprenticeship after finishing year 12.
After almost 10 years on the tools and in customer service, he moved into the IT realm as a Data Analyst and In-House mechanic at AutoGuru.