Tutorial on Brake Pad Inspection and Replacement

Your brake pads are hard at work every time you stop at a traffic light, park your car, or stop for a pedestrian at a zebra crossing. These small but vital pads generate the friction required to slow the wheels and bring your vehicle to a stop. But all that effort has a cost: even though the brake pads are designed to be extremely durable, they will eventually wear out and need to be replaced. While the pads themselves aren't particularly expensive, having the work done at a garage can be quite costly.

Fortunately, you can do the work yourself at home. Changing brake pads is slightly more difficult than simply replacing a tyre or topping up brake fluid, but if you already have a good level of mechanical knowledge and are confident in your ability to do the job, you should be fine. This guide will explain when, why, and how to change your brake pads, including:

How do the brake pads function?

Brake pads are the component of your brakes that provides the friction required to slow or stop your vehicle. Each wheel's braking system consists of a brake disc, a caliper, and a pair of brake pads — the caliper and disc can sometimes be seen behind the alloys on certain models, such as the one pictured above.

The pads are installed inside the caliper, on either side of the disc. When you press the brake pedal, hydraulic pressure travels through the brake lines and forces the caliper shut, causing the brake pads to make contact with the disc. This creates the friction required to slow the spinning brake disc, which slows — and eventually stops — the vehicle.

Because stopping a speeding car requires a lot of force, brake pads are usually made of very tough materials that can generate the necessary amount of friction without overheating — typically, a blend of iron, copper, steel, and graphite is used. Nonetheless, they deteriorate over time, necessitating regular replacement.

How often should I replace my brake pads?

When you consider how much force is required to stop a car and how many times you will hit the brakes every time you drive, it's no surprise that all brake pads must be replaced at some point. However, not all brake pads wear down at the same rate for a variety of reasons, including your mileage, driving style, and vehicle weight.

The most important factor is how you drive. Driving aggressively, breaking sharply, and skidding the car all wear out your brake pads faster than prudent driving. If you drive in cities or are frequently backed up at intersections or in traffic jams, your brake pads will wear out faster because you will be hitting the brakes more frequently than if you were driving on a clear road in the countryside.

The weight of your vehicle — and whatever you're transporting — can also impact the life of your brake pads. The more force is required to stop your vehicle, the more friction the brake pads must endure. As a result, if you frequently transport a large number of passengers or keep heavy objects in your boot, the pads will wear out faster.

Mileage is another important consideration, as brake pads wear down faster the more you drive. There is no hard and fast rule, but your brake pads should be replaced every 25,000 to 60,000 miles, depending on the other factors we discussed above.

How will I know if my brake pads need to be replaced?

Most modern cars have brake pad wear sensors, which means that when one of the pads needs to be replaced, a warning light will illuminate on the dashboard. However, not all cars are equipped with sensors (especially older or vintage vehicles), so you'll need to check the brake pads on a regular basis or have them checked by a mechanic. We've listed some of the warning signs that one or more of your car's brake pads are wearing thin below.

Sounds of screeching or grinding

A metallic screeching noise is typically indicative of dangerously low brake pad wear. When a brake pad reaches the end of its serviceable life, a small metal shim is designed to grate again the rotor disc, alerting the driver that it's time for a replacement.

If you hear a loud, grinding noise, it's probably too late because the pads have already worn down completely. If this occurs, you should immediately stop driving the vehicle and arrange for a replacement as soon as possible.

When you brake, the car 'drifts.'

If you notice the car drifting to one side when braking, this could be due to a worn-out brake pad. It could also be a sign of an underlying problem with the alignment or overall braking efficiency, so have this checked out by a professional.

The pedal is vibrating.

When you press the pedal, it vibrates under your foot, which indicates that the brake pads are warped, worn, or damaged and must be visually inspected.

The pads are clearly worn.

If your vehicle does not have a brake pad indicator, you can visually inspect the pads for wear and tear. Most cars will require the removal of the wheel, though on some models, the outer brake pad may be visible through the spokes of the alloy wheel cover. The recommended minimum thickness for brake pads is 3mm; any thinner and the braking system will suffer serious damage. As a result, it's best to replace the pads once the thickness falls below 6mm.

What will I require?

You'll need the following tools and parts before you can start changing your brake pads:

A wire brush A floor jack Axle stands Screwdriver with a flat head C-clamp Socket set Torque wrench Allen key set (if applicable for your make and model)

It will help if you have the following aerosols and lubricants on hand:

• Copper lubricant
• Cleaner for the braking system

You will also require the following items for your own personal safety and comfort:

• Gloves for the workplace
• Eye protection is essential.
• A knee brace

Before you begin,

Before attempting to change the brake pads, ensure that you are confident and qualified to do so. Your car's braking system is critical to its overall safety and function, and performing repairs incorrectly could cause your brakes to fail. As a result, you should only attempt to follow the process outlined here if you have some experience with automotive repairs and are confident that you can do the job correctly.

The braking system can also differ significantly between different makes and models of car, so consult your owner's manual for more specific information.

Changing a brake pad in 9 easy steps

Step 1: Take off the wheel.

Begin by ensuring that your vehicle is securely parked on a level surface and that the handbrake is engaged. Loosen the lug nuts but do not completely remove them. Next, use a trolley jack to lift your car off the ground (instructions for this can be found in the owner's manual). Then, to keep your vehicle stable, place axle stands underneath it. Unscrew the lug nuts completely and set the wheel to one side.

Step 2: Remove the guide pin and clean the brake.

You should be able to access the brake disc and pad once the wheel is removed. It's likely to be filthy with dirt and brake dust, so give it a quick clean with the brake degreaser. Then, using a spanner, remove the guide pin. a spanner to secure the guide pin while unscrewing and removing the guide pin bolt If it is stuck, you may need to use lubricant.

Step 3: Take out the calipers.

After that, unscrew the caliper bolt and slide it out. If it won't budge, use a pry bar or flat head screwdriver to gently pry it out. Pulling the caliper too hard once it's loose can damage the brake hose.

Step 4: Take off the brake pads.

Remove the clips that hold the brake pads in place and set them aside — be careful not to lose them! Then, remove the brake pads from the mounting bracket. They should be easy to remove, but if not, a few gentle taps with the butt of your screwdriver may help.

Step 5: Examine the brake disc and lines.

Examine the brake disc and line in greater detail. The disc should be smooth and shiny, with fine lines running through it. If you notice any deep grooves scored into the surface, the disc must be replaced. Keep in mind that brake discs should always be replaced in pairs.

Check the brake lines next. Rubber hose lines should be flexible, not cracked or hard. Check the metal hose lines for signs of wear, damage, or corrosion as well. A faulty or leaky brake line can cause serious problems, so if you suspect a problem, seek professional assistance.

Step 6: Replace the brake pads.

Insert the new brake pads and secure them with the clips. Apply a small amount of copper grease to the edges of the brake pads, taking care not to get any on the friction linings. After that, reinstall the caliper and tighten the bolts.

If this is difficult, it is possible that the caliper has been adjusted to accommodate the thinner width of the old, worn-down brake pads. In this case, you'll need to adjust the caliper piston tension — consult your owner's manual for instructions. Most modern vehicle calipers are wind-back calipers, so you'll need a caliper rewind kit and the appropriate type of attachment. This job will be made easier by removing the brake fluid reservoir cap.

At this point, it's also a good idea to check the caliper piston boot for signs of wear or damage. We'd also suggest lubricating the sliding pings at the same time.

Step 7: Examine the brake fluid

After you've completed both wheels, press the brake pedal a few times to bring the brake pads into contact with the brake disc. You may need to top up the brake fluid, so check the reservoir level — more on this in our guide to topping up brake fluid.

Step 8: Change the wheel.

Replace the wheel on the axle. Secure the lug nuts loosely, but do not tighten them yet.

Step 9: Lower the vehicle and secure the lug nuts.

Lower the jack and remove the axle stands. When the car is back on the ground, completely tighten the lug nuts to secure the tyre, working diagonally. Congratulations, you have just changed your brake pads.

Now that you know how to change brake pads, you're ready to get started — head over to our brake parts store to make sure you have everything you need, including brake discs and pads, before you begin. More informative how-to guides on everything from changing a tyre to flushing the coolant system can be found in our auto knowledge hub.

Although changing brake pads is not a difficult task, the braking system is critical to the safety of your vehicle, so it is critical that this work is done correctly. As a result, we would only recommend doing this job yourself if you are certain you can do it correctly. GSF Car Parts cannot accept liability for damage caused by incorrect repair work because all makes and models of cars have different requirements.